Saturday, October 15, 2005

Playing with Fire

I like to play with fire.

I had to do quite a few castings at work last week, so I took my camera up to the shop and had Sarah take a few pictures of me casting. Well, the flame is definitely more intense than what the camera shows...

In this project, I'm casting mass produced sterling silver pieces. I've charted the weights, and have weighed out the pure silver + copper I need to alloy the metal into sterling silver, and have wound up the centrifuge. I use an old "button" from the previous sterling casting and alloy the rest to the proper weight.

Torch is lit, getting ready to alloy silver Posted by Picasa

Alloying the silver in the crucible Posted by Picasa

Once the silver has been alloyed into sterling and the old metal has been melted into the alloy, I take the flask from the kiln and place it in the cradle. Now that's hot shit you don't want to touch with your bare hands.

Placing the flask in the cradle. Posted by Picasa

This particular casting called for 157 grams of sterling silver, quite a large amount of metal. I use a large flame with a high oxygen content for a higher temperature flame to melt the massive amount of metal.

Turning the oxygen up on the torch to get a hotter flame Posted by Picasa

I keep space between the crucible and the flask, until all of the metal is in a liquid state.

Melting all of the metal (alloyed metal + old metal) to a fluid liquid state Posted by Picasa

Then I push the crucible to the flask, keeping the heat on the metal, rock the crucible to break off any "skin" on the surface, then release the centrifuge.

Centrifuge is released, molten metal flows into the flask Posted by Picasa

Post casting -- you look for a button.

That's what the flask looks like once the casting has been done. The black thing in the middle is the silver "button" Posted by Picasa


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