Ever wanted to know the steps to building and using your own foundry? It has been quite a few years and involved some jackassery, but as I recall it went something like this:
- Start working on a Lotus Esprit and realize you need a unique washer that is hard to come by (about $5 if available).
- Buy a metalworking lathe to make said spacer.
- Discover that the lathe is missing a part.
- Get frustrated that the part is just an aluminum block but costs $100 with shipping.
- Realize that the part wouldn’t be too hard to cast.
- Source aluminum flashing, ceramic wool, ceramic paper, sodium silicate, nichrome wire, a temperature controller, a crucible, and castable refractory mortar (totaling well over $100).
- Assemble sourced items to resemble a foundry.
- Obtain approximately 100 cans of Miller Lite.
- Drink approximately 100 cans of Miller Lite.
- Melt approximately 100 cans of Miller Lite.
- Sand cast the part for the lathe.
- Use the lathe to make the $5 washer for the Esprit.
Seems legit, right? I have a kiln now and will probably never use the foundry again, but I am glad I built it for two main reasons: it was a lot of fun and it was really dangerous!
I am including some pictures, but I am not going to include detailed instructions on actually making it. It is unsafe, and doing anything like this is a very bad idea. However, I will include some generalities and observations in case anyone wants to use any of this for a more rational project.
A good source of nichrome wire is from the heater elements of an electric dryer, and it seems to be good to about 2000 F. It is important to do your homework on the length. It must have enough resistance to limit the current or it will be annihilated as soon as it is powered up.- Sodium Silicate (or water glass) is really neat stuff. I used it as a stiffener and makeshift adhesive for the ceramic paper, but it can also be used for making things fire resistant.
Ceramic wool seems to be good to at least a couple thousand degrees Fahrenheit. It is also a good thermal insulator. I had no problem touching the outside when it was 1700 F inside. You can also see that the electrical tape around the flashing didn’t melt or deform after operation.
- I heard that ceramic wool became readily available due to technology development for the space industry. That might be a rumor, but I would rather perpetuate it than research it. Feel free to let me know if I am wrong, and you will be eligible for today’s Pettiness Award.
- The crucible is not shown, but I initially used a cast iron pot to hold molten aluminum. I do not know if anything leached from the cast iron into the aluminum, but it hasn’t effected the functionality of the part.
- the whole thing ended up fairly light weight. I remember it being about 20 lbs.
- If you are thinking about making something like this to avoid buying a part, don’t. Just buy the part.
Feel free to comment if there are any questions. I don’t think I will ever use this again, but I might use some of things I learned for another project. Anyone interested in a portable electric “wood fired” 1000 Fahrenheit pizza oven?