The following is for those of you on the list who might
be considering buying an electric metal melting furnace in the
future.
I normally do not get involved in evaluating a product on the
jewelry supply market but I feel I must comment on a newer furnace on
the market.
The newer METAL MELTING FURNACE 3KG uses a graphite crucible that
has a molded recessed ring in the upper portion of the crucible. The
furnace comes with tongs that are designed to grab the crucible at
the groove and lift it out of the furnace to pour the metal into the
mold.
In comparison the Kerr 100 gram electro melt furnace has a larger
crucible that remains in the muffle when pouring the metal.
Things to be considered when looking at this new electric melt
furnace. The comments about the grooved crucible are noted by XA. The
comments about the Kerr unit is noted by XB:
1A. The crucible must be removed from the furnace by tongs.
1B. The crucible remains in the Kerr unit.
2A. The crucible will cool down rapidly when it is removed from the
muffle to pour the metal. It will have to be reheated when
reinstalled in the muffle. Considerable amount of reheating after the
pour will have to take place with the grooved unit as compared to the
Kerr furnace.
2B. The crucible in the Kerr unit does not cool down as rapidly when
pouring metal.
3A. The crucible will deteriorate more rapidly when it is exposed to
air while being out of the muffle.
3B. The crucible in the Kerr unit is not exposed to air and
therefore will not deteriorate as rapidly.
4A. The inside diameter of the grooved crucible unit is 1 7/8
inches.
4B. The inside diameter of the Kerr crucible is 2 1/5 inches. The
larger diameter of the Kerr unit makes it easier to load big sprues.
5A. Pouring the metal from a crucible held by tongs that are around
12 inches long is not precise. There is a great possibility the
crucible might be dropped or the metal not poured exactly where you
want it to pour.
5B. Pouring metal from the Kerr unit is as easy as pouring coffee
from a cup.
-
While pouring the upper ring of both crucibles will cool. The
upper ring must be reheated before pouring another load. The upper
ring of the grooved crucible is much bigger that the Kerr crucible
and therefore will require more heating between pours. -
The grooved ring of the crucible will deteriorate. Grabbing it
with the tongs becomes more risky. -
An advantage of the grooved crucible unit is that it is cheaper.
Being less expensive does not compensate for its disadvantages. If
one is to buy the groove crucible unit I strongly recommend adding a
heat shield and a handle so that the metal can be poured directly
from the unit similar to the Kerr unit.
In my humble opinion if one is to buy an electric melting furnace
they should stick with the KERR model.
I have no connection to KERR.
Lee Epperson