Block or Pour Foam

I just purchased a 1980 Galaxy Runabout and am having to redo the floor and foam due to rot and water absorbtion. I've got everything I need for the floor, but was wondering if it would be better to use block foam or pour foam between the stringers and what the difference is between the two. Quick advice would be appreciated as I would like to have it ready to put on the lake by Labor Day. Thanks.

Re: Block or Pour Foam

duplicate what was there.......


most pour in foam from the factory is structural.......block is not

Re: Block or Pour Foam

Pour it in and you will get more for your space. More will be able to fit due to being able to go into small spaces that you would cut block forever to get into.

Re: Block or Pour Foam

If the materials are similar:

I use block foam in rectangular application or where air gaps are allowed.

Pour foam conforms to the space, can expand to eliminate air gaps/voids and once you get use to it, it is a lot easier to use. A little bit messier and batch size matters.

Re: Block or Pour Foam

Haven't gotten to that point, adding foam, in mine yet (84 Galaxy 17' BR) but the foam in mine was definately not for floatation. The bow under the seats is foamed SOLID (hope I never have to service the wiring or the bow eye ) and the gunwales are solid too to about 3 feet forward of the transom.

The foam under the floor was poured in six "blobs" for lack of a better term. They were definitely there for strength/stabilization of the hull. Parts of the original plywood were still stuck to them. They were placed either side of the engine, either side of the cross hull brace between the stringers at the back of the under floor storage and under the seats on a line about the same as the back of the windshield braces along the gunwales.

So at least for me pouring is the only way to get it back to normal not my first choice but what can you do?

Luck with yours...

Re: Block or Pour Foam

I like poured or sprayed foam. Just cover up all adjacent areas. Wear disposable gloves and unless your real neat, expect to get some on your clothing. Once it dries, is hard to remove from porous materials.

Re: Block or Pour Foam

Thanks to everyone's response. I have decided to use 4 lb density pour foam. I talked a distributor at my local boat shop today and he said only foam in the areas where the foam was before I pulled it out.

Looking at how the foam was put in before I removed it, it was basically down the middle between the stringers and then a little on the outer stringers. Didn't look like it was put in with much care and they had even used some spray foam to fill in where one of the stringers had competely rotted out.

Anyone have know if the distrubutor was telling me right in just foaming where it was to begin with or should I foam the entire bottom. If I foam where it was that is almost the entire bottom not including the area under the gas tank, battery and jump seats. Should I foam under these areas as well or leave them be?

Thanks,

Will

Re: Block or Pour Foam

It sounds like this was redone before you got to it. If that is the case then how would you know where the MANUFACTURER originally put the foam?? Some of the other guys here are a lot more familiar with boat structure than I am. They will let you know if you are getting bad advice. For me I would err on the side of more foam than less At least out board of the stringers to fill in below the deck. I would assume that the deck and hull were expected to be foamed in place and all "stuck" together with the foam. It will add a TREMENDOUS amount of stiffness and solidity to the structure. If it is not the way it was designed then I don't think an 18' boat can be really too stiff. It's not as if you have to worry about breaking in two over a 60' roller or something. Just my thoughts...

Re: Block or Pour Foam

Sorry I didn't get back to everyone on my final decision, but I used the pour foam and errred on the side of more won't hurt and filled the area between all the stringers up to floor level. Thanks for your advice.