Foams are not all the same. The Owens Corning "Foamular" (pink) polyethylene and Dow Chemical "Styrofoam" (blue) are extruded polyethylene foam boards that come in several grades. Owens Corning's Foamular 150 and 250, the grade found at most building suppliers, are 15 and 25 psi compressive strength, respectively. Foamular 400 (40 psi Compressive) is available but since it is not commonly used in residential construction I would need to buy it by the pallet. Blue Styrofoam is not as readily available in this area but it also comes in several formulas of similar strengths. The "Styrofoam FB" board sold by Aircraft spruce is 40 psi compressive strength. Now I don't know what or if there is a correlation between compressive strength to sheer strength but they are both important properties of core material. I've done enough research to know That I don't know enough about these materials. I'm going to give in and use what other people, more knowledgeable than I, have used. I use Polyethylene whenever the parts can easily be shaped with a hot wire. Another consideration is that the small cell size of foamular and Styrofaom FB do not develop as strong of mechanical bond between the FG skin and the core as Last a foam and the course grades of Styrofoam.
I just wanted to add few things to think about that seem to have been left out of the discussion. Pete Gauthier KR builder Woodburn, OR From: "Eric Kelsheimer" <erickelshei...@hughes.net<mailto:erickelshei...@hughes.net>> Subject: KR> 2lb. Foam To: "KRnet" <kr...@mylist.net<mailto:kr...@mylist.net>> Message-ID: <001f01c722d4$ef353040$6401a8c0@Ericvon<mailto:001f01c722d4$ef353040$6401a8c0@Ericvon>> Content-Type: text/plain; charset="iso-8859-1" I have a question for the list, what is the difference in the 2lb. foam you can buy from wicks or Aircraft Spruce and the stuff you can buy from the lumber company ? Thanks for your reply
