My First attempt at Casting Aluminum

I have been wanting to cast some aluminum for some time. I used to cast my own bullets a few years ago with a LEE induction furnace, and it was a very satisfying undertaking. Lead has a very low melting point, and easy to work with. Aluminum has a higher melting point, but well within the backyard casters reach. I have been stockpiling Aluminum for some time, planning on building my own furnace, when a buddy of mine mentioned he had one for a very reasonable price. I carted it home, and its been a few weeks till I was able to spend a whole day getting to know it.
My dream furnace would be waste oil fired, and this one is coal powered. I figured; I gotta walk before I can run, and this one fit the bill. Its a well engineered furnace, and the workmanship on the tools is real nice. It came furnished with three 12 pound stainless crucibles, and three smaller crucibles, and all the associated tools to handle them.

It has a new Dayton squirrel cage fan thats whisper quiet to fan the flame.

 

From the top: that shelf raises the crucible about 6 inches off the floor of the furnace. I loaded that space up with charcoal before lighting it, and packed the outer space with some old oak flooring I had laying around.

Heres the ingot molds, and some of the tools.

The 1st burn, it took about a half hour to get up to temp.

This is about another half hour later. I was mixing cast, extruded, and sheet that was real dirty with paint. The top two inches of that melt is dross, and I still had 12 pounds in there.

The first set of ingots looked pretty good for a novice. I hadn’t used any flux or de-gassing agent, and the inside of the crucible showed it. The voids in the bottom of the ingots is due to pouring in a cold mold. Once the molds warmed up, this didn’t re-occur.

The second burn (of three total). I was learning a little with each load; like don’t even bother with aluminum radiators. All you will do is load your pot with dross, and little or no yield.. Very messy stuff, and not worth the bother. Here, you can see the top of the fan caddy needs a little re-engineering. The 2X4 on top was getting roasted. That’ll get changed after the shake down run.

Heres the total for the day, about 35 pounds ready to be cast. I learned one thing: Charcoal is NOT the way I want to go. It is labor intensive, and costly. But I did get my feet wet, and realize I have a few things to learn. Now that I know I can do it reasonably well, I plan to make some changes to the furnace. 1st is to try coal, and see how that works. 2nd is to build a propane burner, this seems to be the way alot of guys go. 3rd is to build my waste oil burner (all the parts are in stock). Any of these changes should cut my burn time, and cost, I would guess. I burned up two bags of charcoal today @ $6.00 per bag.
The upside is I moved enough scrap Aluminum out of my shop that I can almost see my lathe again! Once I get some more out of the way, and get the furnace to burn hotter, I might try and melt some of that copper and brass I’ve got in 5 gallon pails.
The ingots stack right nice, and I can just sit on it until the price gets right. For now, I’m holding onto the Aluminum for some casting projects I’ve got in mind. More to come…….

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7 replies
  1. Eric
    Eric says:

    Mick,
    Way cool. I can give you some 15 gallon drums for collecting waste oil and I can also give you my 5 gal buckets that i fill with oil changes.
    Has some other stuff in it besides motor oil. SOme bio-diesel, some methanol, tranny fluid and glop at the bottom. Read up on the nozzel and pump pressures for waste oil burners. Apparently there is some trick to it but well within your magical capabilities!
    🙂
    Regards,
    Eric

  2. skip
    skip says:

    this is very cool. a friend and I have been talking about this for some time, with brass as our first goal. Looks like AL might be a more reasonable first goal.

    I’ve got some waste oil for you as well…

    blue skies!

    –skip

  3. admin
    admin says:

    Skip,

    I was encouraged by my results after the first try, brass and copper will be in the near future, with cast iron the end goal. I was lucky and got a turn-key setup, but construction doesn’t look all that difficult. The refractory cement should be correct for the type of fuel you use. I’m going to be trying coal for a fuel next, and then on to propane and oil. Good luck with your tests, keep me posted.

    Mick

  4. Richard Kelly-Crapse
    Richard Kelly-Crapse says:

    A couple of things I noticed that might help.

    Make a refractory lid with a vent hole the size of large Dixie cup. It will raise the temp up higher and cut down on your fuel waste.

    When using charcoal, do NOT use the easy to light stuff. Use the hardwood instead. It works much better and lasts a lot longer. My furnace gets the charcoal gas to purple out the top of the lid. The inside is a lot hotter and I see white hot when I am doing mine. It is a small change, but worth it.

    Create a sand bed underneath your furnace in case of crucible leaks. This is a safety item.

    Other than that, good job!

  5. admin
    admin says:

    Richard,

    Since my last post, this furnace has been passed on to my friend Mark. He was looking to get started in casting, and I had acquired a Johnson gas furnace, so off it went. Not shown it the pics was a refractory lid, like you described. It worked pretty well, and the new furnace has one as well. I’m working out some kinks in the new furnace, but should be up and running soon. Thanks for the tips, and I’ll be throwing a sand bed in it.

    Regards,
    Mick

  6. jerry
    jerry says:

    Studied your Bridgeport move. Recently did one myself. no dissassembly though. I made three spoke handles for quill, v-speed, ram pinion. All ball knobs are aluminum. Looks and feels right.
    You and I are from a very similar mold. Im a laid off manufacturing engineer in california. Lots of home shop. Pretty much jack of many trades, however, metal shop and mechanics is funest. Really enjoyed your well done articles. cars, outboards, laminating, repairs of what is worth saving that comes my way. need to make a buck though. No customers on my boats for sale. ugg.

    jerry

  7. admin
    admin says:

    Jerry,

    Thanks very much. Most of the projects in the shop are a direct result of my cheapness, or I just can’t afford to repair the latest piece of clapped out machinery I’ve acquired. Casting and machining is the perfect combination for keeping old iron alive. I hope business picks up, and life provides you with plenty of stuff worth saving. keep plugging away.

    Regards,
    Mick

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