Rev. 2002-12-31, 2003-02-07, -04-17, 05-21, -06-01, -07-20,
-21, -08-29, -09-14, -11-16
2004-06-27, 2005-02-24, -08-01, 2006-02-02, -02-5, -03-21, 2007-11-13,
2008-01-29, 2009-02-20 (layout), 2010-01-31, -11-14, 2012-06-27
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|A glory hole provides more than enough heat to melt most metals including copper (1981F), but not iron (2802F) (A list of metal specs) But a glory hole is awkward for melting trash (i.e. scrap metal with paint and key rings.).|
melt aluminum from cans in a specially built melter (next) using a cast iron fry pan on a long metal handle. A
relatively short 1/2" angle iron piece (about 24") is
firmly bolted to the pan and fits inside the end of a longer
piece of conduit, held by a single bolt. I also have a
multipurpose foundry, glory hole, forge
which is nothing more than a cylinder lined with insulating
castable refractory with a burner port in the side. This unit
uses small pots of the same material as is used for glass. Which
metals can be melted in iron (lead and aluminum) and which
require a pot (brass, bronze) can be judged by what is used for
TIL ALUMINUM MELT - Even if the flame is aimed directly at the pan (as below), if the overall temp is a bit low, the handle of this iron pan will suck enough heat out to produce a chilled lump of aluminum under the slag. Raising the temp and stirring will melt the lump. 2006-02-02
|Using Insulating Castable Refractory
This is the form for building a cast furnace for melting aluminum cans following a couple of others that didn't work as well. Although this is not the finest photo in the world several points are visible:
|Keeping equipment outside, especially refractory insulation, requires protection from the rain. This shield gains strength from the curved conduit and corrugated sheet metal. The pivot at the curved back conduit puts the cover evenly over the equipment and permits raising the cover enough to let hot gases by. Metal lets the cover be closed if it starts to rain while stuff under it is still hot. 2003-11-16|
|This is the burner used with the aluminum melter and (without the flared head) with the Firehole [it has since been rearranged so the gas enters through the T where the elbow is in the picture, so the gas flow will preheat without the blower supplying air.]|
[For instructions on building the insides, making a cleaner version, and using this go to Firehole ]
This is the first version I built. By the time this picture was taken it is clear that the metal "popcorn pail" type container was not a good choice for leaving out in the weather - or it should have been painted with high temp paint. Since the picture was taken, I have taken off the rusted shell and wrapped it with thicker, painted metal, held in place with stainless steel hose clamps. I also keep the unit covered, as it absorbs water and that probably contributed to the rust.
The lid in place is the one used for foundry work and the hole
in the side is the entry for the burner. Unlike most of my
burners, this one does not have a flared end, but the castable
was shaped to provide that. The entry is low for foundry work,
below the edge of the crucible, which sits on a fire brick.
Lead Melting - I needed to melt some lead for molding an insert weight in the whirly jig. Although I have a ladle shape on one end of my glass gathering ball/scoop, I didn't want to put a lip on that and it has a very long (6') handle. So I went in to my welding box for the pipe ends [which are sold a steel/welding supply places to weld to the end of high pressure pipe to seal the end] I had bought before and used on the scoop. I found I had more sizes than I remembered, so I took two out (2" & 3") and cut a short length of 1/2" square tubing about 20" long. I cut the tubing at a slight angle and filed the end with a half-round file to further match the shape of the dome, laid it on a flat surface and torch welded it. I heated the lip with the torch and pounded a lip with a ball peen hammer. Then I melted the lead. In the pictures, the small puddle of remaining lead has set in the ladle.
Lead is a relatively low melting metal that can be used to make small castings and to provide weight for balancing. It can be melted in iron and if not overheated will not solder to the material (like brass will.) Lead is toxic and if allowed to accumulate in the body can cause brain damage and other problems. It should be handled with respect and when hot should be used in a well ventilated space. Shavings of lead should be cleaned up and hands washed after handling and before eating. Lead used to be used in paint and gasoline and both were removed (in part) to protect kids from lead in the environment.
|The photo at right shows
the pieces in making a new crucible for brass melting. A blank
was made up by stacking Styrofoam 2" block glued with yellow
wood glue. A disk of wood was also glued on and the wood was
screwed to an adaptor plate with a nut to fit on my flat grinder.
