In ‘A Matter of Honor’, one of the pivotal moments in the text was when Merrie and Amon decided to ignore the status quo and build their own steel foundry, or Tatara Furnace. It wasn’t as if Merrie invented the idea, simply that she recognized the value it brought and then successfully replicated the process. Well, in that spirit, the boys and I decided to build our own aluminum foundry. Unlike Merrie and Amon, we have no need to craft weapons to defend our sleepy little berg, but we do find the idea of melting aluminum cans to be pretty inspired. If you want to see the source of our inspiration – check out Grant Thompson’s much more refined approach.
I’m just going to assume you’re ignoring Grant and are hoping we set something on fire and got pictures. Check and check.
The idea we’re going after here is simple. Blow air across ordinary charcoal in a small space. It get’s really hot – enough to melt aluminum, not enough to melt steel. Put a small steel bucket (called a crucible) in the middle of previously mentioned, really hot charcoal and then drop aluminum pop cans into the crucible. Simple enough? Turns out it really is.
So here’s what we did:
Step 1 – Make Foundry
The first step is to build the actual foundry. We need a well insulated kiln that won’t radiate all of our precious heat outward. Turns out plaster of Paris is a great insulator so we mixed a batch, poured it into a galvanized steel bucket and then displaced a space in the middle with a plastic bucket (to be removed later).
Jacob pouring plaster into bucket with Matthew standing to mix. The plaster we were using sets in six minutes so we have to have everything ready to go.
Mixed plaster into the furnace’s bucket. We’ll push a smaller, blue plastic bucket into the top to displace a cavity where we’ll actually do the burning.
With plaster mixed, we filled the small blue plastic bucket with sand to help hold it down in the wet plaster. Once the plaster is dry, we’ll pour the sand out and peel the bucket out.
And not everyone needs to be hands on. It turns out there’s room for your’s truly to simply hang out and provide sage advice.
Step 2 – Assemble the Furnace
With a five quart cavity in the plaster furnace, we drilled a hole in the side, through the bucket and plaster. This is where we’ll inject atmo across the lit charcoal and make it really hot.
Looks like junk, right? It’s not. That’s everything, short of charcoal required to run the furnace. I didn’t show manufacturing the top, but it’s made of plaster, poured in the bottom of a five-gallon bucket and allowed to dry. The hair dryer and pvc tube are for pushing air across the charcoal, and the muffin cups are for forming our ingots.
As any video blogger can tell you, taking video and actually doing the work is pretty difficult, so we’re skipping a bunch of steps because we just don’t have that many hands not to mention, we’re completely new to this way of communicating. For now, I’m going to upload my videos directly to youtube and then link them to the blog. That may turn out to be a bad idea. I guess we’ll see.
Starting the furnace is pretty straight forward. I like to smoke meat and the quickest way I’ve found to start charcoal is to use paraffin cubes. Drop them next to the charcoal, apply flame and we’re off. Hopefully a video follows that shows this:
To heat the coals we need Mom’s hairdryer. Let’s hope she doesn’t find out:
With everything hooked up, we’re making real progress with adding heat:
And finally just letting things heat up
Good thing I have a place to hang out.
After things got heated up – we finally started adding cans. We had somewhere between 10 and 15 and would like to have had 40. Ultimately we really just wanted to see if we could melt aluminum.
It all camedown to this moment. We see if our hard work ends up in aluminum pouring from the crucible.
In the end —
What’d we learn? Well, nothing is as easy as it looks online and more importantly, if you want to melt soda cans, it’s not all that hard to do. Overall this was a fun project and it’s hardly the end, we have so many things we are excited to try now. But that’s another story entirely.