Thanks again for the input Gents, I've been able to get the salts up to a high enough temp to black a few pins but not managed to get any larger parts past the 'iridium' looking stage, I'd assume that's down to the small heat source , hopefully I can improve things there.
A small kiln or melting pot is starting to sound more appealing, cost may be prohibitive for one large enough to do a long trigger guard though.
That's something I need to look into.
Having ordered the hot plate in a moment of madness
(10-last couple in stock) I will have a crack at fitting an improved thermostatic switch , I believe the temp sensor is fixed to the plate so should be an improvement from the start. I can get thermocouples and all kinds of temp control gear from a guy I know who's an instrument man in the chemical industry (he's helped me out with my caustic tanks already) so should be able to cobble something together and do some trials. If it's fails miserably , a kiln or similar is the next step.
Thank you for all your ideas and suggestions, it's extremely helpful and much appreciated. I will get busy when it all arrives write up the results.
