carbonfiber/kevlar layup

[mrconcrete]

after about 8 months of not working on the boat..I am back at it.

It is going to be carbonfiber/kevlar layup with no core...what do you think putting down 2 layers of 5oz kevlar followed by one 5.7oz carbonfiber followed by 2mil coremat (in the areas the old core was) and then 2 layers of 5.7 carbonfiber? total cost on all that less epoxy is 550.00 I got a deal..thats less than screwing around with atc corebond and a composite core.

I know the pros and cons but I want NO wood.

I belive it will be lighter and a hell of alot stronger

a pic of where I left off at...should I use 2mil or 4mil coremat?

[kytekeith]

Is that a stream with a concave pad?

[mrconcrete]

yes, vector... concave and hooked

[baja200merk]

Most comp boats didnt have a core but they had 4 stringers

[kytekeith]

yes, vector... concave and hooked
What year ,and what kind of power is going on it?

[Gorilla0178]

I'm not a huge fan of the coremat, it yealds no strength it just absorbs resin. By its self it breaks like a cracker. (if its the same coremat that we used to make consoles out of) I would rather see you use 1/8" k-mat or something like that. Its the same thickness, but it is actually a foam core product. Just an opinion. With all the high tech materials going into it, the coremat would be low tech in compairson.

I also agree with the stringer coment, with no core you'll need more stringers spaced closer together. The material your putting into it wont build up much bulk or thickness. I probably would go with a 1/2" scrimed and scored core. Kevlar,Kevlar,Carbon, putty,core,Carbon,Carbon,6or8oz finishing cloth. The cloth is so you can sand it smooth and not burn through the carbon. Carbon sands real real easy be careful

[mrconcrete]

I'm not a huge fan of the coremat, it yealds no strength it just absorbs resin. By its self it breaks like a cracker. (if its the same coremat that we used to make consoles out of) I would rather see you use 1/8" k-mat or something like that. Its the same thickness, but it is actually a foam core product. Just an opinion. With all the high tech materials going into it, the coremat would be low tech in compairson.

I also agree with the stringer coment, with no core you'll need more stringers spaced closer together. The material your putting into it wont build up much bulk or thickness. I probably would go with a 1/2" scrimed and scored core. Kevlar,Kevlar,Carbon, putty,core,Carbon,Carbon,6or8oz finishing cloth. The cloth is so you can sand it smooth and not burn through the carbon. Carbon sands real real easy be careful

Thanks for the help...and yes I am putting in stringers kneebraces all the BS.

[mrconcrete]

What year ,and what kind of power is going on it?

77..300+ 12" mid ,1.87 sporty

[mrconcrete]

the more I think about it I will probably put a piece of corecell in instead of the mat.

[Gorilla0178]

Oh yeah corecell, the good stuff. Sounds like a plan.

[tunnels]

after about 8 months of not working on the boat..I am back at it.

It is going to be carbonfiber/kevlar layup with no core...what do you think putting down 2 layers of 5oz kevlar followed by one 5.7oz carbonfiber followed by 2mil coremat (in the areas the old core was) and then 2 layers of 5.7 carbonfiber? total cost on all that less epoxy is 550.00 I got a deal..thats less than screwing around with atc corebond and a composite core.

I know the pros and cons but I want NO wood.

I belive it will be lighter and a hell of alot stronger

a pic of where I left off at...should I use 2mil or 4mil coremat?

Time for a little thought to go into what you are going to do . Number one NEVER USE COREMATT IN THE BOTTOM OF A BOAT ! ANY BOAT !!!!!REGUARDLESS OF THE THICKNESS AND WHAT RESIN YOU ARE USING !!!!
Can use it in the topside but NEVER in the bottom !! core matt will not stand any kind of flexual movement for any great period of time . and will shear and separate . DONT DO IT !!!!!

Kevlar has a lots of streach and wont let go . Carbon has no streach and will break before it lets go .
You would have to deal with the carbon and the kevlar using epoxy resin and nothing less!!
Unidirectional fibre would be my choice just the oriantation of the strands would be the critical factor to gain the max amount of rigidity and stiffness from it !!.
If you not having a core in the bottom then a couple of stringers each side will do wonders for what are looking for as well as the carbon fibre as the final top layers and stringers over the top of that with some good double bias cloth to hold them in and down onto the carbon . :thumbsup: :D

[tunnels]

I'm not a huge fan of the coremat, it yealds no strength it just absorbs resin.

Need to put the record straight here!! do you understand what corematt is used for normally ??
Anyone know !!
Im going to wait for a reply or two and see if anyone is on the right track and understands the properties of core matt and its uses !!

:confused::confused::confused::confused::eek::confused::confused::confused::confused:

[mercurypro]

core mat is a stiffner .. used between 1808 etc.. make a sandwich type

[Capt.Insane-o]

No core in a 300 hp vector...........wow.

I'm sure the factory comp boats had a different skin lay up than the standard cored productions to toughen them up. The standard production boats skin is ass. I'd at least core the stressed running surfaces with some 1/4 composite something and the pad and inner areas with regular 3/8 or 1/2inch. I still don't see the facination of using carbon in a shell that is layed up like a ritz cracker to begin with.

Running a non cored older 'stream with that kind of power is just asking to get your ass handed to you.

[mrconcrete]

No core in a 300 hp vector...........wow.

I'm sure the factory comp boats had a different skin lay up than the standard cored productions to toughen them up. The standard production boats skin is ass. I'd at least core the stressed running surfaces with some 1/4 composite something and the pad and inner areas with regular 3/8 or 1/2inch. I still don't see the facination of using carbon in a shell that is layed up like a ritz cracker to begin with.

Running a non cored older 'stream with that kind of power is just asking to get your ass handed to you.

the pad will be cored....it also is getting C/F directional tape put down first.

I dam near have all the old chit ground out as whats left is paper thin anyway..hell I am down to the black gell they put down after the flake in a lot of areas..LOL

If all the old **** peels off than at least I will have something left to ride in

[power of one]

Mr Concrete i,m with gorilla and tunnels coremat sucks it is a poor mans stiffner between chop strand just remember you can use stitch cloths like quad and vinylester with Klegecell stringers will still make for a light strong rig and won,t hurt the pocket space them 300 -400 mm apart a couple of gussets 10 mm kleg floor quad both sides your away however your kevlar carbon is a good idea though how much glass is in the shell allready is it worth the hitech materials .

[Gorilla0178]

I'm not a huge fan of the coremat, it yealds no strength it just absorbs resin.

Need to put the record straight here!! do you understand what corematt is used for normally ??
Anyone know !!
Im going to wait for a reply or two and see if anyone is on the right track and understands the properties of core matt and its uses !!

:confused::confused::confused::confused::eek::confused::confused::confused::confused:

No answers yet. We just used it in cheap layup for consoles between mat and stitchcloth. I've seen material like it used as flow media for infusion but not sure if its the same. I thought it was just a bulk builder or a print blocker to block print through.
Any answers close????

