Monday, May 3, 2010

Broom straw casting

About a year and a half ago, my little (taller) brother got me the book
Practical Casting
by Tim McCreight. In the book, there is a short but clear description of how to use sterling silver scrap for broom straw casting to make organic looking pieces. I put it on my mental to-do list of jewelry projects because it looked fun, the set up seemed relatively low-cost, and I could finally recycle some of the scrap pile accumulating at my work bench.

To start, I needed straw. I found an old broom in the garage and decided to cut it up to use (let's not tell Lowell about that). Once cut, I bundled the straw together with a rubber band, soaked it in water for a couple of hours, and stood it up in an aluminum can.

I also needed a crucible. There are ways, apparently, to make a crucible, but I wasn't too interested in trying that. A couple of months ago, my siblings got me a gift certificate to Rio Grande and I used part of that to get the crucible. I filled it with my scrap pieces (ok, I didn't really use this much silver at one time, but this was the batch I planned to get through in one session of casting):

Side note: As I went back through my scrap to fill the crucible with an appropriate amount to heat, I realized that there was still quite a bit of useable silver in that pile. Sometimes I forget that, and I need to get better about going through the stash and using those pieces for pendant bails and embellishments. So I picked out the bigger pieces before moving on.

I moved the rubber band to the bottom of the straw bundle and spread the straw out to allow for some bigger casting pieces.

I heated the scrap in the crucible with my air acetylene torch until it was molten, then poured it slowly over the straw. Once I felt like I was done with that session, I poured some water over the (slightly smoking) straw, then took off the rubber band. I spread the straw out on some newspaper and sifted through it to get my newly formed pieces:

These are straight out of the casting process, so I still need to sand and clean them to use them in jewelry, but I'm not totally sure what I want to do with them quite yet.

This one, I think, looks like a demon riding a motorcycle, hair-flames blowing back in the wind:

All he needs is a couple of sparkly, faceted stones in his eye sockets.

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