First ingot from home made forge

[lole]

FYI some pretty cheap ones on ebay if they're suitable.

Stuff like this, $29 for the largest. Search and it'll come up with latest listing.

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[Noisydad]

Automotive scrap is a way better source of Al than cans as they have to much surface area (for crud) for the volume of metal you get. Extrusions are only a little better. Been using a pistons, heads, manifolds etc. for a better yield.

[Lorgar]

Automotive scrap is a way better source of Al than cans as they have to much surface area (for crud) for the volume of metal you get. Extrusions are only a little better. Been using a pistons, heads, manifolds etc. for a better yield.

Yeah the cans were not worth using in my (novice) opinion.

Need to formulate a list of likely sources for materials and check a few scrap yards to see if any will sell direct.

[Lorgar]

While I think of it, any suggestions on which casting sand to get Noisy?

[rainwalker]

Very impressed you can get those temperatures out of a few nick-knacks from Bunnings.

[Lorgar]

So how hot can you get the sucker?

Looked up aluminium is 660c melting point, pretty high for a bucket

How high can you go?

Just judging by the colour of the crucible glow (after Googling to see what means what) the base of it is about 900c. That's quite concentrated in about the bottom 1/3 of the forge but it's obviously a lot cooler in the upper 2/3.

One thing I've found helped is there is a small raised semi-sphere of plaster/sand at the bottom of my forge about 3/4 cm high. I've sat a circle of steel wire mesh on there then fuel goes on top creating a little void underneath it. Lets the air circulate better and gives it some run up to hit the ash and blow it out the top.

Because of the raised handle on my existing crucible I couldn't close the lid properly during my first burn and was loosing heat. I've removed the handle now so I can close the lid properly but still need a thicker crucible as discussed.

With the tweak to the base with the mesh, the fixed lid setup and a new crucible, I should be able to get around 1,000 - 1,100 max I expect.

[greyghost]

Automotive scrap is a way better source of Al than cans as they have to much surface area (for crud) for the volume of metal you get.

Radiators would be aluminium too?

Always see them lying around.

[Noisydad]

You can cast Al directly into ordinary red brickies sand (and I have) but add 5% (by weight) Bentonite. It's a type of clay and comes in 25kg bags - get it farm supply stores. It's used as a stock feed additive but we can use it to improve the stickiness off the sand and 5% coal dust (from foundry supply places) which will improve the surface finish of the casting. Mull it all together in a cement mixer with 4-5 big old chunks of scrap steel (50mm bar for eg.) and just a little water for an hour or more. you also need the sand just damp enough for the mould to stay together when you draw the pattern out after rapping to loosen it.

[Chronos]

Not sure using cans in future though.

Maybe I just didn't have enough but on my initial burn to cure the forge I put 6 or 7 cans in. There was about 2 tablespoons of liquid aluminium and a fist full of debris. Paint, ink, whatever else is in a can.

More crap than aluminium making it hard to see what was happening.

FYI aluminium develops an oxide "skin"

on such thin items as cans there's a lot of surface area (oxide and other surface contamination) for the volume/mass of the item

the oxide surface layer on aluminium has a much higher melting temp than the core of the material (thats what makes it more difficult to weld than steel) so your thin material will have more waste than thicker sections

try and get the highest volume to surface area offcuts you can, stuff like aluminium flat bars and solid bar will be more efficient to smelt than cans and thin stuff

Chronos

[anthillinside]

Sounds like Noisydad's been there, done that, got the tee shirt
Automotive scraps a good source, pistons are good, heads if you can handle them.
Avoid extrusions, they normally are alloyed with Magnesium, Zinc or other stuff.

[hootshoot]

Radiators would be aluminium too?

An aluminium alloy at least. Depending on the mix may or may not be useful.

[roob]

It's a type of clay and comes in 25kg bags - get it farm supply stores. It's used as a stock feed additive

They feed them clay?

[Lorgar]

You can cast Al directly into ordinary red brickies sand (and I have) but add 5% (by weight) Bentonite.

Got the sand, will check out the Bentonite. Cheers.

[Lorgar]

try and get the highest volume to surface area offcuts you can, stuff like aluminium flat bars and solid bar will be more efficient to smelt than cans and thin stuff

Doing the rounds to a few recyclers today to try and find a supplier of bars. Not going to bother with cans again I don't think.

[Lorgar]

Fortune smiles.

Found a scrap metal joint 10 minutes from home that sells aluminium for $4 a kg

[Noisydad]

It's a type of clay and comes in 25kg bags - get it farm supply stores. It's used as a stock feed additive

They feed them clay?

You would be amazed and maybe even shocked at what you can get cows to eat when it's all blended in a feed mixer wagon!

[Noisydad]

Here's some pics of bits and pieces from my back yard foundry that may be helpful...

Some tools I use...sand rammer, vent spike, ingate cutters, pouring sprue former, mould repair trowel, seedling tray sand sieve, pattern rapping spanner, sock of graphite powder for shaking over patterns to stop sand from sticking.

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Two piece flask for making your mould in. The two halves are accurately located with pins at either end. You'll end up making lots of flasks.

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A match plate pattern of a crankshaft mounted oil slinger ring for a 1945 Ruston Hornsby 2XHR diesel engine I restored.

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Match plate patterns for a throttle handle and bracket for my big 1947 John Deere GM two cylinder tractor.

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8" x 2" and 10" x 2" wheel patterns.

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Some things I've cast - 4' and 6" model steam engine flywheels, reloading press frame and my new invention spouting brackets to repair sagging spouting without taking it all off the house.

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Ingot moulds made from 2" channel iron for pouring left over molten Al into.

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[Lorgar]

Two piece flask for making your mould in. The two halves are accurately located with pins at either end. You'll end up making lots of flasks.

If I can find where the hell I put my power drill I might get to making one

[Lorgar]

Here she is in action.

Glowing hot crucible, just dropped the ali bars in.

Burning forge

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[Noisydad]

Cool!

[squirrelhunter]

Never would have thought you'd get that much heat out of bucket of sand if I hadn't seen the pictures.