Plywood floor replacement...Questions

[jonny rotten]

I'm starting to replace my rotten floor.
How do I remove the plywood from the sidewalls?
Will the plywood just pop off when I start prying on it? It looks like its wrapped in epoxy up the wall sealing where the wall and floor meet
I'm worried if I Sawzall it I could cut into the hull.
It seems to be coming off the stringers easy (so far) and the stringers are solid in the worst part of the floor so that's a good sign
I though I'd ask first before I damage anything
Any and all help welcome.

 

[PC on the Bayou]

I cut mine close with a sawzall and/or oscillating multitool cutter and then ground the rest away down to the hull.

 

[todhunter]

Agree with PC. The oscillating multitool is a must-have - use a respirator to protect from the fiberglass dust.

 

[PC on the Bayou]

Agree with PC. The oscillating multitool is a must-have - use a respirator to protect from the fiberglass dust.

Agreed. The biggest issue I had with the multi-tool is that you have to get good blades. The fiberglass works on them quickly to dull.

 

[jonny rotten]

No idea what I'm doing so maybe someone can help a brother out.
Sorry about the long post with dumb questions
This is not a restoration project. It's a 31 year old $2500 boat that I'd be happy getting 5 more years out of.

My plan is to dry fit, seal the wood with the spar/linseed oil/ mineral spirts mix I read about here. No epoxy no fiberglass. Carpet and new seats. Simple easy drinking beer on the water in 2 weeks project. Stringers are solid and intact with no water damage

Questions:
1/2 inch or 3/4 AC sanded one side plywood?
1/2" would work better for me as I need to slide out the back seat assembly to work on the motor and the extra 1/4 inch lip will make a difference (not changing engine area plywood) but I could make 3/4 work
3/4 seems like it will hold the screws better on the back to back seats for obvious reasons
As a contractor I know plywood is 16" on center framing. The center over the gas tank is really wide. When they built the boat they just doubled up on the plywood (in pic) in that area but it has no additional support. They used epoxy and maybe fiberglass over the whole top of the deck which I'm sure strengthened things.
Will double 1/2" plywood in that area be strong enough with no epoxy or glass?
Could I add a couple 30" CCA 2x4's in that area between the stringers flush to the top for more support.?
I know your not supposed to screw through the stringers as that will be a point where water can get in but again old boat that's not going to be around forever

The foam is flush to the top of the stringers in areas, which is therefore touching the bottom of the plywood. It's waterlogged what seems like the top inch. Should I let it air dry and add the plywood or shave it down an inch for some breathing room and to keep it off the new sheathing? It's not totally soaked all the way and it floats just fine. I'm thinking shave it down

Should I seal the perimeter around the hull and seam were the 2 pieces of plywood meet to help keep the water from getting under the plywood? I saw something they were calling " peanut butter" That I think was an epoxy. Could I just smear that around the perimeter for a solid watertight seam and carpet over? Any product recommendations

How to adhere plywood to stringers?
Smear some "peanut butter" on the top of stringers and lay plywood on top with some weights on it?

I have 2 sheets 3/4 sanded one side ply from another project I could use to save some money but it was painted on one side and the edges with 2 coats exterior paint. I'm assuming the seal mix wont help at this point. Should I use it or just by new plywood.

 

[jbcurt00]

I suggest you do it properly or dont do it all.....

 

[Emerger]

No idea what I'm doing so maybe someone can help a brother out.
Sorry about the long post with dumb questions
This is not a restoration project. It's a 31 year old $2500 boat that I'd be happy getting 5 more years out of.

My plan is to dry fit, seal the wood with the spar/linseed oil/ mineral spirts mix I read about here. No epoxy no fiberglass. Carpet and new seats. Simple easy drinking beer on the water in 2 weeks project. Stringers are solid and intact with no water damage

Questions:
1/2 inch or 3/4 AC sanded one side plywood?
1/2" would work better for me as I need to slide out the back seat assembly to work on the motor and the extra 1/4 inch lip will make a difference (not changing engine area plywood) but I could make 3/4 work
3/4 seems like it will hold the screws better on the back to back seats for obvious reasons
As a contractor I know plywood is 16" on center framing. The center over the gas tank is really wide. When they built the boat they just doubled up on the plywood (in pic) in that area but it has no additional support. They used epoxy and maybe fiberglass over the whole top of the deck which I'm sure strengthened things.
Will double 1/2" plywood in that area be strong enough with no epoxy or glass?
Could I add a couple 30" CCA 2x4's in that area between the stringers flush to the top for more support.?
I know your not supposed to screw through the stringers as that will be a point where water can get in but again old boat that's not going to be around forever

The foam is flush to the top of the stringers in areas, which is therefore touching the bottom of the plywood. It's waterlogged what seems like the top inch. Should I let it air dry and add the plywood or shave it down an inch for some breathing room and to keep it off the new sheathing? It's not totally soaked all the way and it floats just fine. I'm thinking shave it down

Should I seal the perimeter around the hull and seam were the 2 pieces of plywood meet to help keep the water from getting under the plywood? I saw something they were calling " peanut butter" That I think was an epoxy. Could I just smear that around the perimeter for a solid watertight seam and carpet over? Any product recommendations

How to adhere plywood to stringers?
Smear some "peanut butter" on the top of stringers and lay plywood on top with some weights on it?

