what wood to use???? do i really need marine grade????

[regalman4925]

ity seems from tearing my transom out that the resin sticks just fine lol. how is the marine grade going to rot any different then normal ply?? from what i have figured out it really doesnt matter, if water get sinto the wood it is done so why not just resin the crap out of the wood and seal all spots that could allow water in?? water resistant glue doesnt sell me....

[glassdave]

your transom should be two layers of 3/4 ply with a layer of ounce an a half in between as a binder. You will be fine using a good quality outdoor rated. The biggest factor in the life of the wood is how its installed and making sure ALL thru holes are properly sealed. I have been told that some of the older Bajas did use dimensional lumber for whatever reason. I would not under any circumstance use and non laminated lumber for a structural piece. You will have a far far stronger piece using two layers of 3/4 as opposed to a solid piece of wood.

I have a friend the swears by an outdoor 7 ply Luan type laminate that he uses and he beats the ever loving snot out of his 30 Sleek Enforcer with no problemss after several years. He replaced all the stringers front to back and the transom with it. So far so good. Its about fourty a sheet and the thing i like most is its always nice and straight. Marine ply is better if you can swing the extra cost but, done properly, you'll be fine with outdoor rated stuff.

I guess i look at it this way. I've personally done tons of structural repairs with standard outdoor rated and none have come back. My ScarabIII was marine rated and pretty much every piece of wood in that boat de lammed and had to be replaced. It all comes down to the installation. The Scarab had tons of exposed wood every place a hole was cut, that killed it. On the other side of the coin i have a 1984 35 Cig in the shop that has 100% original wood in unbelievable shape but every edge is wrapped and all through holes have been properly sealed. prep prep prep is the key.

[regalman4925]

thanks glassdave, i am in total agrement with you on the fact that it is not so much the wood but more of how you prep it. my transom is actually 2 pieces of 3/4 and a layer of 1/2 making it 2" if i recall correctly. i still think dimensional lumber will work fine as long as it is all very well laminated. i had one shop tell me that if the factory used it then there may have been a reason in the engineering for it, not sure how true that is but like we said before, the last stuff lasted 20 years and i think it would have lasted longer if the retard that left it out for 3 years in midwest weather had thrown a cover over it! another point was brought up that it can curl, the original stuff did not curl at all, it was as strait and square, just a little rotted. here is a experement for everyone, lets take a piece of both normal plywood and a piece of marine grade plywood and lamintate them, really well so there is no chance of water getting in, let is sit outside in a bucket of water for the next year or 5 or 10 or ? and lets see what happens, my guess is they will both hold up just as long?? so again i ask why marine grade? i do understand that it is a little higher qualty but is it going to make a noticible difference besides on my wallet?

should i even bring up the resin topic? epoxy vs. polyester? both shops in town said they use polyeter, one had been doing work for 10 years and the other nearly 25 and claimed to have no issues...

[pasquesi]

Originally Posted by daredevil

The diffrents is not just only the voids,, its the marinegrade is a non oil plywood verses reg. plywood so the resin can bond to it better and the glue used for the marine ply is also water resistant where the regular one is not,,,the marine ply will NOT rot as the regular one either.

You are incorrect. Marine grade can rot just as easily as standard exterior grade. The ONLY difference is the tolerance for the allowable voids. Standard exterior grade A/C or B/C will be just as effective as any marine grade.

[rchevelle71]

Originally Posted by regalman4925

thanks glassdave, i am in total agrement with you on the fact that it is not so much the wood but more of how you prep it. my transom is actually 2 pieces of 3/4 and a layer of 1/2 making it 2" if i recall correctly. i still think dimensional lumber will work fine as long as it is all very well laminated. i had one shop tell me that if the factory used it then there may have been a reason in the engineering for it, not sure how true that is but like we said before, the last stuff lasted 20 years and i think it would have lasted longer if the retard that left it out for 3 years in midwest weather had thrown a cover over it! another point was brought up that it can curl, the original stuff did not curl at all, it was as strait and square, just a little rotted. here is a experement for everyone, lets take a piece of both normal plywood and a piece of marine grade plywood and lamintate them, really well so there is no chance of water getting in, let is sit outside in a bucket of water for the next year or 5 or 10 or ? and lets see what happens, my guess is they will both hold up just as long?? so again i ask why marine grade? i do understand that it is a little higher qualty but is it going to make a noticible difference besides on my wallet?

should i even bring up the resin topic? epoxy vs. polyester? both shops in town said they use polyeter, one had been doing work for 10 years and the other nearly 25 and claimed to have no issues...

I would not use dimensional lumber, it is not nearly as strong with the grain going all in one direction as laminated ply, if you crack ply due to the grain, you have several other layers with opposing grains to back you up, if you crack a 2x6 it will splinter like a shattered baseball bat. Even if it doesnt splinter on the first shot, it will get worse every time you pund the bottom of the boat over a wake. There is a reason 99% of Boat manufactures use it, and since we have decided that regular Exterior grade ply is OK, the price is not really a problem.

[regalman4925]

i cant say that i disagree with that. on the otherhand i am thinking i can still save a good portion of the wood in the cabin area, if this is still left as 2x10 do i want to use plywood? if i tear it out all the way to the front like most would recomend then i am going to have a even bigger project! lol i guess it goes back to the point of what came out of it? the old stuff did not crack and i am in the midwest so i will never see crazy wake like allot of people on the site do, it is usually calm and most boats around are under 25 feet and since we are on the river 99.9% of the time is doesnt getr rough, not sure if we can look at that as a reason to or not to??

[regalman4925]

ok i will scrap the boat and stay home then!

[pasquesi]

Originally Posted by regalman4925

i cant say that i disagree with that. on the otherhand i am thinking i can still save a good portion of the wood in the cabin area, if this is still left as 2x10 do i want to use plywood? if i tear it out all the way to the front like most would recomend then i am going to have a even bigger project! lol i guess it goes back to the point of what came out of it? the old stuff did not crack and i am in the midwest so i will never see crazy wake like allot of people on the site do, it is usually calm and most boats around are under 25 feet and since we are on the river 99.9% of the time is doesnt getr rough, not sure if we can look at that as a reason to or not to??

You could use Microlam material. It's a structural dimensional material made by pressing thousands of strands of lumber together bonded with exterior glue. It comes in 1 7/8" thickness, and widths from 9 1/2" up to and beyond 24". Since you will be encapsulationg it in resin anyway, that would be the stongest product I know of in that dimension.

[pasquesi]

Originally Posted by daredevil

If u whant to save money ( 500 bucks) then don't go boating !

That's a helpful comment.

[northernoffshore]

marine grade ply has more laminates inn it . count the side of it, the layers 1/2 shold be 7,3/4 about 9 layers