Just curious where the guys doing heat treat on their own stainless with sub zero treatment are getting their stuff. I haven't had much luck tracking down dry ice anywhere to use in a slurry. Way back when I worked at a grocery store in high school, we got blocks in every day in frozen shipments, but they say they don't get any shipped in anymore. Additionally, I would probably have to buy a dewar to purchase liquid nitrogen, but I'm not sure where one would purchase nitrogen. Do you need some type of permit or can anyone but the stuff? Thanks guys.