I have 2 sheets 3/4 sanded one side ply from another project I could use to save some money but it was painted on one side and the edges with 2 coats exterior paint. I'm assuming the seal mix wont help at this point. Should I use it or just by new plywood.View attachment 339793

All of the things you are talking about you can do. People have been making boats out of wood for thousands of years. And there are boats out there, mostly aluminum, that have plywood decks with no fiberglass over them. If you're not going to fiberglass the plywood you should use pressure treated and simply paint over it with enamel paint. Screw it down to the stringers. It would be best to use construction adhesive on it also. If you can cut it to fit well enough around the edges you can use silicone sealant to seal it up.

All of the advice everyone is giving you here is good, it just depends on what you're trying to accomplish.

 

[jonny rotten]

All of the things you are talking about you can do. People have been making boats out of wood for thousands of years. And there are boats out there, mostly aluminum, that have plywood decks with no fiberglass over them. If you're not going to fiberglass the plywood you should use pressure treated and simply paint over it with enamel paint. Screw it down to the stringers. It would be best to use construction adhesive on it also. If you can cut it to fit well enough around the edges you can use silicone sealant to seal it up.

All of the advice everyone is giving you here is good, it just depends on what you're trying to accomplish.

Pretty much every post I read says not to use pressure treated plywood and to use " a good quality plywood like AC grade" and then seal it.. I was originally going to use PT

 

[Scott Danforth]

Go to the stickies at the top of the forum. 4th one is the DIY on restoration

Read links 14, 15, 18, 2, 3, 4a, and 4b in that order and all your restoration questions will be answered

 

[tpenfield]

Don't cut corners, else you will be doing it again in a few years. Don't assume the stringers are OK until you have fully removed the floor and the foam that may be below it. Often it is best to remove the stringers.

Lots of restoration threads here on iBoats that you can browse through to get a better understanding of the process and plenty of folks here to help along the way.

Most people enter a project like this trying to minimize the scope as you are, but then realize the problems are more wide spread.

As far as cutting out the floor, many folks set the circular saw to the depth of the floor (1/2" ish) and cut as near to the edges as possible. Then use an oscillating tool to remove the rest. Good thinking as far as wanting to avoid cutting through the hull . . . it happens

 

[jonny rotten]

Made some progress. Got the floor out.
I was going to use peanut butter for the deck/hull and plywood joint but it looks like 5200 or Locktight pl marine would work and it seems like that what it's actually recommended for?
My main concern is water getting under the floor and waterlogging the foam trapping moisture.
5200 is a watertight flexible bond/sealant so it seems like it would work
Should I use it?

 

[tpenfield]

As far as joining the floor to the side of the hull where the two meet . . . you are going to need strength more than adhesion. Else the boat's structure will be weak(er).

It is best to fill any gaps in the joint with Peanut Butter, then go over the joint with a layer or 2 of 1708 bi-axial cloth. That way you will have both 'strength' and and 'water tight'.

 

[KJM]

I'd take the foam out altogether, its probably wet on the bottom. Replace it with sheets of foam that are made for foundations insulation below grade, cut to fit. That way water can flow around it if it gets in, cut a hole in your stringers, seal well and let the water flow back to the bilge. Paint the plywood for the floor underneath to help seal it.

 

[GSPLures]

I would reconsider not using glass on the deck. The deck is part of the structural integrity of a fiberglass boat. Not using it might last 5 years or 5 trips anyone's guess.

 

[jonny rotten]

Sealing plywood deck today with spar poly, mineral spirits and boiled linseed oil mix
I'm reading different posts on the mix. some say 1:1:1 other say 1:2:1 mix ( double the mineral spirits} Which one is it? 1:2:1 will save me some money as it will go further

Do I keep applying it wet till it stops soaking in or wet dry wet dry? I'm assuming all at once but can't find an answer
Roller brush or paint gun?
If I use a gun what should I use to clean it?

 

[jbcurt00]

In what boat?

Could have been asked in your prior plywood deck topic:

Plywood floor replacement...Questions

I'm starting to replace my rotten floor. How do I remove the plywood from the sidewalls? Will the plywood just pop off when I start prying on it? It looks like its wrapped in epoxy up the wall sealing where the wall and floor meet I'm worried if I Sawzall it I could cut into the hull. It seems...

forums.iboats.com

I suspect you are mixing aluminum boat deck and fiberglass boat deck rebuild methods.

 

[jonny rotten]

In what boat?

Could have been asked in your prior plywood deck topic:

Plywood floor replacement...Questions

I'm starting to replace my rotten floor. How do I remove the plywood from the sidewalls? Will the plywood just pop off when I start prying on it? It looks like its wrapped in epoxy up the wall sealing where the wall and floor meet I'm worried if I Sawzall it I could cut into the hull. It seems...

forums.iboats.com

I suspect you are mixing aluminum boat deck and fiberglass boat deck rebuild methods

Seemed like it's own topic someone else might be interested in but but move it if necessary.....just trying to seal the wood. Any help on the questions?

 

[jbcurt00]

What boat?

 

[jonny rotten]

What boat?

19 ft cuddy fiberglass boat. about 1 1/2 sheets 3/4 ply

 

[jonny rotten]

I got no answers so I rolled it on then finished with a brush. It never stopped soaking it in. I used 3/4 of a gallon mix on one side of one sheet and it still wasn't pooling up.
Now I'm wondering how long it will to cure being I used so much it must be totally soaked through the wood? Originally I thought I read 72 hour cure.
Any ideas how long to wait before putting it in the boat and sealing seams and carpet?