Monday, October 19, 2015

Casting a Bas Relief in Aqua Resin or Forton

I've been busy moving into a new studio space and casting some bas relief sculptures for the shows that I'm in. I've got a quick peak into the casting process here using my Polytek rubber mold and Aqua Resin. You could also use Forton for this type of casting:

I have been quite busy moving into my new studio space. My new relief sculptures have been juried into several shows and I have been casting them. Here is a quick peak at the process:
1) Set up materials. I'm using Aqua Resin but sometimes use Forton. I have a gram scale, disposable cups of several different sizes, gloves to protect my hands, stir sticks (popsicle sticks work well), a drill with paddle attachment for mixing. I set up on newspaper for easy clean up when done.
2) I have my Polyteck 74-10 mold set up in the plaster/forton mother mold and have brushed in the first two print coast of Aqua Resin. I do two print coats to capture all the detail letting each dry before adding the next. After the first two coats of Aqua Resin have hardened I begin the laminating process. I mix batches of Aqua Resin (or Forton) and brush on - then I apply about 10% by weight of fiberglass strand. For the sides and small detail areas I'll use 1/2" and 1" strand and for the larger areas I use 3"-4" fiberglass strand. I continue to brush in coats and add more fiberglass until the entire piece is thick and strong enough. I build up an area for attaching the hanging wires as the last coat.
3-4) I let the entire piece rest over night - Forton and Aqua Resin need a 24 hour cure time in the mold to ensure it is strong before demolding. I carefully peel the rubber mold from the casting. I used 2 coats of Polytek 7300 so the piece will release but there is a fairly strong suction bond that require slow and careful efforts so as not to put too much pressure on the rubber or delicate areas of the casting. You can see the strands of fiberglass extending from the casting as I pull off the rubber.
5) The finished casting is removed from the mold and washed with soap or degreasing agent to cleanse the surface of any of the mold release. Next I will use a rasp to remove the excess flashing and fiberglass from the edges. Then I will sand those edges smooth before priming the entire piece and starting the patina.
This bas relief measures 18"w x 24"h x 3"d and the final casting weighs about 10lbs. I find the process of casting to be laborious but the finished product is a nice stone-like casting with the benefit of capturing detail like plaster but having the strength of fiberglass and light-weight.

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