I have never used a torch to melted metal for casting. I have always
used an Electro-Melt Furnace. I guess I am somewhat prejudice.
I strongly recommend using an Electro-Melt automatic melt furnace
for the following reasons:
You can control the temperature of the metal more accurately than
you can with a torch. The temperature reading on the controller may
not be the exact temperature of the metal but once the controller
temperature is set each melt will be a consistent temperature even
if it is not at the temperature shown on the gage. If you have a
problem with metal temperature you can correct the controller to
provide a metal that will cast properly.
The flask temperature at pour will be a consistent temperature
because the time from removing the flask from the oven until you
pour will be consistent.
It is much easier to have a consistent temperature of both the flask
and metal at pour when using an electric furnace.
You can fill the furnace to its maximum capacity of metal and make
several pours with in 5 minutes of each pour until you use all the
melt metal. The 5 minute delay between pours is mandatory to allow
the ring of the crucible to reheat between pours. If the crucible
ring is not reheated after a pour before the next pour the ring will
chill the metal as it is poured.
The controller will maintain the temperature of the metal as long
as it is powered. This allows you a little more freedom between
Pouring Metal from the Electro-Melt furnace is like pouring your
morning cup of coffee.
It takes about an hour or more to melt the first batch of metal to
pour temperature in the 30 oz 120 volt Electo-Melt Furnace. It takes
about 20 minutes to heat succeeding batches of metal.
The graphite cruicible is expensive and will have to be replaced
after about 20 to 30 reheats.
I do not recommend the 704-072 melt furnace as it is designed. It
is cheaper than the Electo-Melt furnace but I believe it is much more
dangerous. You will have to remove a very hot crucible with maybe 800
grams of molten metal from the furnace using long handle tongs.
Because the tongs are long it will be difficult to place the
crucible in the proper place to pour the metal and hold it there as
the metal is poured into a small flask. Controlling the crucible as
it is rotated to pour the metal will be difficult. The groove for the
tongs will disappear as the crucible is used making it useless. I
would guess that the grooved crucible will not last as long as the
If the 704-072 furnace had a handle like the Electo-Melt and a way to
hold the lid open with the same hand that is holding the handle it
would be a much better buy.
That's my two cents.