[mercurypro]

( quote it is a stiffner used between layers ) this is from my rep who has sold the products for 0ver 25 years for the number 2 largest dist of resins etc.. and too the largest yacth mfg in the north..and your answer is .. and yes i use it .. but i dont like it

[tunnels]

Core matt you either like it or you dont !! i hope everyone will have a rethink about what iv'e written on this subject !
The thing is it used for things and in places it was never intended to be used and theres that preconcieved idea it soaks up resin !! yes it does soak resin because thats what it is designed to do to give you thickness .

ok lets get to the basics and you can draw your own conclussions for it
Like the name says its a core yes and its made from A glass matt thats been bulked with displacement Q cells .
Now has anyone actually disected it and had a really close look at what your buying .
It was advertised in the early days as a stiffener and bulking layer for not only flat areas but also products that have shape, curves, hollows, and humps and lumps . Places where its just about impossable to lay a foam or balsa core without having a lot of problems getting it in and stuck down .

Its also used a glass replacement to speed up the manufacture of a solid glass panel of a given thickness .
Example= if you need a 1/4 of solid glass then you would lay down 2 layers of csm + 3 mm core matt + 2 layers of csm ,when wet out you would have your solid glass panel but a little lighter because corematt dosent use as much resin as 3mm of solid glass , it also gives the benefits of rigidity being a core that conforms to almost anyshape when its wet .
Over the years a million uses have been found for it . But it has a problem of shearing under bending loads such as the bottom of a hull where it flex's hundreds of times a minute when powering across the surface . Hull sides ok also as a print through blocker under a foam or balsa core, but its the thinner corematts that are used there . and it should also have a layer of glass between the core and the core matt . The worst thing you can do when using core matt is not put enough resin on it . If you follow the instrucion sheet it will tell you x amount of resin to wet out x square feet of x thickness of core .
I find its best to wet it so it is runny wet then put a dry layer of glass over the top and roll it over with a mohair roller , the mohair picks up the surplus resin and wets out the dryer places but it should still be wet enought to gently roll with a steel laminating roller , Notice i said gently roll not lean on the roller trying to squeeze it so the resin comes out ,That action is defeating the purpose of using the corematt .
Looking at it realisticly it using less resin anyway for the given thickness of lay up its creating and giving you the added benefit of stiffening that area as its a flexable core matt material !!:rolleyes:
Its not the corematt thats the problem it how we have been bought up to think about it , change you thinking and you will see its a fantastic material when understand how it works and use properly . Like all good things it has its draw backs !.
Its good to use and has excellent compression strength as a bedding layer under things getting bolted down its not as hard as solid glass but harder than most woods solid or ply !!
Never under wet it !! when it has all the resin it needs it should look and be completely soaking wet and best to put a layer of dry glass over and wet that was well !!!!!:thumbsup:
:D:thumbsup:

[tunnels]

No answers yet. We just used it in cheap layup for consoles between mat and stitchcloth. I've seen material like it used as flow media for infusion but not sure if its the same. I thought it was just a bulk builder or a print blocker to block print through.
Any answers close????

You are partly right on both accounts !!get a sample next time to disect and slowly tear apart to understand what and how its there for
What you are refering to is very simular and is there to do a simular job as core matt !! its to give the lay up thickness . Think about this!!!
If you have 1/4 of a layer and squeeze it to half that thickness then you wont have the same rigidity as when it was 1/4 thick !!, Infusion squeezes and compresses the layers of glass and so a good amount of rigidity is lost Engineers had to come up with a bulking layer to get back to the simular thickness but not use the same amount of resin as the original layup .
Core matt does the same job in a standard hand lay up . !! Core matt uses less resin for a given thickness than solid glass lay up .
Undrestanding the materials we work with and use is not that hard .:thumbsup:

[XstreamVking]

Allways thought coremat was just good for eliminating the possibility of woven or bias glass from printing thru. And for mold making coring. Never would use it for a light wt. race hull. Use the weight of the resin and coremat to make some short stringer sections..Would be stronger i believe...

[OFFSHORE GINGER]

Understanding materials is basically very easy like Tunnels stated but i have seen to much de lamination from it and with that in mind one prime example is on Wellcraft Scarab's , where time and time again , i have seen more then one bottom of the motor compartment area ( running surface ) totally delaminated because of core mat and these boats did not even do triple digits so if you all want to use it by all means do so and like TUNNELS said its all about understanding materials and to tell you the truth from my past experiences with core mat , i would not have the stuff shoved up my a$$ .

[racerx]

Allison boats use cormat,and i have had great luck with an allison...How would you repair a crack in a kevlar boat?Would fiberglass matt and resin be good?Thanks

[Gorilla0178]

Well its always nice to learn something new and more about something you've used before. I personaly have used and I'm not exaggerating hundreds of rolls over the years building center consoles. We built hundreds and hundreds of them each year. I cant even guess how many rolls of material i've cut. I was the only guy at the shop that did all the material cutting and we built them every day. I've disected coremat before and it looks just like tunnels said, a glass mat filled with what I didn't know was q-cells but that explains alot. We used everything from 1mil to 5mil, the 3-5mil needed to be pre wet on one side before it was put down cause the resin wouldnt soak through the thicker material. Thanks for the info.

[tunnels]

Never would use it for a light wt. race hull.:eek:

Need to re read what i wrote about its uses . This is completely the wrong thing to use if you are trying to save weight , thats not what its meant to be used for anyway !!. :confused:
In the begining it was used for the industrial glassing industry but like everything found its way into Boats .:rolleyes:

[Gorilla0178]

Allison boats use cormat,and i have had great luck with an allison...How would you repair a crack in a kevlar boat?Would fiberglass matt and resin be good?Thanks

Like tunnels said, it can be used in topside parts but it shouldnt be used in the hull of a high perf. boat. If you take a piece of coremat and wet it out, when its cured it will break like a cracker. It has no strength by its self. Repair the crack like any other, I would add a little extra. If you had a little kevlar I would repair it with that.

[tunnels]

Understanding materials is basically very easy like Tunnels stated but i have seen to much de lamination from it and with that in mind one prime example is on Wellcraft Scarab's , where time and time again , i have seen more then one bottom of the motor compartment area ( running surface ) totally delaminated because of core mat and these boats did not even do triple digits so if you all want to use it by all means do so and like TUNNELS said its all about understanding materials and to tell you the truth from my past experiences with core mat , i would not have the stuff shoved up my a$$ .

Who ever spec the use of corematt in the bottom a boat like that has never done time on the floor of a glass shop of done repairs and certinly dosent understand glass materials .
The first time i ever saw it used in the bottom of a boat i shuddered . Sure enough the boat was back with the whole bottom blown off from chine to chine and there was just the inside skin keeping the water out .

Please take note of what i am going to say!!
THERE IS ONLY ONE CORE FOR THE BOTTOM OF A HULL AND THATS BALSA !!

:cheers: Have a good new year !!! :cheers:

[Gorilla0178]

THERE IS ONLY ONE CORE FOR THE BOTTOM OF A HULL AND THATS BALSA !!

:cheers: Have a good new year !!! :cheers:[/QUOTE]


Only balsa???? I dont want to start another one of these debates but thats harsh :D

Happy new year to you too!!!!!!!:cheers:

[tunnels]

Well its always nice to learn something new and more about something you've used before. I personaly have used and I'm not exaggerating hundreds of rolls over the years building center consoles. We built hundreds and hundreds of them each year. I cant even guess how many rolls of material i've cut. I was the only guy at the shop that did all the material cutting and we built them every day. I've disected coremat before and it looks just like tunnels said, a glass mat filled with what I didn't know was q-cells but that explains alot. We used everything from 1mil to 5mil, the 3-5mil needed to be pre wet on one side before it was put down cause the resin wouldnt soak through the thicker material. Thanks for the info.

