replacing plywood

[luvthelake]

hi, i'm rebuilding a pontoon boat and i'm at the stage of replacing the carpet. the plywood is kinda coming off with the carpet. i just priced new marine plywood and almost had a coronary. can i use pressure treated 3/4 inch plywood and what if anything do i have to do to it to make the carpet glue stick to the wood and the carpet.
thanks

 

[gcboat]

Re: replacing plywood

Marine grade lumber pricing = instant heart attack. Yup, some pretty pricey stuff for sure.
You could use PT lumber but it must be completely dry before most glues and any type of resins will stick to it. If you're just gonna' cover it with carpet find some B/C exterior ply. Without sealing it you're probably looking at a three to five year life span - tops !!! So, consider your options. Buy some good lumber, seal it and forget about it or do what comes cheap and replace it a lot. Remember that fresh water will rot wood faster than salt water will, but it is indeed a lot nicer to your motor!

 

[steelespike]

Re: replacing plywood

If i was doing a deck it would be pressure treated.My comepletely un sealed transom is still good after 25 years. Outside year round in the water 8 months a year first 20 years.Original transom lasted 5 years.
Just check compatibility with aluminum seal contact areas, if necessary
seal both sides to combat warping.Any plain wood sealed is only as good as the first leak. A pin hole could start rot the first day out.

 

[rlk]

Re: replacing plywood

This spring I replaced the deck on my pontoon. I used 2 sheets of half inch, with each sheet running perpendicular to the other. I thought this would give it more strength.

Tried to find a glue to use on the carpet. Contacted several manufacturers and all told me they do not recommend using their glue over pressure treated wood.

I ended up getting rolls of double sided carpet tape and putting that around the sides and down the middle. Stretched the carpet as tight as I could, then stapled it to the floor. The staples held it long enough for me to screw down half inch aluminum L brackets along the outside edges. I put stainless steel screws roughly every 6 inches. These L brackets went up against the side rails.

The first time I had it in the water, I noticed the sun would cause the carpet to wrinkle. As soon as the carpet is out of the sun, the wrinkles disappear. Maybe I should have installed the carpet in the sunlight????

Anyway, I think the carpet turned out o.k. We'll see how it holds up after it has gotten wet a few times.

rlk

 

[12vMan]

Re: replacing plywood

I know it's rough doing this stuff for the first time.

Plywood is already cross-laminated when it is made. That's what gives it it's strength and helps keep it from warping, so you really didn't need to cross-lay it unless the mounting was set up in such a way that it could be laid in a herringbone or brickwork type pattern. It's usually better to have the seams not line up.

Carpet would eventually wrinkle as it wore in unless you used a carpet stretcher. Thinner carpet will tend to react to the sun faster than thicker carpet too. Also, unfortunalely, unless you used SS staples, they are going to rust, brake off and be a pain in the foot to someone before long, unless you've removed them.

 

[rlk]

Re: replacing plywood

Also, unfortunalely, unless you used SS staples, they are going to rust, brake off and be a pain in the foot to someone before long, unless you've removed them.

I could not locate stainless staples to fit my staple gun, so the staples were only used along the edges, and are under the aluminum L trim.

I realize thinner carpet will react differently than thicker carpet. I went with some thinner carpet because it was readily available and fit my budget. Also, with the aluminum L trim, it will be easier to replace the carpet in the future, should it need to be replaced.

If I get 5 years or so out of this carpet, I feel I'll have a good return on my investment. Time will tell....

rlk

 

[xxturbowesxx]

Re: replacing plywood

if its not to much trouble i would like to see pictures of this install..

 

[jeeperman]

Re: replacing plywood

Depending on how long you plan on keeping the boat, I would seriously look into using extruded vinyl or aluminum deck boards instead of wood and carpet.

 

[j_martin]

Re: replacing plywood

With a quick scan, I picked up on some points that need to be made.

1. Marine plywood is supposed to have no voids in the internal layers, where commercial BC plywood is allowed to. That's about the only difference. It needs to be used where predictable extreme strength is needed, such as in performance or high powered boat structures, like the transom.

2. Pressure treated plywood is completely wet when you get it. After all, it is treated with pesticide so it can get wet without rotting, why dry it out? That's why it's so darned heavy when you pick it up, and it curls up like bacon when it dries.

3. 2 layers of 1/2 inch plywood is not as strong as 1 layer of one inch. It is probably not as strong as 1 layer of 3/4 inch. That's just the way it works out when you figure the load is mostly carried by the "skin"

If I were going to replace that plywood, I would use the same thickness as the manufacturer did. I would use commercial outdoor BC, or even BD plywood (outdoor glue doesn't let go when wet, indoor usually does) . I would cut it to shape and then treat all surfaces with a couple of coats of Rot Doctor's CPES, paying special attention to the edges. Brush it on till it won't take any more. Put it in and it will probably outlive you, at a reasonable cost and effort.

hope it helps
John

 

[Bamby]

Re: replacing plywood

Check out pontoonstuff.com they did have deck plywood for $65 sheet. I think they have warrenty on it too. Plus deck kits avl. also. Hope this helps.
Gregg

 

[pugbro]

Re: replacing plywood

i am rebuilding a pontoon also and lucked out at a lumber supplier called PLYMART...It may not be a national chain but it is most good sized cities in Ga. they are going out of business and I purchased 3/4 in marine plywood for $60.00 a sheet.