Re-Posted this from the builder forum... not much action going on there.
I know much has been said about blue insulation foam being a poor choice for FRP core construction. I would venture to say this is in reference to the typical Dow Blue insulation foam sold at Home Depot or Lowes. However Dow makes three other types of Blue insulation foams that have much greater densities and are made using a different process. So my question is....has anyone used the Hi Load 40, 60, or 100 version of the Dow chemical blue Insulation foam? I again I am not referring to the typical 25 psi blue insulation foam sold at the home improvement stores, but the Hi Load versions rated at 40, 60 and 100 psi respectfully.
The Hi Load 60 and 100 are used in concrete roof top heliport pads so it has to have great strength. A white variation Hi Load 60....is also nick named "spider foam" and is used in surfboard and Sailboard construction. I have a couple of wave boards (windsurferers) that I made out of this suff and they have been thru hell and are still fine after hundreds of hours in the surf wave jumping and surfing. I venture to say that a sailboard landing flat from a 15-20' jump with a 165# rider (plus the weight of the rig)puts a lot of strain (compression on deck/tension on bottom) on the foam. This seems like it could be a candidate for a divincell/corecell replacement where cost is a factor...
The Hi Load foam has a "grain" so it needs to be positioned correctly to take advantage of it's compressive qualities.