You are using for things it was meant to be used for stiffening and to do away with solid glass panels .
Consoles need to be stiff, robust and get things screwed and bolted to them so its perfect for that also seats and boxes and internal paneling such as coamings etc etc .
Yes its best to wet out the underside first and then turn it over and wet the top as well but again dont skimp on the resin , those little bleed holse should be filled with resin !! if they arent its not wet enough !!!
So when you wet it out if the resin is running out just put a layer of dry glass over the top and mohair roll it !! Try it !! it works a treat believe me .
Like you i to have used acres of the stuff . A saturator gun is the best to wet it with because its quick and you get a good amount of resin on the underside to bring it up to the surface specialy in the 2 or 3 mm thickness .I must admite the name is a bit misleading core matt.
In Korea we used loads as a way of building the thickness quickly on the moulds we were making for the 36 ft match racing yachts .There was non used anywhere in the actual boats just the moulds thats all !!. :thumbsup:

[tunnels]

THERE IS ONLY ONE CORE FOR THE BOTTOM OF A HULL AND THATS BALSA !!

:cheers: Have a good new year !!! :cheers:


Only balsa???? I dont want to start another one of these debates but thats harsh :D

Happy new year to you too!!!!!!!:cheers:[/QUOTE]

On this site i feel we are here to try and keep it simple and to keep people out of trouble and make life easy for all to understand and do the work .
Only use balsa in the bottom of powerboats ! is that simple enough , what you use in the topsides is a whole differant story !
If you say use foam you need to specify the name and its density , its type and the manufactures name !!.
Balsa is balsa !!!
P V C Foam is a whole differant thing !,theres a list as long as you arm and not all are suitable for one particular job .
And if your thinking nomex honeycomb , paper or aluminium then you are in the wrong place .
Simple things work best !!!

[OFFSHORE GINGER]

Never would use it for a light wt. race hull.:eek:

Need to re read what i wrote about its uses . This is completely the wrong thing to use if you are trying to save weight , thats not what its meant to be used for anyway !!. :confused:
In the begining it was used for the industrial glassing industry but like everything found its way into Boats .:rolleyes::icon_bs::icon_bs: Dude you really need to read my last post & who fricken mentioned anything about a light lay up for a race hull ? (hellooooooooooooooooo)or ( can you not read ) Did i not mention a Wellcraft Scarab , that is a production boat and once again does not even see triple digits .Tunnels , sometimes you twist things so far out of shape that there is no f***ing logic comeing from you at all!

[OFFSHORE GINGER]

Allison boats use cormat,and i have had great luck with an allison...How would you repair a crack in a kevlar boat?Would fiberglass matt and resin be good?Thanks First off i would not use Matt or a conventional resin . I would go with epoxy and Kevlar for the repair .

[OFFSHORE GINGER]

THERE IS ONLY ONE CORE FOR THE BOTTOM OF A HULL AND THATS BALSA !!

:cheers: Have a good new year !!! :cheers:Happy New Year to you also :cheers:


Only balsa???? I dont want to start another one of these debates but thats harsh :D

Happy new year to you too!!!!!!!:cheers:[/QUOTE] I also agree that the topic of Balsa core could turn into a very heated topic and yes i also use Balsa . :D :D;)

[power of one]

So what deciion did Mr Concrete come too after another thriller by all concerned at least we all love boats . :cheers: and the fine materials involved or 99% of them .

[mrconcrete]

So what deciion did Mr Concrete come too after another thriller by all concerned at least we all love boats . :cheers: and the fine materials involved or 99% of them .

I didn't think I would need a core with using high strength materials and stringers..but..after all the "experts" chimed in....

I was just wanting to gain some thinkness with the coremat

I will probably use corecell..kevlar,kevlar,carbonF,corecell, carbonF, carbonF

and something else in the pad thats yet to be determined.

Bill

[tunnels]

I didn't think I would need a core with using high strength materials and stringers..but..after all the "experts" chimed in....

I was just wanting to gain some thinkness with the coremat

I will probably use corecell..kevlar,kevlar,carbonF,corecell, carbonF, carbonF

and something else in the pad thats yet to be determined.

Bill

Ok so you are insisting on using corecell !:eek:
Have you settled on the grade (theres a few to pick from )and the density (now this is the problem area )???
What thickness????(why are you intending 2 thin layers? )
Have you thought about getting purfirated or non purfirtaed ??
The first layer (to the old laminate) you intend to put down is stuck down with ??
and how do you intend to put it down ???
Why 2 layers of core cell ??
and why kevlar and carbon ??
They are 2 completely opposite materials one with a load of streach and one with no streach

Carbon /kevlar--corecell thickiness 15mm --kevlar /carbon/carbon would be a better option
and make the corecell one layer with the combined thickness that you were intending when you were going to use 1/4 X 2 layers =1/2 inch ?

Have you read all the information on core cell ?? :rolleyes:
Remember Yacht construction any size and big powerboat construction from 24 ft upwards and small hi speed power boat from 10ft to 23ft plus construction are all completely differant from each other !!
Small powerboat construction is the tricky one and thats the one where engineers fall flat on there behinds with and get it all wrong . :confused:
With this type of layup using kevlar and carbons etc you have no choice but to use nothing less than a good Epoxy thoughout !!

[Gorilla0178]

I think he was saying he was going to use corecell, then gave the lay up. I read it as kevlar,kevlar,carbon,corecell,carbon,carbon. The 2 corecell words were just used too close together. If he doesnt want to use core, or was trying to get away from it he could always bulk up those area's with heavy glass,(woven roving ect.) I know the end weight will be heavier but he wont have to worry about core. My rebuild never had core, and I didn't put any back. But you should see how thick the pad area and center of the boat is. With all the overlap from the stringers and the overlap from the glass I put in, I'm pretty sure the pad is at least 1"thick, which is fine for me I knew it was going to be anyways but the bottom is very solid. As far as the question about the material used, using the carbon and kevlar will produce a very strong light layup, but there won't be any bulk to it, I think it would be to thin for the bottom of a boat, now if it was for the cap then it would be better. I've built boats out of all carbon, and out of all kevlar, but the material was alot heavier than the stuff your talking about using, like 1308 kevlar, 24oz kevlar, 10oz and 16oz carbon. Its alot thicker.

[Gorilla0178]

Only balsa???? I dont want to start another one of these debates but thats harsh :D

Happy new year to you too!!!!!!!:cheers:

On this site i feel we are here to try and keep it simple and to keep people out of trouble and make life easy for all to understand and do the work .
Only use balsa in the bottom of powerboats ! is that simple enough , what you use in the topsides is a whole differant story !
If you say use foam you need to specify the name and its density , its type and the manufactures name !!.
Balsa is balsa !!!
P V C Foam is a whole differant thing !,theres a list as long as you arm and not all are suitable for one particular job .
And if your thinking nomex honeycomb , paper or aluminium then you are in the wrong place .
Simple things work best !!![/QUOTE]

I agree :cheers: Balsa is the easiest to work with and the most economical. Also it would be pretty easy to get the wrong density core if you didnt know what you were looking for. And the list is probably longer than your arm. I've never used the paper or aluminum honeycomb and i dont know why anybody would build a boat with paper, or aluminum honeycomb, The aluminum wouldnt last too long once exposed to salt.

