Silver Casting: Preheating Molds for Optimal Pouring

Question
Hi Peter,
I've been reading many of your previous responses and they've been invaluable and quite helpful -- many thanks.

My question: I am melting pure silver in an electric furnace and pouring directly into a steel mold that, in particular, is deeper than it is wide.  As expected, I had problems pouring into the cold mold.  Usual strategy I guess is to allow the mold to come in contact with the furnace to allow it to warm as the silver is melting, however the furnace is well insulated except for the crucible opening.  Any alternative suggestions on how to preheat the molds?

So far have tried propane torches (considering trying an oxy-prop torch), craft oven, and a few other techniques, none to the level of desired safety, consistancy, and success.

Thanks,

M

Answer
Greetings,

Sorry for the delay, I've been contemplating your question.

I'm not convinced that your problem stems from the steel being cool.
However wraming it up will certainly help.
If you are doing multiple pours, perhaps you should sacrifice the first pour - and re-melt the metal if necessary - as this will make the mould warm enough for your requirement.
I'm thinking that the problem may be that the metal is cooling before getting into the mould?
You may wish to keep a torch on the molten metal in this process.
Also you need to blacken the mould and the easiest way to achieve this with an dirty acetylene flame........
The metal should be shiny in its molten state - borax added if it doenst look  shiney - and it should be poured in one fast and smooth motion.
Hope that helps.

Cheers, P