Wing foam material properties?

[Trying to HLG]

Does anyone have material data for Dow Spyder foam or Dow High Load 60 or Foamular 600 (or for that matter any good hotwire cuttable wing foam)

There does not seem to be much available and Dow does not seem to supply it.

I have seen a post by Dr. Drela where he crudely compression tested 1" sq. blocks of both and found the Spyder foam to be _slightly_ stronger in compression.

Thinking back to my composites class in college ... isn't shear strength more important in a construction like a wing?

Thanks

[vintage1]

hah. That foam is produced as thermal insulator. No one cares about strength.

Compression is what is important. For inflight loads anyway. Basicially the real strength is in the skins, and the foam is there to keep them from buckling. That's compression pure and simple.

The easy way to get to what you want, is to make up a simple beam of foam with balsa (or glass) skins top and bottom, and load it up to see how much it can take before failure.

That would very quickly show both how the structure fails, and which foam was stronger.

My guess is that its pretty closely related to density. with particle size being a secondary factor.