[tunnels]

Just read through the Corecell spec sheet and it is just the same as any other pvc foam . :confused:
Like i said a lot a times before Balsa is your best choice and i will stick to that decission .
Its flexual and core shear that is the issue with small boats and great piles of laminate is not the answer be it glass of what ever .:eek:

To do what you are doing this would be my choice of mateials and lay up
1.5 oz csm with a Double bias Glass with a 1.5 oz csm as you first layer !
The core a Balsa 3/4 inch sucked into core bond .
a 1.5 oz csm and a double bias glass over with a 2 oz undirectional glass set at 90 degress to the keel line and a 1.5 oz over the top with a layer of peel ply well rolled into the top laminate to finish off with !
Resin would be all Yinylester
All layers ovelaping in the pad area with 2 extra double bias layers running full length of the pad coming out 2 inchs under and over the core during the lay up so it is sandwiched inbetween the layers of glass .

The uni on the inside will give you ridgidity and work in conjunction with the 3/4 core .The bottom will have very little movment at all and i wouldnt have any stringers just a centre keel for the inside floor to sit on top of !!

Someone some where is going to ask why no stringers ! any one know why ?? Anyone what to take a guess??:confused:

The cost of materials would be much less i would say.

Double bias matt comes with a csm stitched to one side if you can get it then one 1.5 csm on each layer can be left out !

[mrconcrete]

Gorilla read it right..kevlar,kevlar, carbon/f, core,carbon/f,carbon/f

That was the thought of using coremat in the first place..to gain thickness..I don't care about what the strength of the core is.thats what the carbons for.

Kevlar is going down first because of the impact resistance, then the carbon for strength.

Wood.....is totaly out of the question for me anyway.

[Brabender]

Not to hijack your thread

But tunnels do you think this is an acceptable
use of coremat in this stream

<a href="http://tinypic.com" target="_blank"><img src="http://i48.tinypic.com/2n99es1.jpg" border="0" alt="Image and video hosting by TinyPic"></a>

C

[tunnels]

Gorilla read it right..kevlar,kevlar, carbon/f, core,carbon/f,carbon/f

That was the thought of using coremat in the first place..to gain thickness..I don't care about what the strength of the core is.thats what the carbons for.

Kevlar is going down first because of the impact resistance, then the carbon for strength.

Wood.....is totaly out of the question for me anyway.

"I don't care about what the strength of the core is".
You had better think about the strength of everything specially the core as this is going to crap out very quickly and all the rest will be doing very little just flapping in the breeze !! and youll be back scratching those round hairy things wondering what happened and why !!:eek:

Point to always remember when building a boat , Its only as strong as that stuff up you covered up when you were making it !!

Time to add my favorite phrase again ! 80%of all failures are from bad workmanship and the other 20% is just bad choice of materials !

[tunnels]

Not to hijack your thread

But tunnels do you think this is an acceptable
use of coremat in this stream

http://i48.tinypic.com/2n99es1.jpg (http://tinypic.com)

C
Corematt in the topsides is ok and just about every powerboat builder uses it to gain a little more stiffness . Just dont use it in the bottom anywhere !!! :thumbsup:

[mrconcrete]

"I don't care about what the strength of the core is".
You had better think about the strength of everything specially the core as this is going to crap out very quickly and all the rest will be doing very little just flapping in the breeze !! and youl be back scratching those furry things wondering what happened and why !!:eek:

any core ..by itself is worthless..including balsa..take a piece and "whack" it on the side of your workbench and see what happens.

Now skin both sides of it in glass and try it.

do the same with foam and c/f and get back to me with the results.

[Brabender]

Corematt in the topsides is ok and just about every powerboat builder uses it to gain a little more stiffness . Just dont use it in the bottom anywhere !!! :thumbsup:

So this looks ok to you

Also with regard to Kevlar Carbon Lam

Doesnt Kevlar have a life expectectancy?
Also Carbon difficult to Repair?

[tunnels]

Gorilla read it right..kevlar,kevlar, carbon/f, core,carbon/f,carbon/f

That was the thought of using coremat in the first place..to gain thickness..I don't care about what the strength of the core is.thats what the carbons for.

Kevlar is going down first because of the impact resistance, then the carbon for strength.

Wood.....is totaly out of the question for me anyway.



"Kevlar is going down first because of the impact resistance, then the carbon for strength."

Need to take a step backwards and sit and think about whats been written. :confused:
Impact! but from what ? impact as in hitting a rock or hitting a log ? or Water impact from waves big or small ?
Theres are two completely differnate kinds of impact resistance !!:rolleyes:

Carbon for strength . How do you interpret the strenght of the carbon on the inside laminates what is it doing to give it strenght ??
Point remember here is carbon has no streach :leaving:

[tunnels]

any core ..by itself is worthless..including balsa..take a piece and "whack" it on the side of your workbench and see what happens.

Now skin both sides of it in glass and try it.

do the same with foam and c/f and get back to me with the results.

How many boats have you repaired over the years ? How many boats have you made ? reguardless of size , power of sail !
How many lives have depended on the work you have done to come home safely every day ,many times a day in conditions that life savers get seriously hurt in?. :confused:
Do you check your tyre pressure on your car by just kicking the tyres ?
Is wacking any kind of core on the corner of a bench the official cerified test done by the laboritory:eek:
She'll be right mate !! we have the best coast guard service in the world just make sure your boats a bright color so they can find ya !!:cheers:

[mrconcrete]

"Kevlar is going down first because of the impact resistance, then the carbon for strength."

Need to take a step backwards and sit and think about whats been written. :confused:
Impact! but from what ? impact as in hitting a rock or hitting a log ? or Water impact from waves big or small ?
Theres are two completely differnate kinds of impact resistance !!:rolleyes:

Carbon for strength . How do you interpret the strenght of the carbon on the inside laminates what is it doing to give it strenght ??
Point remember here is carbon has no streach :leaving:

Because that is the best method for the materials that I am using.

And thats 100 times better than the kids at the factory built them 30 years ago.

With that being said, don't you think it will work just fine?

[mrconcrete]

How many boats have you repaired over the years ? How many boats have you made ? reguardless of size , power of sail !
How many lives have depended on the work you have done to come home safely every day ,many times a day in conditions that life savers get seriously hurt in?. :confused:
Do you check your tyre pressure on your car by just kicking the tyres ?
Is wacking any kind of core on the corner of a bench the official cerified test done by the laboritory:eek:
She'll be right mate !! we have the best coast guard service in the world just make sure your boats a bright color so they can find ya !!:cheers:

Go read this thread and get back to me..
http://www.yellowbullet.com/forum/showthread.php?t=197083
I drag race..some of the fastest cars in the USA have my fingerprints all over them.

Boats are just a hobbie.....BUT...I figure I would take my skills that I have accumulated over the years and apply it to the boat I once owned as a kid.

Anytime you want to match your engineering skills I'm ready.

What record(s) if any do you hold again?

Sory to be blunt but thats the vibe I am getting

Bill Diehl

[tunnels]

Because that is the best method for the materials that I am using.

And thats 100 times better than the kids at the factory built them 30 years ago.

With that being said, don't you think it will work just fine?

