Using warped plywood for bench seats

jmok1978

Seaman
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Apr 25, 2021
Messages
61
I have a sea king that needs the bench seats replaced. I have some plywood that the prior owner cut to exact size but never got around to finishing them. The plywood has kind of twisted so that it doesn't lay even close to being flat. I can manipulate it by hand to slide into the front and back aluminum rails that holds the seat in place. If I fiberglass the plywood will it still flex enough for me to be able to manipulate it into place and get it installed or will it lose it's flexibility?
 

RaftRat

Seaman Apprentice
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May 14, 2021
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36
I wouldn’t count on it still being flexible enough. I would try to see if I could flex it back into place, and clamp it for a few days. Maybe even flex it past flat and flex it the other way and clamp it there. Then after I got it flat and stable I would glass it. But I would say once you glass it, you’ll have a harder time flexing it to get into place and it will be near impossible to truly have it flat again.
 

Drivewayboater2

Petty Officer 1st Class
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Aug 21, 2019
Messages
334
you could screw it to a straight board on one side… glass the opposite…once cured do the other side. Just a thought. Since you have a template you could just get new plywood… might me less time consuming.
 

jmok1978

Seaman
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Apr 25, 2021
Messages
61
you could screw it to a straight board on one side… glass the opposite…once cured do the other side. Just a thought. Since you have a template you could just get new plywood… might me less time consuming.
Yeah, I think I'll just buy some new plywood instead. Don't want to waste a bunch of fiberglass.
 

RaftRat

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May 14, 2021
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Yeah, I think I'll just buy some new plywood instead. Don't want to waste a bunch of fiberglass.
If buying new is an option, it’s probably the easiest and most time efficient method. Good luck
 

jmok1978

Seaman
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Apr 25, 2021
Messages
61
Last question, should I add a 2x6 under the plywood to reinforce it or will the fiberglass provide enough rigidity? At some point I plan on mounting a swivel seat.
 

RaftRat

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May 14, 2021
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So I’m a big boy, so I doubled my plywood up, and it’s pretty stout now. But I would think you would want some kind of reinforcement
 

RaftRat

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May 14, 2021
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Sorry, I guess I didn’t really answer your question, I would think 2x6 would be good, but I think you could get by with less. And if you do reinforce with wood, I would glue it and screw it.
 

jmok1978

Seaman
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Apr 25, 2021
Messages
61
Sorry, I guess I didn’t really answer your question, I would think 2x6 would be good, but I think you could get by with less. And if you do reinforce with wood, I would glue it and screw it.
Okay, after reading some other posts i think a 2x6 might be a little overkill but it definitely needs some re-enforcement. I would like to use thicker plywood but the edges can't be more than 1/2" or they won't slide into the aluminum rails that holds the bench up.

I think I will cut some strips of 3/4 plywood and laminate them to the bottom of the bench and then fiberglass over.

Thanks for the help boat bros!
 

RaftRat

Seaman Apprentice
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May 14, 2021
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36
Yea my brackets are only for 3/4 material, but they were really beat up so I had new ones made for my newer thicker benches
 
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