Should I Remove the Flotation Foam?

I should say, how about the foam: Is it in good condition or disintegrating already? Will your floor be removable or not? I did a complete yacht interior on foam, shaved and covered with a 2 component PU skin, and the wood siding glued on it. If you can divide the pressure points well, this is a way to go. And neat too. If you remove the foam, leveling the new foam will be your main problem, since you do not have a original mold.

The foam might be integral to the structure of a hull-foam-liner sandwich. If so, any old foam removed should be replaced with new. This will minimize the local deflection of loads on the liner, and will increase the stiffness of the overall sandwich.

I don't know if this matters for the construction of this boat model; it is just a general idea.

If it is a closed-cell foam, it will retain most of it flotation even if there are small leaks into the foam space. Air space, however, would in time become waterlogged.

Like others have said is the foam in good shape or not.

The foam gives support to the fiberglass hull.

It the boat was swamped or broken hitting something the foam is there to slow or prevent it from sinking.

Think about liability and insurance for a minute. What would you think if you were out boating and something happen and it sunk. Your insurance co. found out after paying you for your loss that you had removed the flotation foam.

Or worst say you sell the boat at some later date, you tell the new owner you had redone the inside. Say new owner goes out and something happens and without that foam in place makes the new owner peril worse. Who do you think it will fall back too?

Sorta like removing or defeating the air bags of a car and not telling the new owner about it.

If the foam is rotten I would look into poly urethane foam. They make both type open cell and closed cell. The closed is the way to go it not as likely to water log. They make it in a slow expand so as not to push or distort.

One way I would use it would be to install all your floors and side walls with access holes to pour the 2 part mix foam in to the voids. The foam will fill and bond to the fiberglass hull and the wood to form a stronger structure than laying foam blocks. It would help to fill/seal any voids between the hull and flooring making less likely for water to infiltrate the spaces and voids. And you may have a stronger safer boat in the process.

Even the little Al-boats have foam blocks under the seats.

Charles

Found this link on Stratos boats. Though you might find useful info.