I Know what you are saying and yes what was used years ago has stood the test of time reguardless of there workmanship of the times and the way they were made .
Since the drift (slowly )has been to trying to save weigth and make things go faster than they were ever designed to go and use materials that had never even been thought of when the boat was first build , the repair and re-strengthing thing is a major problem . Dont get me wrong theres many ways of doing certion jobs but its the unsuccessful ones that everyone remembers .
What i have learned over the years of messing about in boats i try to pass on to others , I travel to lots of places to training staff and showing companies what works and what they are doing wrong .
many things have changed but the problems have stayed the same as we had 25 years ago . Theres a wealth of knowledge and exsperiance out there but finding it is not easy . Every one has a story to tell and most stories have things we should learn from but it never happens .
Everything i write about on this site is from what i have seen and done and i know what works and what dosent ! Everything has it limitations and what it can be used for as well as what it shouldnt be used for !!
There always a miss understanding factor that you have to be careful of i have found as well !
:cheers::D:thumbsup::rolleyes:;)

[mrconcrete]

I Know what you are saying and yes what was used years ago has stood the test of time reguardless of there workmanship of the times and the way they were made .
Since the drift (slowly )has been to trying to save weigth and make things go faster than they were ever designed to go and use materials that had never even been thought of when the boat was first build , the repair and re-strengthing thing is a major problem . Dont get me wrong theres many ways of doing certion jobs but its the unsuccessful ones that everyone remembers .
What i have learned over the years of messing about in boats i try to pass on to others , I travel to lots of places to training staff and showing companies what works and what they are doing wrong .
many things have changed but the problems have stayed the same as we had 25 years ago . Theres a wealth of knowledge and exsperiance out there but finding it is not easy . Every one has a story to tell and most stories have things we should learn from but it never happens .
Everything i write about on this site is from what i have seen and done and i know what works and what dosent ! Everything has it limitations and what it can be used for as well as what it shouldnt be used for !!
There always a miss understanding factor that you have to be careful of i have found as well !
:cheers::D:thumbsup::rolleyes:;)

Thanks....Thats why I posted..I want the pros and cons

[Riverman]

Knowledge about building cars does not translate to boats. Aircraft yes but not cars. Listen to the knowledge here and build it right and light. Exotic fabrics are not needed.

Think of the core as the web of a I-beam and the inner an outer skins as the flanges. The deeper the web the greater the resistance to bending - same with core - the thicker the core the better.

Wood (balsa) works fine, lots of pros still use it. It will last if it is installed and encapsulated properly. :thumbsup:

[tunnels]

Knowledge about building cars does not translate to boats. Aircraft yes but not cars. Listen to the knowledge here and build it right and light. Exotic fabrics are not needed.

Think of the core as the web of a I-beam and the inner an outer skins as the flanges. The deeper the web the greater the resistance to bending - same with core - the thicker the core the better.

Wood (balsa) works fine, lots of pros still use it. It will last if it is installed and encapsulated properly. :thumbsup:


Thank you Riverman !!:cheers:

The mixing of materials is not a good thing specialy kevlar,and carbon as well as glass that the hull was origanlly made from .
Cores are another touchy subject as you can see !

Simple is best always ! :thumbsup:

[tunnels]

Someone some where is going to ask why no stringers ! any one know why ?? Anyone what to take a guess??:confused:

No takers ! - OK so i'll will answer the question anyway .
The bottom of hulls need to move ! no i hear you say , yes i say it should be able to move !! and you would be amazed at how much some hulls move up and down , the faster you go the more it moves and the quicker it moves .
This movment helps absorb shock loadings such as hitting waves at speed !.
Wham and the boat goes upwards in a big hurry , During that wham the bottom will have absorbed a good part of the shock before the rest of the boat heads for the sky . Its this micro second of shock thats the killer!!
loads on the whole bottom of the hull are horrendous.
This is where poor workmanship begings to show up .
Poor choice of materials as thing begin to break and tear apart .
If you have a mixture of materilas such as kevlar and carbon then you have even more problems because you will have a harder riding boat and the carbon is trying very hard to do what it does best NOT STREACH and hold the panel ridged .
If you have stringers as well then they have divided the panel size into even smaller areas and makes the boat even harder riding and the loads on the carbon even higher .

Lets back up a little and make a total glass lay up !
Now have a material that will streach and allow the bottom to bend and absorb shock plus recover very quickly hence the uindirectional on the very inside of the layup .
The angle that the uni glass strands runs at is critical to make the bottom stiff , the shorter the strands of glass the less streach ,the stiffer the panel will be ! make sense ?
In this case all the glass is working together because we have simular materials all working with simular charictoristics !!.
If you were to add a layer of carbon as the inside layup then all the stress is thrown directly onto the carbon layer and it wont be to long before something started to give , the ride in the boat would be very hard !!
Adding a stringer could be a advantage but the placement and the size would have to be thought out carefully . Its not the width thats the problem its the height! The higher the less bend so the stronger the top edge of the stringer has to be or as the hull loads and starts to bend the stringer is trying to stop that bend not only in a localised place on the hull but over the total length of the stringer and so it to has huge loads imposed on it in differant places .
Personally i would leave the stringer out and get a slightly softer ride and a hull that would take more shock loading spread over a bigger area and hence a more duable hull .

A good way to demonstrate the movement between the top and bottom surfaces of a laminate is to use a thick telephone book and lay it flat slightly over the edge of a table , grip the two edges tight and the bend the book over the edge of the table . See how far the upper cover of the book moves ! Same applys to the glass layers in the hull The tighter you grip the book the harder it is to bend over the edge , Once you have bent the book still holding tight try to laythe book flat again, see what happens to the pages inside , they will have separate from each other , This is why you need a good core one the does not shear , Balsa !!

This subject could could go no for hours !,so if there are still any questions please ask!:rolleyes:
:cheers:

[Brabender]

Tunnels very interesting

PS I think I may have been on one of your projects last winter
Maritani X in the Bahamas. Was built in New Zealand, Know it?

[afr]

tunnel none of these guys are fiberglass engineers dude there just workers and back yard hobbiest
you know what im sayin
no offence

[commuter boats]

Someone some where is going to ask why no stringers ! any one know why ?? Anyone what to take a guess??:confused:

No takers ! - OK so i'll will answer the question anyway .
The bottom of hulls need to move ! no i hear you say , yes i say it should be able to move !! and you would be amazed at how much some hulls move up and down , the faster you go the more it moves and the quicker it moves .
This movment helps absorb shock loadings such as hitting waves at speed !.
Wham and the boat goes upwards in a big hurry , During that wham the bottom will have absorbed a good part of the shock before the rest of the boat heads for the sky . Its this micro second of shock thats the killer!!
loads on the whole bottom of the hull are horrendous.
This is where poor workmanship begings to show up .
Poor choice of materials as thing begin to break and tear apart .
If you have a mixture of materilas such as kevlar and carbon then you have even more problems because you will have a harder riding boat and the carbon is trying very hard to do what it does best NOT STREACH and hold the panel ridged .
If you have stringers as well then they have divided the panel size into even smaller areas and makes the boat even harder riding and the loads on the carbon even higher .

