Low budget aluminum casting

[ericc]

Over the weekend, I tried some ideas for economical casting of aluminum. It was mostly successful. I looked around for some guidance, but a lot of internet resources warned against using spent propane cylinders in solid fuel fires. Best to try it myself and see what the problem is. I'll try to attach some pictures.

Hmmm. It says the photos are too large and Amazon photos cannot resize them. I'll try to figure something out.

 

[Latinrascalrg1]

Take a screen shot of the pic then post that, it should be a smaller file size.

Also not quite sure what you needed help with but i assume it was about using the propain cylinder as a crucible? If so the danger is cutting it open. In the past i have done so safety by removing the Schrader valve and filling with water before cutting. They work good for a few melts but will eventually burn through pending what temp you are running at.

 

[Hawkeye]

Email the photos to yourself. You should get a dialog box that lets you select the pixels. I always use 600 x 800 for forum pictures. When they come in, save them in the same folder, but change the file name. I just add an 'a' to the end of the original name.

 

[ericc]

According to a Google search, another app is needed. The dummies book says Amazon photos can do it, but if you follow the steps, it doesn't work. I'll try the resized pictures.

 

[ericc]

Hey, it worked! Anyway, the pictures show the firebrick furnace, the fuel (hedge trimmings), and the crucible (disposable propane cylinder with flared lid). The steel did not burn up. It didn't even scale excessively. The trick is to go slow and don't blow too hard. In addition, put a long piece in, but make sure that there are a lot of easy to melt pieces in the bottom. Small is good.

There were two problems that I had. First, the cans were not on a level surface, so I had to turn off the wedge shaped top on my lathe. Second, the molds were soup cans, and they appeared to have a coating which gassed off, leading to inclusions. Next time, it looks like a custom made mold would work better.

 

[RJSakowski]

Years ago, I used to do quite a bit of aluminum casting. I used a cast iron bean pot for my crucible. I made a propane furnace using firebrick and a homemade burner. I used a length of 1/2" black pipe for the gas supply with tees for three orifices. The orifices were made from brass pipe plugs drilled to the appropriate diameter. The fuel supply pipe was mounted inside a larger piece of pipe that fed air from a blower made from a variable speed automotive blower. The furnace could melt a 10 lb charge and could also melt copper and silver in it.

I cast my own lead fishing jigs and for that, I made a crucible from a four inch length of 4" black pipe. I welded a piece of 3/16" polate on the bottom and two washers for eyes for a handle. I use a small propane fired camp stove with a coffee can chimney for heat. I've used this setup for a quarter century now.

Back about forty years ago, I had some silver that I wanted to melt. I decided to use a small Corningware bowl for a crucible. It worked for melting the silver down but was fairly well toasted in the process. At the time, Corning had an unconditional guarantee against heat damage but somehow I didn't think that they would honor it for me.

 

[ericc]

...
Back about forty years ago, I had some silver that I wanted to melt. I decided to use a small Corningware bowl for a crucible. It worked for melting the silver down but was fairly well toasted in the process. At the time, Corning had an unconditional guarantee against heat damage but somehow I didn't think that they would honor it for me.

Ha Ha. Seriously, it is pretty interesting that it worked. I was surprised that the disposable propane cylinder worked. I expected it to explode at once or at least to spring a leak like the youtube videos. Not even close. It looks great, and it looks like there's no problem doing a second melt with it. Still, I think that I'll throw it away and get a new one for the next round, but perhaps do two pours with one furnace charging. One of the main reasons that I am doing this is that the garbage service doesn't like us recycling these things unless we cut them in half. As long as you are cutting them in half, may as well put them to some use.

 

[ericc]

I faced and turned one of the cast cylinders. It came out OK,except for the can grooves and the inclusions, possibly caused by the off gassing of the can inner coating. There must be a better way. When cutting apart these propane cylinders, there are leftover rings of steel that could possibly be repurposed into semi-permanent molds. Would it work to place one of these rings concentrically in a steel layer cake pan (no coating!) and fill the annulus with sand? Maybe, some retaining clips could be put in place to keep the ring from shifting. The aluminum would be kept in the inner circle by the sand around the bottom gap.

Do you think that this would work?

 

[Latinrascalrg1]

Look into "lost foam sand casting" to easily make aluminum castings of just about any shape. Or if you need to make a copy of an existing part look into "greensand" or "oil bonded casting sand" because they are both highly compactable to hold very intricate and detailed mold copies and it reusable with a bit of work to resofen.

 

[Latinrascalrg1]

Also forgot to mention coating the shaped foam part in a coating of plaster of paris slurry by dipping the piece and letting the layer dry a bit and then recoat until its got a nice shell. Then put that into a pile of regular sand into a hole in the ground and completely cover except the pour spout and vent stack but do not pack. This will give you a high detailed copy of the foam with a very nice surface finish compared to being very grainy effect you will usually get unless you use the finer mesh silica sand in the green sand form. Its the cheapest way to get the best surface right out of the mold if done right with every easy material access.