sealer for marine plyboard

[Laram51]

Guys

I am in the process of redoing the transom on my 24' Proline.It's one with a single gil bracket I had it done five years ago and did not expect to have it redone so soon. I put together three 1/2 '' marine plyboard and got a thickness of little under 2' after applying matt and roven. I did not use any form of sealer and I am wondering if that's the reason why i did not get a longer life from it. I read about a CPES (clear penetrating epoxy sealer) but it's not available here. Wondering if Thomsons sealer can be used and if it will help in anyway to make the wood last longer. Thanks

 

[Islandlure]

Re: sealer for marine plyboard

After messing around with boats for awhile now, I must say I dont believe anything that you buy at lowes or home depot is suitable for marine use. I think a thin layer for resin would work much better than thompsons, and wont cost much it you have a budget in mind. But this is just my opinion.

 

[Robj]

Re: sealer for marine plyboard

If you are using poly resin dilute with Acetone add about 10 to 15%. Afterwards apply another coat of resin, then gel coat and it should be sealed. Another option would be to use pressure treated plywood, but you must make sure it is very dry before proceeding. I would not use Thomsons water seal on my transom.

Good luck

Rob.

 

[Laram51]

Re: sealer for marine plyboard

I have an experience "fibre glassman" and he says the same thing..he has never used a sealer and is recommending coating with resin as you suggested..I cant remember coating the board the last time..

Thanks for the swift reply guys

 

[Islandlure]

Re: sealer for marine plyboard

I think think that would be the best solution. Good Luck

 

[DillyDally]

Re: sealer for marine plyboard

Check out rotdoctor.com for the CPES stuff and other advice. The West Marine fibreglass application books they sell for $5 are pretty good too.

 

[ondarvr]

Re: sealer for marine plyboard

If it only lasted 5 years then there must have been a great deal water getting to the wood. If you glassed the entire transom and covered all the wood, then the only place for water to get in was from the holes you drilled to mount the bracket or other things. If thats the case, then it will fail again unless all of these holes are sealed when you do it this time so no water can get to the wood.

Just coating bare wood with resin or gel coat will help a little, but polyester resin isn't a great sealer for wood, it can crack and peel off too easily if no glass is used.

 

[gcboat]

Re: sealer for marine plyboard

Little hint on sealing those holes up: Make them a little larger than they need to be. Fill the complete hole with something like Marine Tex, let it cook really good. Then drill the size of hole you need through that. The surrounding wood will be sealed from any water intrusion. Don't give yourself any more than 1/8" on the circumference ( with the Marine Tex ).
Meaning the second hole you drill shouldn't leave any more than 1/8" of material around it.

 

[Laram51]

Re: sealer for marine plyboard

Thanks Ondarvr and GC Boat

Thats exactly what happened. Water came in thru those hole from the bracket.

The 5200 that I used to seal the bracket must have broken down . I am planning to seal the bracket by screwing on a piece of aluminum plating to the inner side of the bracket that rests on the transom before putting it back up .I plan to use 5200 and countersink nuts and bolts. Foam might not be the best to put in there .

Thanks for your suggestions on making the holes wider.

 

[Coors]

Re: sealer for marine plyboard

I don't see 5200 breaking down, unless it was installed against something wet, or rotting, or not cleaned.

 

[Laram51]

Re: sealer for marine plyboard

Guys

It would appear that the water enters the bracket and remains there and this causes the problem. The water finally seeps into the transon and rots the wood. The weight of the motor on the single bracket causes a slight bulge on the outside of the transom..Wondering if some sort of reinforcement could be put in this area while rebuilding the new transom . One way is to replace the bracket and use one with a platform so that the stress could be evenly distributed right across the transom but this could prove expensive.

I am thinking about sealing off the bracket with a 20x15 piece of aluminum sheeting before installing . This is the size of the opening that fits on the transom. This might be more effective than sealing on to the hull itself..Any ideas anyone..

Thanks.

 

[Laram51]

Re: sealer for marine plyboard

Please note...24' Proline with 225 yamaha on single gil bracket.