boat floor foam?

[Bigbartguy]

I'm replacing part of my floor on my boat and some of the foam is shot/waterlogged. it was the spray-in type.

anyone ever 'refilled' some spray-infoam on a boat bottom? where did you buy it and can I use some from Menards?

thanks folks!

[Hookmaster]

I don't know if the spray-in kind is closed-cell which means it can't absorb water. Closed-cell foam is what you want to put under the floor.

[cheesehead]

go to boatbuildercentral.com they have some of the best foam around and have done extensive testing with it.

[Surface Tension]

They make a 2 part foam product for boats to pour and fill the cavity.

A word of warning is don't over fill, leave a hole for the expanding foam to run out.

[Fish killer]

Hey Bigbartguy,

What kind of plywood or flooring material are you using? I have to replace mine and want something I won't have to worry about.

[83walleye]

Just to ease my confusion, is the expanding foam insulation that comes in a can for home use and such what you'd call closed cell or not? Will this stuff soak up water and add extra weight to my boat?

[cheesehead]

The foam in a can doesn't belong in a boat. it's like a sponge and will soak up water. Any high quality exterior plywood will work for flooring. however it needs to be sealed on the bottom and sides prior to installing it. Epoxy is the best thing to seal and glue the flooring in place with. Polyester resin (regular fiberglass) has a tendancy to separate and delaminate from other items where epoxy won't if the surface is properly prepared.

[Pat K]

If it is an aluminum boat do not use treated plywood. ACQ will corode any metals except stainless steel or double dipped hot galvanized steel.

Because of the wet enviornment in a boat, the chemicals are more likely to leach out of the wood. Our Universal Forest Product rep compares it to mixing a couple ounces of battery acid with your bilge water.

ACQ has been the only treated lumber available at most yards for the last 3 years. Everyone has warning lables in the area where they sell treated lumber, but most people don't read them.

Pat K

[Bigbartguy]

I used BC grade plywood and coated one side/edges with fiberglass epoxy. I used only stainless screws to replace any lost. trying to rivet is another story. Waiting on carpet now!