Hi, I am brand new to metal casting. I've only even being doing metal working of any kind for the last year or so.
I build the "two bucks" furnace and the "upwind" propane burner that are featured on backyardmetalcasting.com to create the set up in the link below.
"2 bucket" crucible furnace
The only differences between my set up and his is that my propane burner has no regulator to control psi, my crucible is made of the refractory material, (measures 4 in outside diameter and 3 in inside diameter) and that the hole I put in the bottom of the bucket is the same size as the top bucket. (approximately the diameter of a soda can)
On my first attempt to metal aluminum my burner was creating a loud roaring sound and I could only open the nozzle on the propane tank so far or it would blow itself out. One of the times it blew itself out something happened and it would only release a small amount of propane. I fixed this by completely drilling out the previous mechanism in the tubing. (It was one of those push pin pieces where it has to be pressed in to release the gas similar to a tire valve)
On my second attempt the burner was not roaring by any means. I was a calm steady flame. I could have the nozzle to the propane tank fully open with out much difference. After 40 minutes of this all I achieved was an orange refractory, crucible, and aluminum. No where near the pink to purple color shown in the images on backyard metal casting. At best the aluminum was malleable.
On my third attempt I decided to try melting aluminum with charcoal so I put what charcoal I could fit into my refractory along with my crucible. It wasn't a whole lot but I had flame coming out the top which I did not really achieve with the propane burner. After several minutes the crucible and refractory were not even orange. So I tried hooking up my propane burner while it had the charcoal burning and putting a fan underneath it to blow air into the charcoal. This still failed to achieve the desired melt. Or even make the aluminum malleable. Admittedly I did not have a direct air source such as a hair dryer or a leaf blower and I did not use the propane burner for very long before I gave up on it.
I am trying to cast a 2 gear racks and a gear wheel for a project of mine among other less complicated things. I made the molding sand by mixing silica sand with fire clay. I am having the issue of the sand getting stuck in the teeth of my gear and coming up in the teeth after I try to ram it. I'm also kinda worried that when I pour the aluminum it will knock down the sand and ruin the gear pieces.
Also I suppose it should be noted that my major sources of aluminum is crushed soda cans. I don't really have any good solid pieces to use.
Thank you for all of your help. I appreciate any ideas or advice you can give me. Just let me know if there is anything else you need to know.