Repairs and restorations
Mar. 2nd, 2019 01:57 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
offcntrI was recently asked by a member of the Art Center board whether I could help with a restoration. A wonderfully wonky mixed-media sculpture from 1982 had turned up in deep storage, somewhat the worse for wear. It needed a little wood restoration, which is outside my skill set, but also had about five ceramic bits--two hemispheres and three flanges--that were broken or missing, and another hemisphere that had come off, but looked like it just needed to be re-glued.
The original work sculptors had been woodworkers, I think, so they'd turned all the parts in wood, then made molds to cast the ceramics. Fred asked if I knew any wood-turners at Market who could make the molds, and I pointed out that it would probably be just as easy to fabricate the pieces on the wheel. Which is how I spent most of Monday morning (before the power failed) while firing my kiln in a snow storm.
The hemispheres were simplest. Open the clay down to the wheel-head, pull up and in, collar and narrow the top until it closes, not unlike how I throw cat banks and salt/pepper shakers. The tricky parts is getting the dimensions right, but I sacrificed a plastic binder cover to make templates, and used a pair of calipers to check dimensions. I had less shrinkage to deal with, because I'm using white earthenware (necessary to get the proper glaze colors), and since there's no shrinkage between dry and glaze fired, I can actually adjust measurements by sanding if necessary.
The flanges were a little trickier. Center the clay, open again down to the wheel head, spread the clay out. At the correct width, split the clay, with some coming up to form a short cylinder, the rest moving out to make a flat skirt. Again, check measurements with calipers for diameter, ruler for height, and template to set the curved transition. Made three to cut six, and used a fourth, unsuccessful attempt to calculate shrinkage (Marking a six-inch span that I'll then measure at leather hard.)
I created a template on the computer to show me where to cut down the thrown pieces, sized using the shrinkage from above. I centered each piece, using the bulls-eye circles on the template, and using a combination of eye-balling and ruler, and a very sharp fettling knife, I cut six half-square flanges out of the three originals. Now it's time to dry, while I chip out broken bits and compare glaze samples. I'll be using commercial glazes from Georgies, I think, rather than trying to mix my own.
The original work sculptors had been woodworkers, I think, so they'd turned all the parts in wood, then made molds to cast the ceramics. Fred asked if I knew any wood-turners at Market who could make the molds, and I pointed out that it would probably be just as easy to fabricate the pieces on the wheel. Which is how I spent most of Monday morning (before the power failed) while firing my kiln in a snow storm.
The hemispheres were simplest. Open the clay down to the wheel-head, pull up and in, collar and narrow the top until it closes, not unlike how I throw cat banks and salt/pepper shakers. The tricky parts is getting the dimensions right, but I sacrificed a plastic binder cover to make templates, and used a pair of calipers to check dimensions. I had less shrinkage to deal with, because I'm using white earthenware (necessary to get the proper glaze colors), and since there's no shrinkage between dry and glaze fired, I can actually adjust measurements by sanding if necessary.
The flanges were a little trickier. Center the clay, open again down to the wheel head, spread the clay out. At the correct width, split the clay, with some coming up to form a short cylinder, the rest moving out to make a flat skirt. Again, check measurements with calipers for diameter, ruler for height, and template to set the curved transition. Made three to cut six, and used a fourth, unsuccessful attempt to calculate shrinkage (Marking a six-inch span that I'll then measure at leather hard.)
I created a template on the computer to show me where to cut down the thrown pieces, sized using the shrinkage from above. I centered each piece, using the bulls-eye circles on the template, and using a combination of eye-balling and ruler, and a very sharp fettling knife, I cut six half-square flanges out of the three originals. Now it's time to dry, while I chip out broken bits and compare glaze samples. I'll be using commercial glazes from Georgies, I think, rather than trying to mix my own.