carbonfiber/kevlar layup

[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" !

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.