How To Make A Backyard Foundry

All the information you need to know about a DIY metal backyard foundry. Learn how to build your own metal melting foundry for metal casting.

We recently moved out of our very first home together and relocated ourselves to the country. I wanted to take a little piece of the home with me and found the perfect keepsake in the way of some brass door handles. I decided to melt the brass down and cast them into mini axe handles and make a couple small key chain type things.

To be clear, I used Grant Thompson’s how-to videos as a basic guide for making the foundry and the propane torch. I modified a couple of things here and there and just wanted to share my thoughts and experience with you guys in case you are interested in recreating this project.

Here are the three videos to get you started followed by a little more personal input from my experience:

Plaster of Paris

Using plaster of paris is the quickest way to get going. The material is readily available at most hardware stores and it is very inexpensive. However, it is not very durable and will break down quickly. This route will certainly get hot enough to melt brass which exactly what I needed it to do. Since I decided to make multiple axes, I moved forward with getting some refractory cement which is a more robust option for extreme temperatures.

The plaster of paris route can be reinforced if you’re not able to get your hands on some refractory cement. Much like rebar in concrete, steel wool works very well to add some rigidity to the matrix. Using large stainless steel wool from something like a “Scotch-Brite” is the best route but the smaller stuff will work also.

Refractory Cement

 Refractory cement will certainly be more durable and will last much longer than plaster of paris. The only draw back is it is difficult to find on the shelf. Consequently, I ordered some on Amazon for about 20 bucks.

If you choose this route there is a slight change in the way the foundry comes together in the steel pale. Because this stuff gets so hard once it cures, you will need to drill your torch hole in the pale before pouring in the cement matrix. This is not the case with the plaster of paris; the torch hole can easily be drilled through the pale once the plaster of paris/sand matrix has cured using a good hole saw.

After drilling the hole through the pale, place a small pipe in the hole and leave it there while the refractory cement cures around it. Coating it with a couple dabs of oil will help with removing the pipe once the material cures.

Propane Torch

If you are following Grant’s parts list you will quickly realize there aren’t many of the needed fittings on the shelf at the big box stores….at least that was the case for me. Consequently, I just ordered everything through Amazon which made my life much easier. Other than that, there really isn’t anything else to offer in the way of advise for the propane torch.

I will caution you though that working with propane gas is extremely dangerous and you should be extremely careful. If you are not absolutely certain of the methods for heating material with a torch, I strongly encourage you hire someone to do it for you. Lastly, USE PROPER SAFETY ATTIRE. Molten metal is extremely dangerous; safety glasses, face shield, welding gloves, long sleeves, long pants, and leather boots are the absolute minimum safety attire for this type of casting operation. If you decide to take it on by yourself, take your time and know that you are operating at your own risk.

Be safe and have fun – April