Well, I tried a sugar coat on A2 steel to prevent decarburization. It may have done some good, but it very soon burned off, and one must raise A2 to orange-white heat and hold for a while, then allow to cool on a cold brick, to harden it.
I've ordered some Kasenite #1. We'll see if that helps.
Do a search on heat treating salts. There are a lot of different salts that are used in heat treating. Some are fairly toxic though. Depending on the salts used, you can go from a few hundred F to almost 2000F. Todd
Also, I bet I could put the metal and some table salt in a pouch made of heat-treating stainless steel foil, and the molten salt would act as a heat transfer agent, allowing the torch to heat the whole thing, not just the foil.
Another good idea, one than can be combined with the foil pouch idea.
sodium chloride melts at 1475F give or take a few degrees. So it's already in the right ballpark for most hardening uses. That, with its cheapness and relative safety, make it an easy thing to try out. (Note that safety refers to poisoning yourself, not pouring molten salt onto anything made out of wood, concrete or meat :-(
These are pictures of the test I did:-
I was experimenting with hardening some 4340 (actually BS 970 1955 EN24) by heating in the molten salt and then quenching directly into oil at 340F. The hardness at the surface tested to 54 HRC, which is about what I was aiming for. There was no scaling noticed, although the steel was blued from the oil.
The results were sufficiently good that I will probably build a couple of permanent salt baths, once I've got all of the current jobs out of the way.