I want to try and desolve a part of a stem that is broke off and is stuck in a watch crown.. What is the mixture of alum to water that I need to use…

Gary, I typed alum in the search tab and found quite a bit of information. Buster said to use 1 alum to 3 parts water. Hope this helps. Gary

Thanks for the input Gary....I will try Busters formula and see what happens...Thanks again...

I've had excellent results using alum. I suggest putting the crown in a shot glass with water and as much alum as will dissolve in the water. It works best (fastest) if you can apply heat to it. I use the hand-bluing heater that was described in this forum several years ago, but a hot plate would work well. It should be warm, but not boiling. When the alum is working, you'll see small bubbles coming up from the steel.