stan: a torch and used motor oil are very useful for annealing and then rehardening small gun part such as springs, hammers and sears...before the invention of the gas torch, gunsmiths/blacksmiths used a coal fire.

neither the torch nor the coal fire are of much value in gun work without the skill to use them to achieve successful outcomes.

however, one can cook hot dogs with both; without much skill being required.

keep it simple and keep it safe...