Hello Ganoksin community!
I have a casting class coming up this fall, and I would like to be
as prepared as possible before hand. I have done plenty of casting
in the past and am very familiar with the mechanics of molds, sprues
and melting metal. I teach a basic fabrication class, but until this
season we have always had a different instructor teach casting.
Because of his failing health I have stepped into the role, so I
wish to clear out any remaining questions in MY head prior to
dealing with the questions the students will pose!
My question stems from the issue of melting bronze, and occasionally
larger amounts of silver. We will be doing a number of models and
casting techniques, and I want the students to be able to work in
bronze if they wish, to economize. Inevitably there is one person in
the class that wants to make a heavy project or wax tree, and this
leads to the problem I need to solve.
I have one Oxy-Propane Smith Little Torch with a rosebud tip, which
will be sufficient to melt 3 oz of silver. I also have two
Acetylene-Air torches that we use in the general soldering processes
in class. In the past we have used both A-A torches to melt larger
amounts of silver, but it takes a LOT of gas. In the past we have
had to refill tanks (B tanks) half way through the session when the
use was heavy. However, bronze (Herculoy) is a different animal, and
takes a lot of heat to reach pouring temperature (1975-2100F). I
imagine 3 ounces of that stuff would be very challenging to melt!
I just bought the O-P setup to alleviate some of this issue, but if
someone in class decides to make a heavy belt buckle or cuff
bracelet I want to know the limit of our melting power in advance so
I can provide proper guidance.
My question: If I need extra heat to melt larger amounts of metal,
can I use both Oxy-Propane AND Acetylene-air torches to heat the
crucible, or will the mixing of the flames create an unsafe
condition?
Thanks in advance for any helpful input!
Jean pSmith, Oxnard Gem & Mineral Society