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View Full Version : Wanting to get into metal melting/casting, where to start?



Com_VC
1st Nov 2011, 03:23 PM
Hi all,

I have been meaning to try out metal casting for awhile now and have been doing quite a bit of research.

What I want to do is mainly melt aluminium as I have quite a lot of aluminium castings, mostly that came from engines. I want to turn them into ingots so they take up less space.

Has anyone made a furnace before, if so how did you go about it?

Does anyone sell them in Australia for hobby use, I won't need anything big, just something for personal use.

Are there any classes available that can teach me about metal casting?

Thanks

Steamwhisperer
1st Nov 2011, 06:19 PM
Model Engineers Workshop magazine from the UK has all the information you need. It is issue no. 181. I don't think it is in the shops yet. I get it early as a subscriber.

Phil

Com_VC
1st Nov 2011, 06:25 PM
Cheers, i'll definatly grab that. Available at any newsagency I assume?

Bryan
1st Nov 2011, 07:17 PM
Meanwhile, here's a quick primer: http://www.woodworkforums.com/f65/how-can-you-melt-aluminum-without-furnace-141327/.
The answer to your question (where to start?) is: The 'Search This Forum' button.

RayG
1st Nov 2011, 07:48 PM
Hi Com_VC,

Joe (JHovel) is visiting today, and we are casting some pulley clusters out of aluminium, I'll take a few pictures of the process..

Regards
Ray

Com_VC
1st Nov 2011, 08:37 PM
Interesting Bryan, that's a good post. I'm tempted to dig a hole in the backyard just to try it out. hehe

Rayg: Look forward to seeing the photos.

4-6-4
1st Nov 2011, 11:13 PM
Dear Com, I have run mu own Non Ferocious foundry I can answer all you quires. I hang out at Newport Railway workshops most days send me a PM and I will give you a blow by blow if you can visit Newport. Yours 4-6-4

RayG
2nd Nov 2011, 01:05 AM
Hi Com_VC,

4-6-4 knows more about patterns and casting than just about anybody, I'd suggest you take up the offer, he will steer you in the right direction.

I can't really cover everything in one post, but I'll give you a quick overview...

So here is a quick run-down, first the furnace. For a home, non-ferrous foundry you can get by with a normally aspirated burner, and use light-weight zircon fibre blanket insulation, kaowool, isowool and cerachem are the brands that come to mind.. Don't waste time with heavy refractory linings, they might be more durable, but they take longer to heat and more power to maintain temperature..

This is my set-up, it's a water pressure tank, with the top cut out and lined with cerchem 1425, but kaowool is cheaper and would work just fine, I've got some refractory ceramic slips lining the inside where the flame hits the walls, but only because I'm playing around with ferrous (ferocious) casting. Bronze, and aluminium you don't need it, the zircon fibre is nasty stuff, and you need a coating to stop loose fibres, ITC-100 or a refractory lining (the brush-on type) is needed to seal the zircon fibre. The burner enters at a tangent so that the flame swirls around the crucible, I'm using A8, but I'd like to go a bit bigger for some parts... For aluminium you can use homemade steel crucibles. But the silicon carbide ones aren't that dear anyway. For cast iron, you need clay graphite crucibles.

This is a forced air burner, using a spa blower, running off a variac. But I used to use a reil style burner, and that works a treat for bronze.
http://www.backsaw.net/pics/Casting/DSCN0900.JPG
http://www.backsaw.net/pics/Casting/DSCN0901.JPG

The quick shut off valve is a must. as is the adjustable LPG regulator.

http://www.backsaw.net/pics/Casting/DSCN0909.JPG

Big bit of aluminium for an A8 crucible..

You can see the crucible lifting tongs on the side.

The next recommendation, is forget green sand, go buy some petrobond
http://www.backsaw.net/pics/Casting/DSCN0895.JPG

Here is the pulley cluster, the parting line will be across the middle, and the ends have been blocked off with some plywood.

If I was to do more of these, I'd make a proper split pattern, but casting direct from
the original part as the pattern is all that is needed for this job.
http://www.backsaw.net/pics/Casting/DSCN0896.JPG

http://www.backsaw.net/pics/Casting/DSCN0908.JPG

The part is set-up in the cope and drag and packed, I should have taken more pictures..

http://www.backsaw.net/pics/Casting/DSCN0914.JPG

Pouring, apologies for the fuzzy picture (I'll blame Joe, he had the camera while Josh and I were pouring..)
I'm pouring and Josh is on slag duty, stopping the slag from entering the pour.
You need good protective gear, foundry gloves, full faceshield, foundry jacket, or something that can handle a splash with molten metal.

If you are doing a lot of Aluminium, you might consider some C19 Nitral degassing tablets, I didn't use them on this pour, because the crucible was already
overfilled, and it would have bubbled over the top.

The red things are 56lb weights..

http://www.backsaw.net/pics/Casting/DSCN0918.JPG

The crucible was full to the brim for this casting, and we just made it... The riser just filled as the pour finished...

http://www.backsaw.net/pics/Casting/DSCN0922.JPG

Here's the finished part, with sprue and riser still attached, Joe will clean it up and post a picture of the finished pulley cluster..

Late night casting... always good fun.

Talk to 4-6-4 and he will add much more details than I can here, but I'd encourage you to have a go at it, and don't expect perfect results straight away.. just make sure you follow all the safety guidelines.

Regards
Ray

Master Splinter
2nd Nov 2011, 08:06 AM
This site is also a fun read....
melting metal in a home foundry, backyard metalcasting, metal casting (http://www.backyardmetalcasting.com/)

jhovel
4th Nov 2011, 10:19 PM
Here (http://www.woodworkforums.com/f65/restoring-servian-pedestal-drill-press-141363/#post1396951) are the photos of the pulley in progress and fitting to the drill press it was made for.
Thanks again Ray and Josh!
Joe

RayG
4th Nov 2011, 11:37 PM
Hi Joe,

I replied in the Servian thread, but no problem, it was a pleasure to be able to help.

Regards
Ray

Com_VC
6th Nov 2011, 08:35 PM
4-6-4: Thanks for the offer, I will definatly take you up on that I think. At the moment I only have weekends free due to work which probably won't suit you. When I get a day off during the week I will send you a PM.

RayG: Thanks for the overview.

Would the lpg be the best way to go? Is it safe? I noticed you have a big cylinder, if I were to go that way I would probably be limited to the sort you normally see on bbq's.

What thickness is your furnace? I was thinking of using a old compressor tank, but not sure if it would be thick enough, think they are only around 3mm.

RayG
6th Nov 2011, 10:13 PM
What thickness is your furnace? I was thinking of using a old compressor tank, but not sure if it would be thick enough, think they are only around 3mm.

I think it was less than 3mm, maybe 1-2mm, with ceramic fibre insulation, the steel shell really doesn't do anything other than provide a support for the insulation material.

Regards
Ray