to foam or not to

[shipwreck]

i removed the floor in my 16ft 1969 Elgin fiberglass v-hull there was nothing under the floor in the way of foam, should i install foam into underneath the new floor?

the west system book i am have dose not cover it.

what do you guys think?

 

[whywhyzed]

Re: to foam or not to

My vote is for foam. Here's a link for calculating how much.
http://newboatbuilders.com/pages/flot3_print.html

 

[sdunt]

Re: to foam or not to

I did add foam to my boat during the rebuild, but I did NOT use pour in place foam. I just am not convinced the stuff will not soak up water.

Being involved with construction, I used something I am familiar with . Owens Corning, or Dow makes it as well, Foamular building insulation panels. We use these suckers BELOW ground in construction and I have not seem them soak up water. I bought the 2 inch thick sheets at the Home Improvement store and cut them to fit..

http://www.shareaproject.com/pages/imageDetail,p,148,i,2768,00.html

This stuff is also cheaper than pour in place foam, yes its more work, thus the term sweat equity.. The 2 inch 4 ft x 8ft sheets are 5 1/2 cu ft per sheet. Given that water weights 62 lbs per cubic foot, and we'll discount the 2 lbs, call that the weight of the foam, so 60 lbs / cu ft times 5 cu ft = 300 lbs of flotation per sheet.