When the glue set, the cone was shaped with a rasp and cut free
with a saw. The form was covered with thin (dry cleaning type)
plastic. Old T-shirt material was dipped in plaster of Paris mix
and wrapped around the form like making a cast for a broken arm.
When the plaster was set, the form and plastic were worked out.
Unfortunately, I was not careful enough and the plastic left
wrinkles on the inside of the plaster. I relieved that by making
some more plaster and coating the inside. The crucible mix was pounded out 1/2"
thick on a flat counter, sealing the seams and making a sheet
equal to the circumference of the mold. A piece was laid in the
bottom and the sheet was rolled around my hand and put in place,
sealed with pressure to the bottom and at the overlap. When the
material had dried and shrunk, it was wiggled out of the (not
completely smooth) mold.
box was originally (over-) built to provide a strong step for a person to get
into my van as well as holding some tools. The lid is just 1/2" plywood resting
on 2x6's with routed in end handles and a rope loop shoulder strap.
When I started casting, it dawned on me that I could do rough casting of extra metal using play box sand, plus set the invested molds for pouring with support of the sand around them, plus have a fire proof place to set down the crucible of molten metal when transferring to the pouring handle. Also used for shaping clay for sagging as shown. 2003-07-20 This sand or some in a smaller container can be used to support an aluminum foil mold. I needed half an egg shape in plaster and had a full wooden egg. When I tried forming heavy duty aluminum foil around the egg then holding it in my hand, it distorted. When the egg plus foil was pushed into damp sand, then the egg removed, the foil was completely supported by the sand. 2005-08-01
|For the record, here are the sand casting cope and the tool I built for pounding
This red sand is very fine and has resin in it for bonding together to make it stick. I bought one bag years ago. In theory, it would allow me to make split molds using sand casting techniques. In fact, I have been unable to make it work, probably because I don't pound the sand firm enough so the molds I have attempted have collapsed during casting, I have succeeded in a couple of cases doing open faced pouring with the item in the flat lower half. One item was an aluminum "Property Line" sign. Another was the puffer cone shown below - note the rounded top of an open pour (more) A third was a color powder cup from a plaster model. I haven't tried very hard to make this work. 2010-02-01
|These are tools built for
handling the crucibles and molds. The upper unit, left end in the
insert, is used for pouring crucibles, which are lifted with the lower unit
and set inside the ring. The left ring was originally too large and
was cut and overlapped without re-welding it.
The lifting unit was originally too weak to easily lift a crucible full of brass, so the straight 1/2" square tubing was added for stiffening. The lower (left hand) curved pieces have been reshaped to fit the fairly thin space between the crucible and Firehole wall and bent in to get under the edge. The pieces are also not aligned, one is under the other when closed, to permit picking up smaller shapes, like investment tubes. Looks ugly, works okay.
|This is actually smaller than the stuff to the left, 5/16" rod, for picking up small muffin cup sized crucibles either from above (left) or the side (right) On opposite ends of the same rod. 2003-07-21|
|This iron pot was purchased just for the purpose shown: to melt aluminum in the glory hole for larger pours. An iron rod U first built for lifting slabs for reheating glass was rebent to fit along side the pot under the side flanges, to permit removal and pouring. At this time, it has been used for one sand casting which came out flawed but closer. 2005-02-24.|
|Alloy/Material||Melting Temp (F)||Ratio of Metal:Wax (Wt)||Flask Temp (F)|
|Fine (Pure) Silver s||1761||10.5:1||800|
|Yellow Gold 18K s||1700||16:1||900|
|Gold (Pure) s||1945|
|Brass b||1652 (melt) 2150 (pouring)|
|Beryllium Copper s||1800||8:1||800|
|Silicon Bronze s||1850||9:1||900|
|Casting temperature should be 100 to 150F above melting temp. (Src: s=Swest Catalog, back cover, b Budget Casting)|
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