Low temperature alloys

[Marco Bernardini]

Since my shop will be off-limits until September (I've summer guests in my holiday house, which is just above it… not the case to make too much noise… they are not machinists :biggrin I have some spare time to make researches for a lot of things.
A friend of mine is a sculptress, and I looked how to make a bronze furnace for her works, since the foundries "for artists" are pretty expensive: for a piece like the one below, 40 cm high, the casting price is almost 2000 euro (but patina is included :biggrin.



Alas, homemade bronze is not exactly easy as lasagne to be done, and I was thinking to an alternative solution.
Aluminum would be easier than bronze, but this post by Hvontres (thanks, Harry!!!) pointed me toward low temperature alloys (Wood's metal. Field's Metal and similar) which could be a solution to make small metal sculptures with an affordable price.
Basically the "artsy" needs for this alloy are:
- must not be too expensive;
- the color must not remember recycled cutlery: even if without the patina of the bronze it must be at least dark or brown;
- must bear the "sun through a window" temperature, which can be over 50°C, without to melt like a candle;
- must be workable at a "kitchen" temperature, to avoid the need of a furnace;
- must not be toxic (even if I'd be happy to give to some of the most annoying clients of my friend a plutonium sculpture… in four pieces to be assembled :biggrin
I'm sure the collective knowledge of the forum has a good solution!

 

[Ray C]

Take your pick: http://www.engineeringtoolbox.com/melting-temperature-metals-d_860.html

Ray

 

[DMS]

You might take a look at Zamak. It is a zinc alloy with a pretty low melting point (watch the zinc fumes).

2000 euro is crazy... I guess it is somewhat specialized. 40 minutes north of me there is a place called "the Crucible" that is kind of like a commune for forging/glasswork/casting. You join for a yearly fee, and then can use their equipment. I'm guessing you have to supply your own materials though.

 

[Marco Bernardini]

You might take a look at Zamak. It is a zinc alloy with a pretty low melting point (watch the zinc fumes).

2000 euro is crazy... I guess it is somewhat specialized. 40 minutes north of me there is a place called "the Crucible" that is kind of like a commune for forging/glasswork/casting. You join for a yearly fee, and then can use their equipment. I'm guessing you have to supply your own materials though.

Here Zamak is the most common material for cheap door handles since the '60, so I think I can even found many of them and try to recycle them :biggrin:
The 2000 euro was the price for each of 5 fusions, including the mold, and my friend is on a tight budget, so I'm sure she got the less expensive foundry.
For "The Crucible" do you mean http://thecrucible.org in Oakland? It is a pretty famous place, between artists, and they have a long list of interesting workshops about everything, including blacksmithing and TIG welding.

 

[DMS]

That's the place. I am not a member, but I have always dreamed about taking classes. Since I have started accumulating equipment, the desire has become less and less...

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One experiment I recall from high school chemistry was to chemically plate a copper coin (US $0.01 piece or "penny") with zinc. The zinc formed a silvery layer over the penny. We then heated it in an open flame, and the zinc diffused into the surface, forming a thin, bright yellow layer of brass. I wonder if the same would work with a tin based alloy cast as the base, and then plate with copper and heat. Could be an interesting experiment, but tin based alloys may be more expensive.