John, You will be disappointed by hoe the metal performs if you use
aluminum wire. Aluminum wire is almost pure aluminum. It does not like to
be cast. I would find some scrap Aluminum that has been cast before, like a
transmission case or some other car part. Pure al will not fill the mold
very well and the resulting part will be hard to machine. To make aluminum
wire more suitable fro casting you will need toad zinc and copper. I believe
the correct amount would be about 50 new pennies. They are copper clad
zinc. Toss them into your melt after the al has melted You will need to
degas the melt after melting the wire.
Dan in Auburn
] On Behalf
Sent: Saturday, March 31, 2007 6:21 PM
Subject: [hobbicast] Re: foam and wax and your thoughts
If you already have the molding sand, make a wood pattern it will be
easer in the long run, if your first casting were to fail. Added
benefit of a wood pattern is a better surface finish.
--- In hobbicast@yahoogrou <mailto:hobbicast%40yahoogroups.com> ps.com,
"John Greer" <john16314@...> wrote:
> New to this group and I might as well show how little I know right
> from the start. I'm in the process of restoring/customizing an old
> british motorbike. I going to cast a steering stop to fit on an
> existing factory lug. I't will be a single part roughly
> in shape, about five inches long w/ a recessed mount to fit in the
> frame casting. I will produce a melt in a my very large charcoal
> forge. Material will be aluminium wire, cut to chips. Pour from a
> cast iron vessel in to a sand mold. Here is where I could use some
> help. I had planned to use paraffin wax to make a model of the
> but now I'm very interested in lost foam. Is there a commonaly
> avalible(hardware store) polly foam I can use? Do I need a two
> mold or can I place my part in a bed of packed sand w/ vent and
> holes. Can I pour w/ the foam in place or does it have to
> be "evaporated" first? With the foam in place would be much easier
> for me. I've worked for years in hot metal but never molten metal.
> plan to learn casting as an art as time allows, but for now I am
> hoping for a useable part. My learning curve will be short and my
> budget will be even smaller. If a member in central arkansas would
> interested in a small job, I would love to watch and learn.
> I'll be on my own.
> Thx in advance
> John Greer
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