Activities on these pages about foundry work are very dangerous. The chances of having a fire, causing injuries, or even dying are very good if you are not careful. I am not a professional foundryman, and will not attempt to disclose all hazards. If you choose to try this hobby, every precaution must be taken to be safe. Remember, a hobby is only fun until you're standing in the middle of the street with your family watching your house burn.
When building a foundry, it is necessary to make a few tools also. This page shows how I have made a couple of tools for my foundry.
Ceramic crucibles can be bought, but they can get expensive if you break them. I make my own crucibles at work from 10 gage (0.135" thick) black iron. I start out with a piece 6-1/2" by 16-1/2", which gives me a crucible that is 5-1/4" in diameter and 6-1/2" tall.
After shearing the metal I roll it. We have a power roll at work that has 4" diameter rolls. The 5-1/4" diameter is about as small as you can get with this roll. And 10 gage is too thick for a hand roll. To make the bottom I cut out a 5-1/8" diameter circular plate.
I then weld the seam on the body, and weld the bottom to the body. These welds have to be very sound, so I use a wire-feed welder, and then go over any spots that I don't like with the TIG machine. I have also made crucibles out of stainless steel, which I just TIG weld. (Click here for an explanation of the welding terms.)
To lift the size crucible that I use I needed two pieces of 1/4" x 3/4" bar stock. I drilled a hole at the pivot point and installed an iron rivet. Then I put the pieces in the vise with the pivot point above the jaws. Then I heated the metal with an acetylene torch until it was a dull red color, and bent the pieces with an adjustable wrench.
It may seem that the hotter you get the metal the easier it will bend, which is true, but if the temperature is too high the metal will rip instead of bending. In the picture above I'm heating the metal. You can see the red color in the bar stock at the jaws of the vise.
In this picture I'm actually making the bend. The bars are bent 90°, and they act like a pair of those doohickies that you use to take corn on the cob out of a pot. (Sorry about the use of kitchen jargon in a workshop page.)
Boy, I need to get the camera set up right. I decided not to bend the end of the tongs to fit the crucible, but to form jaws for them. So I bent the bars out a little less than 90° and then bent them again to straighten them out.
Here you can see how I set up the tongs to weld. I took a crucible and set it on the table. Then I put the jaws around the crucible, and closed the tongs on the jaws. The cabinet clamp is holding the tongs tight. I wanted the tongs to be at an angle, so I elevated the handles. A few welds and they were finished.