Lets back up a little and make a total glass lay up !
Now have a material that will streach and allow the bottom to bend and absorb shock plus recover very quickly hence the uindirectional on the very inside of the layup .
The angle that the uni glass strands runs at is critical to make the bottom stiff , the shorter the strands of glass the less streach ,the stiffer the panel will be ! make sense ?
In this case all the glass is working together because we have simular materials all working with simular charictoristics !!.
If you were to add a layer of carbon as the inside layup then all the stress is thrown directly onto the carbon layer and it wont be to long before something started to give , the ride in the boat would be very hard !!
Adding a stringer could be a advantage but the placement and the size would have to be thought out carefully . Its not the width thats the problem its the height! The higher the less bend so the stronger the top edge of the stringer has to be or as the hull loads and starts to bend the stringer is trying to stop that bend not only in a localised place on the hull but over the total length of the stringer and so it to has huge loads imposed on it in differant places .
Personally i would leave the stringer out and get a slightly softer ride and a hull that would take more shock loading spread over a bigger area and hence a more duable hull .

A good way to demonstrate the movement between the top and bottom surfaces of a laminate is to use a thick telephone book and lay it flat slightly over the edge of a table , grip the two edges tight and the bend the book over the edge of the table . See how far the upper cover of the book moves ! Same applys to the glass layers in the hull The tighter you grip the book the harder it is to bend over the edge , Once you have bent the book still holding tight try to laythe book flat again, see what happens to the pages inside , they will have separate from each other , This is why you need a good core one the does not shear , Balsa !!

This subject could could go no for hours !,so if there are still any questions please ask!:rolleyes:
:cheers:

What planet did you step off from !! :confused:I think you are a bit to carried away with all your mumbo jumbo and need to simply get back to plain simple basics . :eek:


Grass roots and simple methods are what it all about when it gets confussing then you end up with problems and things falling apart . workmanship at the end of the day is where more that 80% of the problems stem from . I have traveled to differant countries to work and teach and seen the same problems over and over again , it never changes . :D


Yeah! think and do the job properly ,Take the next step and use vinylester resins to doyour repairs with ,makes it just that little better than using polyester . :thumbsup: :rolleyes: :D KEEP it simple !! its not rocket science to wet out fibregalss with catalysed resin and you dont need a engineering degree ! its simple common sense and dosent take a university degree . Come on think simple !!!!
OK:confused:

[tunnels]

Sorry !!!! get a little carried away at times . :eek:
If you see something thats damaged from just everyday use then you have to ask your self why and how did this happen .
If you cant visulise what would make this happen then you will never know how to prevent it from happening again ! right ?.

Over night iv'e thought about why a lot of the Balsa cores in the boats you guys repair are 1/2" and not 3/4" like i would exspect . Its helps to make the hull move a little and gives a slightly softer ride combined with the shape of being slightly concaved from chine to keel , the age old philosaphy shape =strength Without added weight !

Sorry for thinking ! i will tie my fingers together so i cant type anymore :(

[afr]

no big deal tunnels i know what your sayin
but you should have seen some of these boats you would have never thought they would have made it threw there first sea trial
its all good dont worry about it

[tunnels]

I love what i do ! i always like to study why things happen the way they do and not just listen to idle speculation from tie wearing narrow minded surposed experts . I have worked with so many really clever guys over the years and seen so many good ways of doing simple jobs !
Iv'e also worked with a bunch of idiots as well that only go to work to eat there lunch and get away from there Mrs and the kids each day and never learned a thing and never will .
I was even working in the company here in nz when Young America Yacht was repaired after snapping in half , This was the high end of a major failure and was a combination of things not just one . I spend hours going through all the damaged centre part of the boat silently asking why . as i said it was a combination of things and wasnt the first or the last as the Australians lost there boat the same way as did a coule of others . I was privelaged to meet and talk to the guys that worked doing the repair work from Geotz boat builders .
I was thrown in a surf life saving boat and taken out into the huge surf at our west coast beachs to see first hand what they did with there boats that used to fall apart and break just at the wrong time . High modulas had spec'd the special HD lay up that was unbreakable according to there engineer . It was quite simple to sort out really the boats had to be built flexable and go with the flow so to speak .I built a first boat to how i thought it should be, came out a lot lighter and using just one type of glass off the shelf and ordinary polyester resin with a heap of simple common sense ,from then on not one boat ever got dammaged or broke and the company has never changed that way of making there boats in the past 10 years .
The stories of learning goes on and on and i hope will never stop till i cant move any more . :D

[CUDA]

I understand the reasons you like flex, but on the other hand this is H P boat site and many of us don't give a $hit about stiff ride . In my mind the stiffer the better in the pad / running surface area. Yes I like CF in the pad area / like a ROCK
Why because it is faster. I have boat raced since 1979 and started working on blueprinting pads / redesign pads since 77 and flex in the running surface has never been a desire. of mine .
You are a very smart man , I bet you work on lots of off shore type boats, that go through a lot more stress than we put our boats through, Most of us run 18' to 21' outboards that weigh 400 lb to 900 lb.bare hull ,with outboard jack plates 4" to 14" . When we are going 80-100+ we have about 10" to 18" touching the water, we don't want flex for a soft ride and we are NOT going out in big waves , because our boats were not designed for such a purpose. Lots of us drag race where one tenth of a second is about 20 feet in a 1/4 mile race .
PS the picture below is a Plug I'm finishing up , picture is four mo. old , lot closer now ( always can find something wrong)

Years ago APBA sent me instructions on how they wished safety capsules be constructed. They recommended kevlar on the out side CF underneath one inch core with more CF.

[tunnels]

I understand the reasons you like flex, but on the other hand this is H P boat site and many of us don't give a $hit about stiff ride . In my mind the stiffer the better in the pad / running surface area. Yes I like CF in the pad area / like a ROCK
Why because it is faster. I have boat raced since 1979 and started working on blueprinting pads / redesign pads since 77 and flex in the running surface has never been a desire. of mine .
You are a very smart man , I bet you work on lots of off shore type boats, that go through a lot more stress than we put our boats through, Most of us run 18' to 21' outboards that weigh 400 lb to 900 lb.bare hull ,with outboard jack plates 4" to 14" . When we are going 80-100+ we have about 10" to 18" touching the water, we don't want flex for a soft ride and we are NOT going out in big waves , because our boats were not designed for such a purpose. Lots of us drag race where one tenth of a second is about 20 feet in a 1/4 mile race .
PS the picture below is a Plug I'm finishing up , picture is four mo. old , lot closer now ( always can find something wrong)

Years ago APBA sent me instructions on how they wished safety capsules be constructed. They recommended kevlar on the out side CF underneath one inch core with more CF.

Because i worked making Surflife saving boats that were used on our west coast beachs for the absolutely exstreme conditions where boat drives broke before the boats did i learned a lot about making laminates that distruct progressively and not just go bang and its over !.
This is really interesting to play with , No one know any thing about building boats to do this and its really quite easy and simple when you understand the materials you want to use and there capabilities .
Have seen hi tech parts made from exotic materials like Carbon /kevlar / with nomex honeycomb core last as long as it takes to get over the first big wave and roll back to the beach in a dozen bits with the motor hanging on by just the Stainless steel safety lanyard .

For what you are making i would make the boat real light and use One Triaxle
+ core(balsa )
+ triaxle
+unimatt and
internal stiffeners made from Double bias and unidirectional glass , using Vinylester resin .
Trick is how you go about using those materials thats the key to it all . ASK any engineer he would shudder and shake his head in disbelief and laugh! maybe .

