[TheForge] Aluminum smelting

[xlch58 at swbell.net]

Aluminum casting is not that difficult.  There are dangers, but 
blacksmithing can be as dangerous.  There are a number of books on the 
subject geared to the amateur, Dave Gingery's come to mind as the most 
basic.   The one concern is his source of scrap.   Generally aluminum 
alloys vary in properties.   Good scrap for casting is material that was 
cast before.  Crutches and the like are generally made of extruded 
aluminum.   While you can cast material from melted extrusions such as 
aluminum doors, crutches and worst of all cans,  they will generally 
have a lot more dross and will not pour and flow as well.  This will 
make the quality of the castings suffer.  If you are just learning, this 
is a double whammy.   You may be trying to figure out what you are doing 
wrong ( poor venting, wrong pour temp, poor mold design, too small of a 
sprue, not enough risers etc) and the real problem may be your choice of 
scrap.  You are best off starting off with clean scrap made up from 
castings that are made from alloys that are know to pour well.   Lawn 
mower engines fit the bill well.  

Charles

fnanvil at aol.com wrote:
> The economy of it depends on what he wants to cast.  Besides a furnace, 
> crucible, and tools for handling the hot metal, you need flasks, 
> correct clay and your patterns.  And the knowledge of what you are 
> doing so you do not get moisture into the molds.  Scary to think of 
> what could happen with liquid 1400 degree aluminum and moisture.
>
> I would take the scrap and turn it in for $$ at a local scrapyard.  Or 
> find a small foundry that will take the metal in return for casting 
> done for you.
>
> Bottom line...don't do it yourself without a lot of knowledge and 
> equipment.
>
> J. Kavett
>
>
> -----Original Message-----
> From: Mark Novak <mark at fireworkspdx.com>
> To: The Forge <theforge at mailman.qth.net>
> Sent: Wed, Sep 9, 2009 11:47 am
> Subject: [TheForge] Aluminum smelting
>
>
>
> My friend has accumulated a large amount of supposedly high-quality
> aluminum scrap from hospital surplus (crutches, etc...). He was
> wondering how to melt it down and cast it. Any good sources of info/
> recommendations for him?
>
> Thanks,
> Mark
>