Wednesday, August 20, 2008

THE BRONZE AGE





In July I took the very first workshop in the new BronzClay made by Metal Adventures.  It was held in West Lafayette Indiana a few days before the International PMC Conference.  The class was sponsored by Rio Grande and was taught by one of the best teachers and artists around, Celie Fago.  I went to the workshop with my dear, crazy friend Gail.  It was an amazing experience to be one of the first people to work with a brand new material.  I think my favorite part was the variety of things that people made.  Isn't it amazing that you can give 12 people the same raw material and the same tools and all 12 will make completely different things?  People made wind chimes, bells, bowls, small sculptures and, oh yeah, some of us actually made jewelry!  I decided to use the time to make the sorts of things that I often make from silver.  I made toggles, lentil-shaped beads, charms, pendants, rings, among many other things.  I wanted to see how the material differed from PMC .  It's an incredible material.  It molds well, carves beautifully and is incredibly strong.  It is a bit more difficult, in my opinion, to make rings and other components that are spiraled around objects like straws.  Even this just takes a bit of practice.  Firing the bronze pieces is very interesting.  A covered steel pan filled with the pieces and coal-based or coconut-based carbon is placed in the kiln and fired for 9 hours.  The kiln is heated slowly (250 degrees)  to a temperature somewhere in the 1516-1550 degree range ( there is some debate about the holding temp.) and then held there for three and a half hours.  The slow ramp time forces oxygen out of the steel container, creating the necessary reduction atmosphere in the kiln.  Out-gassing from the coal-based carbon creates the most amazing colors to appear on the surface of the bronze.  The coconut carbon is certainly a more environmentally sound choice, but doesn't produce the same amazing colors, but they are lovely all the same.  The colors are only semi-permanent anyway. The only down-side to the BronzClay that I have seen so far, is the long firing time required.
I have done at least 10 firings of BronzClay at home since the workshop.  They have all turned out well except for one load.  Many of those pieces were very brittle, as if they had a bronze shell and had not fully sintered inside.  The pieces snapped like twigs when I applied pressure to them.  This happened to one of Gail's pieces at the workshop as well.  Celie thought it could have been that her piece was too close to the edge of the pan and in a cooler spot in the kiln.  I'm not sure what caused it, but I think that maybe I crowded too many pieces into the kiln.  I decided to refire the pieces, this time giving them a little more room to breathe.  They came out great.  I think there is just going to be more of a learning curve and experimentation required here.  I must say that the results are worth it.  I had a very good reception to the bronze at my last show.

2 comments:

Stella said...

Hey Cris...
I stumbled across your Blog when I was reading Gail's blog. I'm STELLA, alias.. Colleen, Gail's friend and PMC adict from Cleveland. Just wanted to say "Hi" and let you know how great it was to meet you at the Conference. Hey, you're doing some really awesome things with the BRONZclay..... let alone the Silver clay too! Keep up being sooooo creative!

Cris Leonard said...

Hi Colleen! How Are you? Hey girl, send me your email address. I think you gave it to me, but it is lost!