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 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 have put thru hell and they 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.
Regards,
Bob

Hi Bob,

See my comment in the other lead about home-built beachcat. If your Hi-load 60 and 100 foam is of the extruded polystryreen version then it is by nature unfit for board or hull construction (closed cell). Twenty five years we already tryed this type of foam in surfboards and we jumped them after 10 times in two pieces!
Here in Europe we know the foam also from Dupont in a green version.

Personally I have a great deal experience with this foam in building a highspeed trailer from this foam which broke the speedrecord for trailers on the road. I had to beat the foam on forehand with a steelbrush in order to create holes for better connection with the laminate. That is to say, after first removing the very thin rollerskin of the foam due to its fabricationmethod.

I think that the foam you mean is or PolyUrethan foam (clark foam for surfboards) or PVC foam which is known for its high pressure load. Weight of these foams are always a threshold for using it other then in sandwhich cores.

regards ronald