The triaxle id be looking for is a special that you cant just go buy any old type of triaxle off the shelf .
The uni is just uni matt but its the oriantation of the strands thats the important bit .
Construction of the stringers the same !,it how you design and make them thats the trick bit .
How long is the boat and what sort of Hp and speeds are you looking at ?
I like the rolled over Flanges but i feel they could have been a little more aerodynamicly shaped to get a better air flow from the hull sides up and over the gunwhale onto the deck without to much turbulance .
I hope you remember that boats travelling over 60 mph are quickly changing from Hydro-dynamics to aero-dynamics and the air lift and effects of are crucial because it is wanting to fly!!
Id like to see more of what you are doing ! this is really interesting .
Tunnels boats are my forte hence the name "TUNNELS" !
:thumbsup:
Have you heard the exspression SHAPE = STRENGTH WITHOUT ADDING WEIGHT !
Something to think about on a cold winters night !

[conmax]

I don't know much about lite weight boat building, but at least one west coast cat manufacturer said they were starting a complete new build, deck and hull, using carbon kevlar rolls and a new resin. Easier to work with than epoxy and just as strong, this resin doesn't require the typical mat layer to absorb the resin. Expected to save 200-300 lbs on a 27-29 ft cat. I will try to get the name of this resin, but it is apparently already used by some other high performance builders.

[tunnels]

I don't know much about lite weight boat building, but at least one west coast cat manufacturer said they were starting a complete new build, deck and hull, using carbon kevlar rolls and a new resin. Easier to work with than epoxy and just as strong, this resin doesn't require the typical mat layer to absorb the resin. Expected to save 200-300 lbs on a 27-29 ft cat. I will try to get the name of this resin, but it is apparently already used by some other high performance builders.

OK they will be using Vinylester resin for sure ! yes its as good as an epoxy but much easier to use !,
Carbon and Kevlar or two completely opposite materials! , Carbon has no stretch at all and is stiff as!! Kevlar is completely the opposite and will stretch so much it can pull out of the resin that's holding it !, But Kevlar gets used in combination so when the carbon fails and breaks the Kevlar holds it together !
Make sense ??
In all my years I would never use either carbon or Kevlar, Only the vinylester resin and glass that's all!! its a well known fact that mixing different materials is a absolute no no and if its something new then I say wait and see what happens ! this has all been done before many years ago and caused problems ! seems some people never learn from past experience's!!! .
What they doing is not new ! I would never buy and first of anything and if its taken all this time to make a change to better or different materials then they are pretty slow learners .

[conmax]

Since they are using rolls of carbon fibre with kevlar in striped strands, this allows the flex as well as the stiffness you mentioned. I think it is one carbon one kevlar alternating in the roll. I imagine there is some adhesive or pressure applied in the process that hold the strips in place before resin is added. It must do a pretty good job of initial bonding because I could not tear the pieces apart by hand.

The resin may be vinly ester, but I believe that is what they have been using for a long time. This is supposed to be some new resin, stronger and lighter at the layup level. I believe that they are using 2 layers of CF/kevlar with this new resin and no absorption mat to contain the resin. There is likely a fiberglass layer w/o the mat attached. I will have to verify the resin with the boat company owner. I don't think any of this is that new and certainly not experimental. They have used this resin on various molded parts for quite some time, but this next build will be the first complete boat to use it. The expectation is about 10% weight reduction on a bare 28' cat.

[tunnels]

Since they are using rolls of carbon fibre with kevlar in striped strands, this allows the flex as well as the stiffness you mentioned. I think it is one carbon one kevlar alternating in the roll. I imagine there is some adhesive or pressure applied in the process that hold the strips in place before resin is added. It must do a pretty good job of initial bonding because I could not tear the pieces apart by hand.

The resin may be vinly ester, but I believe that is what they have been using for a long time. This is supposed to be some new resin, stronger and lighter at the layup level. I believe that they are using 2 layers of CF/kevlar with this new resin and no absorption mat to contain the resin. There is likely a fiberglass layer w/o the mat attached. I will have to verify the resin with the boat company owner. I don't think any of this is that new and certainly not experimental. They have used this resin on various molded parts for quite some time, but this next build will be the first complete boat to use it. The expectation is about 10% weight reduction on a bare 28' cat.

A 10% weight reduction even using glass is very easy to achieve specially with a deck included ! But it sound interesting and would like to know more ! there are many types of resins in each of the vinylester and polyester ranges !, Even epoxy there's a long list !

[tunnels]

The orientation of the various layers of the different fabrics and there placement within the laminate glass stack is the secret to saving weight and reducing the amount of materials used and having a good understanding of how all these things work ! , And no you don't have to be a composite engineer ! this is simple everyday laminating knowledge that most any good laminator worth his weight in salt should understand and know these things !.
Chopped strand in thin layers is necessary in between layers of each of the fabrics to help strengthen the resin layers with glass ! these days very light glass without binder is stitched to most fabrics you buy so these are excellent to use with polyester ,Vinylester and even epoxy !. In general what ever you use to build with is what you should use all way through to the end That way everything works in unison and don't have different materials with completely different properties fighting with each other !, like I pointed out Kevlar is used within some fabrics to hold the carbon together if it self destructs ! So what does that tell you ?? Using those two together is old hat ! many things have changed and great lessons in the use of different materials have been learned since those early days,
Look back at the earlier Americas cup racing days not so far back history ! Now how many of these boats have structural failures these days ? even the aircraft industry knows better than to mix materials ! take note !!

[conmax]

i found out more about this new, magical resin. it is not polyester and is claimed to be safer, stronger and lighter than epxoy w/o the print through issues. this resin is urethane acraylate and is made by Scott Bader in the UK. Branded Crestobal 1250lv, it promises 30-50% weight reduction. is was designed for CF so should be great with the CF/Kevlar rolls. The first hull in the US to be built using this resin is 28' fun deck by a west coast boat mfg. it is expected to save 25% or about 500lbs on the hull alone. the hull is in the mold now and should be weighed by the end of next week. if the projection are true, the resin will save more weight than using CF/Kevlar alone over glass with balsa and mat.
OK they will be using Vinylester resin for sure ! yes its as good as an epoxy but much easier to use !,
Carbon and Kevlar or two completely opposite materials! , Carbon has no stretch at all and is stiff as!! Kevlar is completely the opposite and will stretch so much it can pull out of the resin that's holding it !, But Kevlar gets used in combination so when the carbon fails and breaks the Kevlar holds it together !
Make sense ??
In all my years I would never use either carbon or Kevlar, Only the vinylester resin and glass that's all!! its a well known fact that mixing different materials is a absolute no no and if its something new then I say wait and see what happens ! this has all been done before many years ago and caused problems ! seems some people never learn from past experience's!!! .
What they doing is not new ! I would never buy and first of anything and if its taken all this time to make a change to better or different materials then they are pretty slow learners .

[tunnels]

i found out more about this new, magical resin. it is not polyester and is claimed to be safer, stronger and lighter than epxoy w/o the print through issues. this resin is urethane acraylate and is made by Scott Bader in the UK. Branded Crestobal 1250lv, it promises 30-50% weight reduction. is was designed for CF so should be great with the CF/Kevlar rolls. The first hull in the US to be built using this resin is 28' fun deck by a west coast boat mfg. it is expected to save 25% or about 500lbs on the hull alone. the hull is in the mold now and should be weighed by the end of next week. if the projection are true, the resin will save more weight than using CF/Kevlar alone over glass with balsa and mat.

