Blue foam, pink foam and balsa
In this thread folks have been asking about different foam densities. I thought the following summary may help in the discussion:
As Ollie pointed out "Blue foam" == Dow HiLoad, "Pink foam" == Corning Foamular. The following tables list products, strengths and densities of the commonly used (by modelers) foam products. Note the compressive strength for some products varies by axis.
From a CASA 3/99 newsletter we have the following "Blue Foam" data. (sorry for the poor formatting, I am attempting to attach the formatted newsletter as PDF)
Type Compressive Strength Compressive Modulus
Flexural Strength Density
FOAMULAR 150 15 psi min. N/A
60 psi min. 1.4 pounds/cubic foot (approx.)
FOAMULAR 250 25 psi min. N/A
75 psi min. 1.8 pounds/cubic foot (approx.)
FOAMULAR 400 40 psi min. 1400 psi min.
115 psi min. 2.04 pounds/cubic
FOAMULAR 600 60 psi min. 2200 psi min.
140 psi min. 2.4 pounds/cubic foot
Type Compression Strength Minimum Density
High Load 40 40 psi min. 1.8 pounds/cubic foot
High Load 60 60 psi min. 2.2 pounds/cubic foot
Grayboard 15 psi min. 1.35 pounds/cubic foot
From my limited experience with High Load 60, the above density for seems low, and I might better agree with the following data found in the same article:
Type Weight Compression Strength
High Load 60 2.8 pounds/cubic foot 60x60x60 psi
Spyder foam 2.3 pounds/cubic foot 45x15x15 psi
Interesting to note the better three dimensional properties of High Load vs. Spyder foam.
White expanded polystyrene is available in several densities and strengths. Type I is 1 pounds/cubic foot @ 10 psi. Type II is 1.5 pounds/cubic foot @ 15 psi. Type IX is 2.0 pounds/cubic foot @ 25 psi.
I hope lnjfarms doesn't mind that I point of the widely varying density of balsa and that he measured a piece that might be found in the typical local hobby shop. Contest grade balsa is about 6lbs per cubic foot.