Aluminium Foundry

Step 10 My First Aluminum Sand Casting

After making a good foundry (still working with charcoals) and after making a strong crucible that is not failing after a couple of uses it is time for my first aluminum sand casting.
I started experimenting with sea sand casting which wasn't very successfull so I decided I wanted a good quality mold so I purchsed a 25KG bag of PETROBOND and I have to say it is super for aluminum casting.  It was a bit expensive but I will reuse it many times.
I made a simple Flask for the sand mold made from timber.
I was delighted with my first ever aluminum Star Trek Federation Insignia that I duplicated from a custom plastic resin kit I bought a few years ago.

For more info and links to Metal / Sand casting I made a new blog and everyone is welcome to have a look:
 http://flamingfurnace.blogspot.com/

Comments

[bherrboldt]

All I have to say it thank you so much. I just built my refractory/foundry almost exactly like yours. All I have left is to get ahold of some refractory cement and Im in business. This is awsome. You rock!

[imbignate]

Firstly, what sort of sensor are you using for a temperature gauge, and where is it mounted?

Second, what are you using as a mold for the ingots? They're all a nice standard size and very professional.

Third, this is awesome.

[NutandBolt]

The sensor I used is a simple and trusted multimeter that I got on Ebay. All that is needed is to set the multimeter setting to tempature and place the tempature wire in the furnace.
As for the ingots, I am using metal muffin tray (not teflon). All you have to do is pour the molten metal into it and you get a nice aluminum muffin. You can also make a container for the ingots DIY style like the one I welded from metal angles. I am using it to make slim ingots for my pipe cruicble.
Thank you.

[DIY-Guy]

Nice technique with filling the gas cylinder with water! An elegant solution to the problem of flammables. 

A professional iron worker once told me that cast iron cookware works well for a crucible. There are a variety of pans, pots, "dutch ovens" and other styles to choose from. Maybe there are cast iron muffin pans waiting to be found at a junk sale.

DIY-Guy

[NutandBolt]

Thank you, That is correct I heard the same thing regarding cast iron cookware used as crucible the only thing is finding the right size that will fit into my furnace ;-)

[paqrat]

I have been warned about using cast iron cookware if it has not been cleaned of all rust. If I understood correctly, what I was told is the combination of rust and molten aluminum can form something akin to thermite (possibly thermite itself?). If this is the case it could be very dangerous.

[absolutekold]

Ferrous oxide (rust) and aluminium do make thermite. Although the exact ratio's are industry secrets for each company they boil down a lot of rust powder and a lot of aluminium powder mainly for surface area considerations (occasionally it is doped with magnesium to help things along). At any level of rust build up on a pot that doesn't affect it structurally I don't think you have much to worry about. I've never had a problem. but if your worried put the offending rusty item in the smelter with it going full bore for a few minutes (be careful cause this smelter can easily melt cast iron if you are using charcoal ... I speak from experience of loosing an entire melt to this whoops(!?!)) by the time the pot has a barely visible glow in normal light there will be no more rust on it.

[TANZMEISTER]

Check out the book by David Gingry. Then you can make your own cast iron cricible

[bears0]

just so you know it's Gingery, not Gingry. :-)

[TANZMEISTER]

Details, details. And I suppose you want a crucible instead of a cricible?

[neffk]

Nice work.

It looks like you like welding and working with metal. Couldn't you make the sides of the foundry out of masonry or use a temporary form to cast the refractory cement? What you made is really nice, but it sets the bar pretty high for your fellow DIY folk.

[NutandBolt]

Thanks, My first ible "Mini charcoal furnace" is made the same way you describe, by using a form. This is my second furnace and I made it after lerrning from my trail and error  experimeting with my first foundy.
The problem with casting the refractory in a form is that eventually it will crack, so you need some metal container to hold the refractory in place. Another big advantage is that you can always change and repair the refractory and the gas cylinder will never break.
There are more options of making this furnace without welding for example using bolts, drilling holes and such.

[Ortzinator]

This makes me wish I had a concrete patio instead of wood.

[juanitosy]

Your step-by-step process showed use of charcoal as fuel, but the video showed use of gas fuel. Can you please explain how you attached the gas line and materials used. Thanks. SYGURONEVADA

[NutandBolt]

You have too look again on the video. NO gas fuel I never used gas fuel and I dont have gas burner at the moment. At the end of metal hose that is actually a hoover extension. The air blower that is conected to the end of the hose is simply my wifes electric hair dryer on full power. If you do decide to use gas You will have to make gas burner.

Instructable user EmmettO explains how to make it:
Propane burners are relatively easy. I make mine out of gas line parts. It takes some fiddling around with to get the lean/rich ratio right and the length of the burner (buy a couple gas nipples from 12" to 8" to try). The hardest part is drilling out the burner hole in a small 1/4 inch pipe. I think my hole is a #60 drill bit (maybe a #58) it's been too long. Start small and work your way up. You'll need an adjustable high pressure regulator too. regular 10 lb propane tanks are too small to feed a burner and will freeze after about a half hour. You'd need a bigger tank, or several tanks to switch between. All that said, a waste oil burner is the better burner it gets hotter and is cheaper to operate (at least in theory, its waste oil). The down side is that they tend to be more complicated and more finicky.

[juanitosy]

Thanks for the prompt clarification. I'll use charcoal then when I make my first similar foundry to produce aluminum cast parts to replace broken hard synthetic parts of hardware products like folding dollies and decors. You see I won a warehouseful in public auctions. I hope I can restore the defective products with more durable aluminum parts.

[TANZMEISTER]

Great ~ible! Ty!!!

[hairybaroque]

Beautifully clear photos and text! So sensible to keep it totally self contained with the charcoal; no feed joints to get a bit too hot and give up. Have you any plans to attempt producing dies to do repeat castings without sand? I like this ible!

[NutandBolt]

Thank you for your positive comment, at the moment I am at the stage of scratching my head what next will I make using my sand casting.
I think I might do some sort of aluminum sign....

[basefilm]

Great work. Clear, practical, useful. I appreciate the descriptions of what did not work (the first crucible) just as much as what did. It is maybe even more valuable from a safety standpoint to be aware of these things. Thank you!

[That Inventor Dude]

Dat is Awesoooome

[NutandBolt]

Thank you for your positive comment ;-)

[Whales]

Nice. I dont have plans to make this, but i read your original foundry 'ible and was interested on changes you made.

[NutandBolt]

Thank you for your positive comment ;-)

[robbtoberfest]

Very awesome!!!

[NutandBolt]

Thank you for your positive comment ;-)