I used this in a couple kegs and a tiger ball. The stuff is suppose to be OK with the environment. HOWEVER, while the stuff doesn't expand, it DOES freeze. So it may eliminate the movement factor it extreme cold.
My blog is going to be a bit of an addition to my site Fightraining. My main how to make articles will remain there and be added to there. I'm hoping the blog will allow me to update things quicker. The blog will be mainly about interesting workout stuff I find on the web, brief descriptions of new homemade projects, my fight with diabetes, and occasionally other interesting things I find on the web.