Flooring ?

[DIRTY DOG]

I have a 1989 Star Craft Islander and was wondering if it is nessasary to use marine grade ply wood for redecking ,or if plain treated would be fine.

The reason I ask is that Ive had different ones tell me that you can use plain treated and some one tell me that only marine grade should be used.

If marine grade should be use please explain.the resoning.

[Paulywood]

Terry it is my understanding that it is best to use a high grade plywood free of voids. But it doesn't have to be marine grade. You want to avoid treated as the chemicals interact with the aluminum. It is better to seal the plywood with an epoxy or oil based paint.

[strik]

You get what you pay for.. Like said above do not ues preassure treated wood.. If you seal the wood it will be fine but if water ever found it`s way in the seams you will wish you had spent the money on the marine ply it cost more for a good reason.

Like any good wood project it`s all in the planing

Best of luck

Strik

[Nailer]

Terry, get a sheet of MDO (medium density overlay) plywood. It has a solid core and is exterior grade. The current pressure treated plywood has Copper Quaternary in it, and will cause galvanic action (like acid) against the Aluminum.

Most of your home town lumberyards should have MDO (some may call it "sign board")

Ryan should have enough epoxy resin, and cloth left to coat you patch.

[Priority1]

Terry, All good advice above.

[Line Dancin]

My brother is redoing an old boat and was asking the same question. The marine grade wood is treated with different chemicals that wont allow natural warping and completely seals the wood including any places that you are going to cut. Even using a non treated and sealing, even though it wont rot as easily will eventually warp. Even if the wood is screwed so that you wouldnt think that it could warp it will and it can then chip the epoxy coat and allow rot. there was a guy at wood source in grand rapids that was explaining all this to us. You can call and ask for the guy that builds wood kayaks there and he can explain eveything to you. He highly suggested only marine grade in a boat. Espically if it is for flooring. Just going by what we were told. I know some others mught be able to suggest better than me. I am by no way a wood worker.

[DALEDOZER]

Here is a youtube link. This guy has rebuilt a couple boats and has very well documented videos of his repairs. In this video he shows the materials he uses.

[IRon]

There's always bit of a debate on plywood flooring. Definitely don't use treated for reasons mentioned.

Any plywood used in a high moisture environment if not sealed properly is going to absorb water, swell, de-laminate, rot and fail in a few years. No debate there.

So, to me anyway, why spend the money on marine grade plywood just to put it in unprotected and cover it up with carpet. Looks just like what you get from the factory, no doubt, because it is. And it'll fail, just like from the factory. If thats what you want, nothing wrong with that. Just have to re-do it every few years.

In my opinion, you can buy a lesser grade of exterior grade of 7 ply exterior grade wood or MDO as suggested (not cdx) for about half the cost. Buy some epoxy or fiberglass resin with the money you save and take a little extra time to seal it properly (edges, openings and screw holes). It'll last probably the rest of your life. JMHO. Good luck

[silver one]

Terry it is my understanding that it is best to use a high grade plywood free of voids. But it doesn't have to be marine grade. You want to avoid treated as the chemicals interact with the aluminum. It is better to seal the plywood with an epoxy or oil based paint.

Treated lumber is no longer treated with arcinic and new treating schedule they use to treat lumber do not make the wood corrsive against aluminum like it use to be. just an fyi to everyone.

[FsnMachine]

I had to fix my gas tank last year including cutting out a section of floor. I used exterior grade plywood but it all got coated and covered with Fiberglass resin. Hopefully I have no access for moisture. Then I covered it with a one peice rubber commercial flooring ( like they use in buses etc). I wrapped it up the walls and seal all edge. The water that gets on top should have no place but into the bilge.

[adrenalin]

Treated lumber is no longer treated with arcinic and new treating schedule they use to treat lumber do not make the wood corrsive against aluminum like it use to be. just an fyi to everyone.

You beat me to it.

[adrenalin]

There's always bit of a debate on plywood flooring. Definitely don't use treated for reasons mentioned.

Any plywood used in a high moisture environment if not sealed properly is going to absorb water, swell, de-laminate, rot and fail in a few years. No debate there.

So, to me anyway, why spend the money on marine grade plywood just to put it in unprotected and cover it up with carpet. Looks just like what you get from the factory, no doubt, because it is. And it'll fail, just like from the factory. If thats what you want, nothing wrong with that. Just have to re-do it every few years.

In my opinion, you can buy a lesser grade of exterior grade of 7 ply exterior grade wood or MDO as suggested (not cdx) for about half the cost. Buy some epoxy or fiberglass resin with the money you save and take a little extra time to seal it properly (edges, openings and screw holes). It'll last probably the rest of your life. JMHO. Good luck

Sounds like a good idea.

[DIRTY DOG]

There's always bit of a debate on plywood flooring. Definitely don't use treated for reasons mentioned.

Any plywood used in a high moisture environment if not sealed properly is going to absorb water, swell, de-laminate, rot and fail in a few years. No debate there.

So, to me anyway, why spend the money on marine grade plywood just to put it in unprotected and cover it up with carpet. Looks just like what you get from the factory, no doubt, because it is. And it'll fail, just like from the factory. If thats what you want, nothing wrong with that. Just have to re-do it every few years.

In my opinion, you can buy a lesser grade of exterior grade of 7 ply exterior grade wood or MDO as suggested (not cdx) for about half the cost. Buy some epoxy or fiberglass resin with the money you save and take a little extra time to seal it properly (edges, openings and screw holes). It'll last probably the rest of your life. JMHO. Good luck

After speaking with one of the persons that replyed this is the exact plan.

Thanks guys, I very much dislike haveing to do a job twice becouse it failed the first time.

[cycleridertoo]

Check the Iboat Starcradt forums. Today’s pt will corrode the aluminum.

[DavidWP]

Arsinic wasn't a problem w/ aluminum, the new treatment uses copper which will cause a bad galvanic reaction w/ aluminum. Check out www.tinboats.net, there's a ton of good info on there.

[A-Fishy-Anado]

Nailers and the last 2 post are correct. The new treating process embeds a high concentration of alkaline copper quaternary into the material and will have a galvanic (dissimilar metal) corrosion effect with aluminum. Some of the reactions (2 & 3) in the attached chart need outside conditional factors to thrive with the main factor being moisture. #1 which you will see is a condition of aluminum & copper contact in which corrosion will occur with no other factors considered other than direct contact.