Friday, April 9, 2010

Bronze casting!

The steps as I know them:

First you need something that you want to spent hundreds of dollars creating in bronze. I chose this person-in-bear sculpture that will be a part of a series to be completed over the summer.



The second step is to come up with a wax positive; A positive being an object to take a mold from. It’s called a positive because when you take a mold you’re capturing the negative space, like a film negative only 3D. That’s how it was explained to me.. anyways, that’s a positive, and you need one to get to step three.


You can either make something out of any material and take a mold from that and then cast it in wax, or you can make your first positive out of wax to begin with. I happen to love wax as a medium, it’s really strong but really easy to carve/model. It is very toxic when melted however, you can tell if you’ve been breathing the fumes. It’s gross. But it’s still great for sculpture making if ventilation isn’t a problem.

Once you have a wax positive you attach it to a long metal rod via sprueing. The long metal rod becomes the main pathway for your molten bronze once you’ve coated this whole thing with ceramic shell.

1. Metal rod coated with wax
2. Vent sprues
3. (2 sprues 1) Cup
4. More vent sprues (I meant to point that arrow at the non-vent sprues)
4. Non-vent sprues are at the bottom
5. Positive


The ceramic shell we used is a special kind of ceramic that has post-fired ceramic ground dust mixed into regular clay so it can withstand the temperature of the bronze. This part of the process is the first time that the entire thing can fall apart. The sprues need to be carefully placed and fixed in place or the weight of the positive with all the ceramic gunk on it will snap them and break your heart. Especially painful if you made the first positive in wax.

Once you have your ceramic mold back from wherever, the factory in my case, you’re close to being done. Just melt out the wax and fill it with bronze. For me there is very little control in this stage, I’m not strong enough to pour the bronze. There are a ton of things that can go wrong, including a hole busting open in the side of your mold, ruining the positive you spent months on and spilling expensive bronze all over the floor. Luckily that didn’t happen! Yeah!

Video of casting here

Removing the shell takes a while depending on how intricate your positive was. Took me 5-10 hours of chiselling and sandblasting which is not very much time at all actually, comparatively.

Clean-up and Patina! Removing the sprues uses a combination of zip-disk, cold-chisel, files, sand-blasting. The patina is a chemical you burn on that works like a paint and I believe also prevents oxidization, but I’m not sure on that part. I haven’t gotten to the patina yet.


And that's what I've been doing for the last three months!





Wednesday, March 31, 2010

Saturday, March 6, 2010

Ben: Can you please drain the bath tub?
Me: I want to put the water into that jug.
Ben: Why.
Me: Because I can water the plants with it.
Ben: *moment of visible, extreme cognitive difficulty* Do.. whatever you want.

Tuesday, March 2, 2010



Illustration for an editorial on the Olympics

I'm not into sports but that was a damn fine show, from what I had time to see. It's nice to be a little patriotic once and a while :D

Friday, February 26, 2010

Friday, February 5, 2010

Here's some concept stuff for work I'm doing.



People living inside bears! Doing a small bronze first and then big ones! Big sculptures, not big bronzes. Goodness no.

The top one, they're doing sign language, and then the other one they are both eating berries. You can beaaaaaaaaarly wait to see more! Huh? Huh? ;D

Tuesday, January 12, 2010

Wasn't he nice? Didn't he seem like a grandpa? I was missing him the other day so I drew him and read his Wikipedia page. Stephen Harper has lizard eyes and is not a good actor.