Sure sound impressive that's for sure and thank you for the follow up Scott Bader make some nice resins and in the past have used there vinyl-esters ! keep us posted as the project progresses please !!! SURE IS INTERESTING !!

[Da Bull]

WOW! Very long and informitive thread. Two questions: Did mrconcrete finish his boat and with what materials? Also after reading this intire thread i saw where many times the use of carbonn fiber and kevlar was layered. What about a carbon/kevlar weave? I saw a roll of this a while back at Triad Boats. Wouldn`t this be better than layered?

[conmax]

I have only seen rolls of CF/Kevlar at our local custom boat builders. It is a weave of CF interspersed with a weave of Kelsey fibers. The CF is black and stiff wearas the Kevlar is flexible and yellowish. It can be laid up just told of glass cloth at about 50x the cost.

[tunnels]

I have only seen rolls of CF/Kevlar at our local custom boat builders. It is a weave of CF interspersed with a weave of Kelsey fibers. The CF is black and stiff wearas the Kevlar is flexible and yellowish. It can be laid up just told of glass cloth at about 50x the cost.

AAH but are you getting 50x the satisfaction by using these supposed magic materials ??
The materials you speak Of along with a few others of equal interest splashed into the boating manufacturing industry in the 1980s/90s and were widely used for a while till it was realized guys weren't really getting what they were looking for in the way of lighter boats with better more robust trouble free boating !and the cost finally sunk in to achieve what ??
One very big problem with making boats lighter and stronger is it has to be in conjunction with a new design of hull !!When using a older designed boat hull shape suddenly there is a whole new bunch of problems boats don't ride well and handle even worse because they had weight before sure they go faster but can be rougher riding and because they are stronger guys drive them harder so add all things together is it really worth the excise ?? could fit water ballast tanks !!.
Don't get me wrong I am all for change and making things better but it should be a whole new package deal not a half hearted effort !

[conmax]

In examples that I have seen, the CF/Kevlar are options on existing designs to reduce weight and/or increase strength. They are priced in the 20-30k range for a 29 ' tunnel and can save 400lbs. Nothing really new here, just lots of cost to save weight critical to the new 400 verados.

The new resin is separate from the CF options, lower cost with similar weight savings.

[tunnels]

At long last it being realized carbon breaks and it splinters to easy and now they starting to make some that's a little more flexible and doesn't splinter !
Have never found any use for carbon fiber in anything have had to replace and repair so many times for things that have broken its not funny and anyway its to highly over rated ! S glass and E glass is much better choice !!

[conmax]

Since CF is so brittle, the applications I have seen for boats use a CF/Kevlar rolls with the fibers alternated, giving the flexibility of Kevlar to the stiff, brittle CF. The new resin, made by Scott Bader in the UK, is urethane based and was designed to used with CF. They have built many CF based auto racing bodies with this resin and claim 40% mass reduction. They even built some large military boat and achieved similar savings while adding strength. Purported to be better than epoxy w/o the handling toxicity and print through. I will know more once my 28' cat is built using this resin, CF/Kevlar, foam and Airex penske.

[tunnels]

Since CF is so brittle, the applications I have seen for boats use a CF/Kevlar rolls with the fibers alternated, giving the flexibility of Kevlar to the stiff, brittle CF. The new resin, made by Scott Bader in the UK, is urethane based and was designed to used with CF. They have built many CF based auto racing bodies with this resin and claim 40% mass reduction. They even built some large military boat and achieved similar savings while adding strength. Purported to be better than epoxy w/o the handling toxicity and print through. I will know more once my 28' cat is built using this resin, CF/Kevlar, foam and Airex penske.

Urethane is a pretty awesome product specially in adhesives !! AS a resin sure as hell will be different !!
Have a wonderful xmas and a better new year !!

[Davidlake]

Tunnels, I have been reading this thread and am a bit overwhelmed with the many paths boat builders are using to make their products. You stated that CF is too brittle for boat hull construction. I was having a conversation with an almost world champion F1H2O boat driver (soon to be, I hope!)who was telling me that his and the other F1 boats were almost all CF, with the exception of the capsule. I questioned him, based upon what I know about CF being brittle and he said, no, they are definitely CF. Your thoughts on this? I know that my Skater has Kevlar layup where the hull is capped and at the bulkhead to hull juncture. That makes scene to me! Skater also offers a "CF layup" option, but I do not know where it is used. Your thoughts are appreciated.

[Da Bull]

AAH but are you getting 50x the satisfaction by using these supposed magic materials ??
The materials you speak Of along with a few others of equal interest splashed into the boating manufacturing industry in the 1980s/90s and were widely used for a while till it was realized guys weren't really getting what they were looking for in the way of lighter boats with better more robust trouble free boating !and the cost finally sunk in to achieve what ??
One very big problem with making boats lighter and stronger is it has to be in conjunction with a new design of hull !!When using a older designed boat hull shape suddenly there is a whole new bunch of problems boats don't ride well and handle even worse because they had weight before sure they go faster but can be rougher riding and because they are stronger guys drive them harder so add all things together is it really worth the excise ?? could fit water ballast tanks !!.
Don't get me wrong I am all for change and making things better but it should be a whole new package deal not a half hearted effort !


Not looking to dispute your post as you seem to know way more about this stuff than me or the average guy. However just the other day I was watching the Lucas Oil Drag Boat series on TV and they did a shot inside of Brian Sanders Top Fuel Hydro capsule and what did I see but a carbon/kevlar weave on the walls. These guys have a huge budjet and can afford the best of everything so maybe this stuff wasn`t just for the 80`s & 90`s. Looks like they are still using it.

DB

[conmax]

Used on my current build along with foam penske board and new urethane resin, first in the US.

[tunnels]

Not looking to dispute your post as you seem to know way more about this stuff than me or the average guy. However just the other day I was watching the Lucas Oil Drag Boat series on TV and they did a shot inside of Brian Sanders Top Fuel Hydro capsule and what did I see but a carbon/kevlar weave on the walls. These guys have a huge budjet and can afford the best of everything so maybe this stuff wasn`t just for the 80`s & 90`s. Looks like they are still using it.

DB
yip its still used but a lot of research and development has gone on since those early days !, different weaves different percentages of each material even the materials themselves have changed and there are different grades that we never had long ago ! Kevlar and carbon are used together so if one fails the other is there as support ! Hard and brittle Carbon and soft and tough Kevlar so during a crash its a double safe guard .
I have noticed very recently that there are new more flexible grades of carbon that could find there way into the industry ! I haven't seen any test results but maybe Kevlar could get replaced !. Lots happening in the research and development field for aircraft and automotive applications and needs so eventually could find it way into the marine industry as well !!

[Da Bull]

Tunnels you are right about technology. It never stops. New stuff coming out year after year.

DB

[tunnels]

Tunnels you are right about technology. It never stops. New stuff coming out year after year.

DB

Its more like week by week !
The drive is mostly from aviation and the auto industries is the driving force behind most of it !! the marine industry doesn't ever rate a mention in any this, typical !! :eek: