I've been working with a charcoal fired Gingery style aluminium foundry
for two years and am getting a little tired of the trouble of operating
it, the smell, reloading... so I've been thinking about building an
electric foundry.

Unlike the charcoal or propane foundries there isn't much information
available on the net. I'm mainly wondering what gauge of nichrome wire
I should use if I want to be able to reach and hold a decent
temperature.

Any tips concerning refractories would also be appreciated. I've used a
Silica sand /Fireclay/Portland Cement/Perlite combination which has
tended to flake with use. I've heard of a Perlite/Furnace Cement
mixture which seems somewhat simpler to prepare.


Thanks
Jon

http://tinyurl.com/2kq78

JonJonJon wrote:
I've been working with a charcoal fired Gingery style aluminium foundry
for two years and am getting a little tired of the trouble of operating
it, the smell, reloading... so I've been thinking about building an
electric foundry.

Unlike the charcoal or propane foundries there isn't much information
available on the net. I'm mainly wondering what gauge of nichrome wire
I should use if I want to be able to reach and hold a decent
temperature.

Any tips concerning refractories would also be appreciated. I've used a
Silica sand /Fireclay/Portland Cement/Perlite combination which has
tended to flake with use. I've heard of a Perlite/Furnace Cement
mixture which seems somewhat simpler to prepare.


Thanks
Jon

Tap in to your local pottery supplies place. They will have the
firebrick, refractory, and nichrome wires you need. Also available online.

JonJonJon wrote:
I've been working with a charcoal fired Gingery style aluminium foundry
for two years and am getting a little tired of the trouble of operating
it, the smell, reloading... so I've been thinking about building an
electric foundry.

Unlike the charcoal or propane foundries there isn't much information
available on the net. I'm mainly wondering what gauge of nichrome wire
I should use if I want to be able to reach and hold a decent
temperature.

Any tips concerning refractories would also be appreciated. I've used a
Silica sand /Fireclay/Portland Cement/Perlite combination which has
tended to flake with use. I've heard of a Perlite/Furnace Cement
mixture which seems somewhat simpler to prepare.


Thanks
Jon

Go to a ceramics/pottery hobby store, and ask about kiln elements.

Steve R.


"JonJonJon" wrote in message
ps.com...
I've been working with a charcoal fired Gingery style aluminium foundry
for two years and am getting a little tired of the trouble of operating
it, the smell, reloading... so I've been thinking about building an
electric foundry.

Unlike the charcoal or propane foundries there isn't much information
available on the net. I'm mainly wondering what gauge of nichrome wire
I should use if I want to be able to reach and hold a decent
temperature.

Any tips concerning refractories would also be appreciated. I've used a
Silica sand /Fireclay/Portland Cement/Perlite combination which has
tended to flake with use. I've heard of a Perlite/Furnace Cement
mixture which seems somewhat simpler to prepare.


Thanks
Jon

JonJonJon wrote:
I've been working with a charcoal fired Gingery style aluminium foundry
for two years and am getting a little tired of the trouble of operating
it, the smell, reloading... so I've been thinking about building an
electric foundry.

Unlike the charcoal or propane foundries there isn't much information
available on the net. I'm mainly wondering what gauge of nichrome wire
I should use if I want to be able to reach and hold a decent
temperature.

Any tips concerning refractories would also be appreciated. I've used a
Silica sand /Fireclay/Portland Cement/Perlite combination which has
tended to flake with use. I've heard of a Perlite/Furnace Cement
mixture which seems somewhat simpler to prepare.


Thanks
Jon

No comment on the nichrome gauge, other than the fact that I used a
dryer element, which I don't recommend, unless nothing else is
available. But as far as refractory, I strongly recommend you go to the
trouble of finding a bag or two of commercial refractory. It will work
much better than the homemade stuff, and you'll be much happier with it.
I used A.P. Green Cast-O-Lite 30. A.P. Green is now owned by Harbison
Walker, IIRC.

--
Gary Brady
Austin, TX
www.powdercoatoven.4t.com

I have nothing on refractory materials, but on heating elements I would
stongly suggest that you research the device called a "Globar".

These are resistive stick roughly 1/4 to 3/8" inch in diameter that
become heated to an incandescent temperature when current is passed
though them. These are what were used to heat all of our refractory
furnaces used for semiconductor melts at RCA Laboratories during the
late 1950s.

Sorry, but I don't recall who made "Globars", but I suspect that they
must be still marketed. We controlled their heat simply by simply
connecting them to a variable-voltage transformer like a Superior
Electric 'Powerstat' or a Genrad "Variac" rated at 15 or 20 amps.

As I recall, the nice thing about Globar heating elements was that it
was so very easy to assemble a small, high-temperature, refractory oven
that could melt gold, copper, iron and steel using only a small pile of
firebricks on top of a lab bench.

Harry C.

wrote:
I have nothing on refractory materials, but on heating elements I would
stongly suggest that you research the device called a "Globar".

These are resistive stick roughly 1/4 to 3/8" inch in diameter that
become heated to an incandescent temperature when current is passed
though them. These are what were used to heat all of our refractory
furnaces used for semiconductor melts at RCA Laboratories during the
late 1950s.

Sorry, but I don't recall who made "Globars", but I suspect that they
must be still marketed. We controlled their heat simply by simply
connecting them to a variable-voltage transformer like a Superior
Electric 'Powerstat' or a Genrad "Variac" rated at 15 or 20 amps.

As I recall, the nice thing about Globar heating elements was that it
was so very easy to assemble a small, high-temperature, refractory oven
that could melt gold, copper, iron and steel using only a small pile of
firebricks on top of a lab bench.

http://www.cesiwid.com

makes heating elements, which I'm pretty sure were under the Carborundum/ Amoco brand name. The site mentions Global so
it's possible it's the same company now.

I looked at these for a glass melting furnace. These are silicon carbide
heating elements. As I understand it the usual method of powering them
these days is with a phase angle control and preferably a power sensing
controller. The element resistance increases quite a bit as it ages and
so the phase angle duration is increased to compensate for this. I
spoke to Kanthal and was told that they would make them to my resistance
spec within a given range at least. In the end I opted for Kanthal wire
heating as the capital outlay for the SiC elements and control gear was
much higher than for wire elements and I was intending to use the
furnace occasionally not full time. The SiC element have benefit of
higher temp capability, longer life and can be replaced in situ in a hot
furnace if so designed.

Cydrome Leader wrote:

wrote:

I have nothing on refractory materials, but on heating elements I would
stongly suggest that you research the device called a "Globar".

These are resistive stick roughly 1/4 to 3/8" inch in diameter that
become heated to an incandescent temperature when current is passed
though them. These are what were used to heat all of our refractory
furnaces used for semiconductor melts at RCA Laboratories during the
late 1950s.

Sorry, but I don't recall who made "Globars", but I suspect that they
must be still marketed. We controlled their heat simply by simply
connecting them to a variable-voltage transformer like a Superior
Electric 'Powerstat' or a Genrad "Variac" rated at 15 or 20 amps.

As I recall, the nice thing about Globar heating elements was that it
was so very easy to assemble a small, high-temperature, refractory oven
that could melt gold, copper, iron and steel using only a small pile of
firebricks on top of a lab bench.


http://www.cesiwid.com

makes heating elements, which I'm pretty sure were under the Carborundum/ Amoco brand name. The site mentions Global so
it's possible it's the same company now.

You need another Ginger book. He wrote on on an electric
furnace.
see http://www.lindsaybks.com/dgjp/djgbk/found/index.html

look for
“Lil’ Bertha” Electric Furnace

Dave will show you how to use common, low-cost materials to build
a 220 volt electric furnace for melting aluminum. You get
detailed how-to on making the three-part body, installing the
element, and adapting other components to make a fast, convenient
and safe melting furnace. Capable of 2300 degrees for hours. 5
1/2 x 8 1/2 softcover 67 pages

No. 4163 ... $8.95
GmcD

On 4 Nov 2005 15:33:41 -0800, "JonJonJon"
wrote:

I've been working with a charcoal fired Gingery style aluminium foundry
for two years and am getting a little tired of the trouble of operating
it, the smell, reloading... so I've been thinking about building an
electric foundry.

Unlike the charcoal or propane foundries there isn't much information
available on the net. I'm mainly wondering what gauge of nichrome wire
I should use if I want to be able to reach and hold a decent
temperature.

Any tips concerning refractories would also be appreciated. I've used a
Silica sand /Fireclay/Portland Cement/Perlite combination which has
tended to flake with use. I've heard of a Perlite/Furnace Cement
mixture which seems somewhat simpler to prepare.


Thanks
Jon

I built an electric furnace for brass about 25 years ago. Kanthal A1 is what
I used. get wire from a ceramic supply house and spin your own coils. I used
a kiln design book and my old college physics book to figure out how much
and what gauge. Basically use the amount of wire for 20 amps at 110 volts.
Support the wire continuously or it will sag and burn out. I used fiberfrax
for insulation. Very efficient but will burn out faster than refractory.
Karl

"JonJonJon" wrote in message
ps.com...
I've been working with a charcoal fired Gingery style aluminium foundry
for two years and am getting a little tired of the trouble of operating
it, the smell, reloading... so I've been thinking about building an
electric foundry.

Unlike the charcoal or propane foundries there isn't much information
available on the net. I'm mainly wondering what gauge of nichrome wire
I should use if I want to be able to reach and hold a decent
temperature.

Any tips concerning refractories would also be appreciated. I've used a
Silica sand /Fireclay/Portland Cement/Perlite combination which has
tended to flake with use. I've heard of a Perlite/Furnace Cement
mixture which seems somewhat simpler to prepare.


Thanks
Jon

On Tue, 08 Nov 2005 13:23:12 GMT, "Karl Vorwerk"
wrote:

I built an electric furnace for brass about 25 years ago. Kanthal A1 is what
I used. get wire from a ceramic supply house and spin your own coils. I used
a kiln design book and my old college physics book to figure out how much
and what gauge. Basically use the amount of wire for 20 amps at 110 volts.
Support the wire continuously or it will sag and burn out. I used fiberfrax
for insulation. Very efficient but will burn out faster than refractory.
Karl

Nit to pick: If you don't want to chance the breaker tripping out
on the thermal overload in mid run, size the load to around 80% of the
breaker rating continuous, or install a larger circuit. A 20A circuit
shouldn't be loaded higher than 16A continuous.

-- Bruce --

--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.

Good point. I worked for an electrician in high school and he came over and
hooked the circuit into the panel with the right size breaker.
Karl
"Bruce L. Bergman" wrote in message
...
On Tue, 08 Nov 2005 13:23:12 GMT, "Karl Vorwerk"
wrote:

I built an electric furnace for brass about 25 years ago. Kanthal A1 is
what
I used. get wire from a ceramic supply house and spin your own coils. I
used
a kiln design book and my old college physics book to figure out how much
and what gauge. Basically use the amount of wire for 20 amps at 110
volts.
Support the wire continuously or it will sag and burn out. I used
fiberfrax
for insulation. Very efficient but will burn out faster than refractory.
Karl

Nit to pick: If you don't want to chance the breaker tripping out
on the thermal overload in mid run, size the load to around 80% of the
breaker rating continuous, or install a larger circuit. A 20A circuit
shouldn't be loaded higher than 16A continuous.

-- Bruce --

--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
Spamtrapped address: Remove the python and the invalid, and use a net.