Sunday, October 16, 2016

Bronze Medallion







I'd decided to take a Bronze 11 week course. We had one class to come up with the concept and one class to finish the plasticine sculpt. Not a lot of time so I took it home over the first two weeks to try to get it the way I wanted it before the wax stage. Here's the progress so far.



Concept scribbles my initials and astrology signs


Capricorn J
Year of the dragon S


Starting plasticine rough
Starting plasticine rough
borrowed tools from a friend 
starting to take better shape
shape is getting there


adding texture but looking messy

 
added texture and fixed under cuts


after getting some advice cleaned up the texture
texture feels more like scales 

making the clay moulds 
Clay mould ready and poured plaster mixture



plaster mould came away clean for negative 




only a small amount of cleaning was needed 

wax poured in mould cooled and removed needs some work to clean it up
wax version now fused with the capricorn side needs more work to clean it up 

dragon side was bigger than the capricorn side 
some adjustments need to be made 
the two sides together are unbalanced 
not sure how to resolve this one

to be continued.... 


I'd decided to add a small base so that the piece could stand on it's edge on it's own.
Finally we are at the stage where we were able to add the wax funnel, sprews and vents.
 I didn't remember to take a picture before the next layer was added. oops. 





Here is the thing of beauty with three layers of compound with a thin layer of fiberglass on the medallion wax piece.



The next step was to make another cast mould case over the wax. The dry ingredients above needed to be mixed by hand thoroughly and I was the little helper volunteer to do this task. We ended up making 12 batches for each student. After the dry ingredients were mixed then warm water had to be mixed in.. thankfully I had my grubby clothes and an apron this was a very messy job. They used a drill mixer to finish the mixing  to get the compound really smooth. We used wet clay to form a base then stiff plastic (sort of like a crazy carpet) to wrap around our pieces. Added more clay to seal the bottom .. then the wet compound was added to fill. This week after the investment mix is set the instructor will remove the set pieces from the plastic and clay  and put them in the kiln at about 200 to melt out the wax. They will reuse the wax for another class. Then crank up the kiln to about 1000 to burn out the last of the wax to make sure they are totally clean for next weeks class. Next up is the bronze pour yay!


one Bronze ingot 






My instructor did the pour for us. She did three at a time and mine is the one in the corner closest to us.. they put the moulds into a container then filled the walls around them with sand. This helps hold everything in place. The bronze is melted at 1200 degrees. One of the moulds had a crack in it so there was metal leaking out of it that they had to contain. 


Tradition is to spit into the hot metal to put some of your essence into the piece. Even though mine had some small cracks it stayed intact. 


After the piece has had a chance to cool for about 20 minutes or so we threw the moulds onto the floor to smash it open. The mould and metal were still hot to touch. 



After much scrubbing with water and plastic brush to get off the inside mould composite the inner piece is finally revealed.  The "J" Capricorn side.
There are a few flaws in the design I suspect from having some bubbles in the first layer of composite I'd put on.



The S dragon side.

Next week we cut off the extra metal vents and funnel cup at the bottom and clean up the edges.


Sunday, September 18, 2016

Friday, January 28, 2011