# Cast Aluminium Parts



## buster (Dec 26, 2013)

I am working on a prototype 'thing' and I need some cast aluminum shapes. I can make the pattern easy enough but I am a bit shaky on what would be a good economic melter and how large it should be. I assume size will be by weight of alloy to melt. My early efforts have been ok - I made a mold using Plaster of Paris (thoroughly baked dry) and had decent result with nice finish, but it was only a small bracket about 4" x 2" (cross slide thrust block for lathe) I used my O/A torch as melter.
I think my new parts will be from old auto pistons and I may be able make steel dies for the mold - depends on how simple I can design the parts.

Any advice on how to proceed is greatly appreciated.


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## davidh (Dec 26, 2013)

go here and join the forum. nice folks, LOTS of information written and a casting manual by Anon, the site owner is great.

http://www.alloyavenue.com/


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## Beone (Dec 26, 2013)

First thing to do is go over and register at Alloy Avenue. It's the home of most of the casters. Then get Gingery's book and bill Ammens book.  Most important is don't get too caught up in doing it perfect.  A workable furnace can be thrown together from an old can, sand, and clay dug from the backyard. It will work fine. It may not be the most efficient or longest lasting but the goal (at least for me) is the parts, not the most efficient furnace. Many, many ways to skin the cat.  Do something, learn a little then do more.  Lots of luck and Godspeed.  Lots of people willing to help at the site, as am I.

dave
beone


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## genec (Dec 26, 2013)

Mr. Pete has some great videos on you tube, on making the molds the mold boxes the sand and casting.


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## Hawkeye (Dec 27, 2013)

I made a foundry out of fire brick. Dimensions are up to you. That's an old BBQ cart.




Plenty of info on the net on making up your own burner. I found a couple of old fire extinguishers at the scrap yard that made good crucibles. The paint burns off, so stay up wind.



Gets pretty hot. A burner with forced air will get hotter, but I haven't needed to go there yet.


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## Ed T (Dec 29, 2013)

Google "MYFORDBOY" tons of great videos on pattern making, casting and machining the castings.


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## Glmphoto (Dec 29, 2013)

Hawkeye.......  Hey nice furnace!!!!  I really like the design. Of course I have to steel that idea now.   Thanks for posting .....pics speak a thousand words, dontthey?

Best Regards


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## GK1918 (Dec 29, 2013)

Mike, I just gotta ask, I have never been around this, ok I got the fire brick and the fire ex. part. Now the burner, do you use a regulator on
the propane tank or just go direct like a weed burner thing.?.  I have a share of good alum junk/swarf odds & ends I would simply like to
pour in like gold what ya call them block thingys billion bullion? something like a brick for stock.  I have a burner used for asphalt repares that
is direct of the propane tank, will that work?????????   Hawkeye
sam  I see your burner but whats the orfice like>?


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## Rbeckett (Dec 29, 2013)

Hawkeye,
How a bout a build thread on your furnace with a parts list and expose' on the burner assembly and plumbing.  I think many of our members would love to have a brief and thorough explanation of the entire build along with any caveats and cautions.  I for one would love to add  casting to my repertoire. A parts list for your burner outlining what parts and the modifications to the carburetor pipe would be a very nice part of the entire build to know, because that is where most builds fall short of reaching the required temps.  How bout it???

Bob


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## Hawkeye (Dec 29, 2013)

Sam & Bob,

I'm in the middle of a QCTP project for the new lathe, but I'll put it on the list for this winter. It's been a few years since I built the foundry. I'll have to take the burner apart to make up a sketch. IIRC, the oriface was drilled with a #60 bit. No regulator, just straight off the BBQ tank.

I think a tiger torch would work, but you'd need a bigger inlet pipe than I used. I have a feeling that my burner puts out more than the tiger. Don't forget a hole in the floor of the foundry, in case the crucible fails. You want the aluminum to run out rather than pooling in the cavity.


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## Glmphoto (Dec 30, 2013)

Hawkeye said:


> Sam & Bob,
> Don't forget a hole in the floor of the foundry, in case the crucible fails. You want the aluminum to run out rather than pooling in the cavity.



Hawkeye..... you are so right,,, Thank you.  May I add one safety comment. If there is a problem and your melt runs out the bottom hole of the furnace be sure there is something safe under it to catch that melt. I have a SS pan (like a restaurant style) filled with nice dry perlite. it can hold a full crucible full. You don't want that melt to run out on anything wet or concrete etc.  ZERO injuries ONLY fun!!!!!


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## Hawkeye (Dec 31, 2013)

Good point. Any moisture and all that heat would cause a steam explosion. The metal pan from the BBQ cart is below the hole. A cake pan would hold the contents of my larger crucible.


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## Dr. Duzlittler (Feb 9, 2014)

Hawkeye said:


> I made a foundry out of fire brick. Dimensions are up to you. That's an old BBQ cart.
> View attachment 66695
> View attachment 66696
> 
> ...



What's holding your bricks in the lid?


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## Hawkeye (Feb 9, 2014)

If you look closely at the edge of the lid in the second photo, you can just make out a groove at the edge of the angle iron frame. The angle iron is cut so that one side is only about 1/2" wide. Cut the groove around the bricks, then bolt the frame together with the narrow side in the groove.


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## David Kirtley (Feb 9, 2014)

I would be very leery of home mix refractories. Most are not going to be very durable or well insulating. If you are stranded on a desert island, go for it. When you can buy the real stuff cheaply, it is a waste of time. I bought some 1"x 20" fiber insulation on ebay for $9 a foot and a couple insulating firebrick for $8 each to make a small oven for heat treating and maybe a little forging.

It doesn't take that much heat to melt aluminum if you have good insulation. Insulated fire brick for a base is preferred. My personal favorite is not to use firebrick but fiber ceramic insulation (Kaowool is one name) for most of it besides the base. It is a lot lighter and easier to make something where you can lift the whole thing off away from the crucible instead of reaching down into it. Look at plans for Raku Kilns. Electric ceramic kilns put out more than enough heat to melt aluminum. Instead of building one, I would go that way. I just don't like messing with gas. For small quantities, the little glass fusing kilns are quite nice.

If you are looking for real power for melting other metals, you probably want to jump straight into oil burners. I wouldn't mess with building a burner for propane. They are too cheap. Look for the ones that they use for burning brush, melting tar, and melting ice. You can pick them up at Home Depot or such. Those are up in the range of 180,000 - 250,000 BTU if I remember correctly.  This is $20 at Harbor Freight.




The only bad thing about some of the casting stuff is paying shipping. Castable refractory is nice but expensive to get shipped. If you are lucky, you live somewhere with a furnace and boiler company nearby where you can buy without paying shipping.  If not, Budget Casting Supply isn't too bad (their prices include shipping).

If you have more money than time, Foundry101.com sells a nice little starter kit. It includes burner, crucibles, furnace, some tools and a small cope and drag with some sand. Not too bad at about $500 when you consider shipping. It gets bad when you are shipping sand and cement.


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