glass lay up information for boat speed boat

[elegant bass]

hi need some info on how to calculate glass thickness on speed boat do have the mould to build the boat but don't have the glass lay up information if any one would shed some light on this project of mine i`ll appreciate your help.
raffi
17ft x 6ft beam don`t have any photos yet will post photos asap thanks in advance

[Cobra1racer]

Well if it's a "speed boat" are you going to race it?? Are you going to beat it to death on big waves? Knowing what you plan on doing with it will determine the lay-up that you will need. A light boat in big waves SUCKS and a heavy boat racing will SUCK as well.

[tunnels]

Hi
Be carefull and choose the types of glass you use .
Woven Roving is tough but uses more resin to wet out ,the same weight of a fabric will use less resin and make a stiffer panel .
When laying up a power boat hull start laying glass from the bow and go up the transom .
Joins should have a minimum over lap of 3 inches any where .
Allways overlap glass into the chine and into the keel so it doubles up . The keel is always the first part of a hull to get grounded and the more glass there the better . The chine joins should be from the bottom of the hull , then the top sides coming down over the top and lapping 2 to 3 inches .
The dirrection of Overlaps in glass for hi speed boats is very important because if the skin gets a punchure from hitting a partly submerged object at speed and the water pressure gets in it can and will hydralic layers of glass completely off the hull .
Scary stuff specially when you are 20 miles off shore and it happens and you look out the back of the boat and see a sheet of glass sinking into the deepths .
Hell! how much is still left are you first thoughts and can i get home or even just to dry land again some where .

[hsbob]

you'll have to do a web search. i see some fininate element SW program based on glass parameters but did write the sites down. the cost was too high for my small repairs. there's a lot of seat of the pants requirement that are based on good experience. its all a matter of how close do you want to go. the marine artectitect [sp] have some site with good data.

[Cobra1racer]

What did he say???????????????????

[Cobra1racer]

You can start at which ever end you want. I always started at the back and went foreward. But one thing is a must. Start in the bottom and work your way up the sides. Why you ask. Well if you do dthe sides first and lean over the wet stuff to get to the dry stuff in the bottom to the center of the mold, you stand a 100 percent chance of getting your tally wacker wet from resin. And BOY DOES IT BURN!! For me 20 CC's of MEK to 3/4 gallon of resin. Wet out the whole side, top to bottom and then come back and roll it out. A good amount of the air was out of it, just from being wet and sitting. And for the transom, never have a seam in it. I always cut a piece for the transom that would over lap the bottom and sides of the other glass. This way you will keep it flat, better for the wood to bond too.

[tunnels]

You can start at which ever end you want. I always started at the back and went foreward. But one thing is a must. Start in the bottom and work your way up the sides. Why you ask. Well if you do dthe sides first and lean over the wet stuff to get to the dry stuff in the bottom to the center of the mold, you stand a 100 percent chance of getting your tally wacker wet from resin. And BOY DOES IT BURN!! For me 20 CC's of MEK to 3/4 gallon of resin. Wet out the whole side, top to bottom and then come back and roll it out. A good amount of the air was out of it, just from being wet and sitting. And for the transom, never have a seam in it. I always cut a piece for the transom that would over lap the bottom and sides of the other glass. This way you will keep it flat, better for the wood to bond too.

Weights and measures
Right you need GOOD ACCURATE scales and a suitable container (glass possibly) FOR CATALYST with CC scales marked on it .
Measure dont guess , so each brew of resin goes off at the same speed as the one before and you have peace of mind that it is going to go to the same hardness as well . Plus you know how much time you have to work with it .
To little catalyst and you have soft resin that will never reach it full hardness , now the other end ,to much and it becomes brittle and wont take the knocks .Check with the supplyer as to the correct catalyst ratios you can safely work in most resin work within 3/4 persent to 1 1/2 persent so the resin will get to its correct hardness.
Get my drift !!DONT GUESS !!!!!.
If you have a problem with the resin at some stage down the track because you are over catalyzing or under catalyzing and you go to the manufacture and if they do a sample test you have no came back and no product warranty .
Aways back i delt with temprature and humididty and keeping you glass dry and your resin at a suitable temprature .
Might be time to refresh these points again in this case .

[elegant bass]

boat is for skiing with family and friends if it ends up heavier hull should i use chop mat or other type of material please specify thanks.
planing on putting two stringer 12mm thick each glass all over + center keel stringer false floor 12mm ply transom3x12mm ply glassed in between each ply. planning on having the hull 8mm thick 12mm transom 6mm sides and top deck is this OK or to light. can i use one type of chop mat or different weight. thanks for all the input.
raffi

[Cobra1racer]

1 1/2 oz mat for the skin, 1708 for the strength. I used some free 3 oz mat once, once is all it took to like 1 1/2 oz. Put extra 1708 in the corners, they take a beating. Buy a roll of mat and a roll of 1708 bi-directional (50") and one drum of resin, and a gallon of MEK. How many colors of gell (5 gallons total) and a five gallon can of acetone. Keep the scraps of mat and bi to tab the deck to the hull.

[elegant bass]

thanks for your information i`m hading to buy all the product you have mentioned i`ll put some pics as i go thanks for all your help.
raffi

[hsbob]

in that case post the picture first. i thought you were designing a new hull. if we can see what your doing the suggestion maybe better.

[elegant bass]

i do have the mould need to go and pick it up from workshop tomorrow i will put some photos of the mould

[elegant bass]

photos of the mould
what you think of the lay up strenght
white gel coat,1layer off 230,1x600 chop strain mat,1xtraxcil 768g,1x600 chop strain mat,2mm core mat,1x600 chop strain mat,
double on chine stringer base and transom.
17mm stringers x3,
transom x3 17mm ply glass in between
12mm floor glass top and bottom.
hp 150hp or 200hp outboard
is this set up be OK any input please

[tunnels]

core mat - dont use any thickness core matt in the bottom !!!.
does any one know what corematt is surposed to be used for ???? .

It found its way into the boating industry through a back door and was never designed for boating.

I have been in the industry since 1972 and it took quite some time for me to find out where and what it was meant to be used for as well . Then i realised why there were failures when it was used in certion applications , one being hull bottoms .

Its not a trick question just interested to know what you think its surposed use is !

Looking forward to this !!

[elegant bass]

core mat is for flat side panels and top deck front part