Ok! The experiment was a rousing success . . . Scientifically speaking, not necessarily in breaking new material ground.
Setup:
mixed up three batches of OoGoo, one with 2 struck spoonfuls of Cornstarch (CS), one with 2 struck spoonfuls of baking soda (BS), and one with one struck spoonful of each (CS+BS). Added an equal volume of "GE Silicone I" calk (windows and doors) using the TLAR heaping spoon method, and mixed.
Observations:
I keep forgetting how much this stuff stinks! I was outside under a porch fan, and the smell would tell me when I'd wandered out of the fan's airstream. Surprisingly, the smell eases off quickly (~5min) with the powder mixes.
Kinda hard to mix the stuff (not surprised), and goes from goop to paste to tacky to hard surprisingly quick. The baking soda integrates in a lot better, but seems like it stays tacky longer.
Final product:
Mixed each batch until integrated and the material held together, then gently rolled into a ball in the hand until set. set a side for at least 15 min.
The CS batch took on a light yellow cast, while the BS retained a cleaner white, although all were milky. Tried to attempt a water displacement test for density, but the test subjects weren't big enough to get accurate readings (water tension fowling the test). Interesting observation, though -- both the CS and the BS subjects sank (SG >1), while the CS+BS floated. Cut them open to get a look at the material texture and found a void in the mixed subject -- don't think it formed by reaction, but instead air caught while shaping (so much for the mix being lighter than either separate).
looking at the cut texture, the CS mix has a very solid rubber texture -- as if you'd cut into a glob of silicone. The BS and CS+BS subjects had a slight foam structure, giving it a slight spongy texture. It feels more flexible and slightly less dense, but not significantly less dense. There wasn't a appreciable difference in "density feel" between the mixed and unmixed BS batches.
For what it's worth, mixing in the soda doesn't appear to cut weight appreciably, but will soften the material quite a bit. Strength after 30 min from start is good, so could be used in an extended field repair (while you're watching everyone else fly). I'd recommend CS mix for things you need a hard flexible rubber part for, like a belly skid or landing peg, and BS mix for things you need a soft rubber part for, like a prop spinner or shock mount.
The CS is hard to integrate in, and gives little advantage in a CS+BS mix, so I'd stick to either/or, but not both.
