Washing Kiln Shelves
Posted 13 April 2012 - 11:37 AM
Posted 13 April 2012 - 12:00 PM
Kiln Repair Tech
Owner, Neil Estrick Gallery, LLC
Posted 13 April 2012 - 03:16 PM
The only time I use a grinder is if glaze ends up on a shelf.
Posted 13 April 2012 - 03:39 PM
I like that.
Posted 13 April 2012 - 04:32 PM
Immediate Past President; Potters Council
Professor of Ceramics; New Hampshire Insitute of Art
Posted 13 April 2012 - 08:16 PM
If you have access to a decent sized air compressor.... try using an air grinder, with a flex disc, 36 grit. It's actually meant for Auto Body/Paint repair work. The sanding surface is very flexible, not hard. Doesn't take ANY of the shelf - just the wash and glaze. It takes very little time... The last time, my husband took 2 full shelves, and 6 half shelves down to the bare shelf in 30 minutes! However, please protect yourself.... the kiln wash flies off in chips with LOTS of dust.
Posted 13 April 2012 - 11:11 PM
Posted 18 April 2012 - 05:08 PM
for electric kilns, we use a 50/50 EPK to Silica - it works great and flakes off easily for a clean slate. it'll peel up if you get it built up thick or put too thick of a coat, but we usually just scrape them fairly clean and rewash at least every other firing. for cleaning up shelves I usually get away with a wide putty knife or carborundum rub brick and cold chisel for glaze spots. the difficult glaze mishaps or things that make it to the shelf get an air grinder with a 4" grinding cup head if I can't chip it off with the chisel.
our gas kiln wash is 90 alumina, 10 EPK, then add in 2% macaloid/bentonite and 1% CMC to keep it in suspension and make it nice and stinky this wash stays intact and doesn't flake up. we typically don't remove this wash unless something makes it though to the shelf or if a chunk comes off and makes an uneven surface - then i'll just sand it down with a rub brick or down to the shelf if need be. even then, it's not hard to take off unless glaze fused it on.
either way, if glaze gets on the wash - we remove it EVERY TIME. I have a nice trophy shelf that an unchecked glaze spot eventually ate all the way through to the other side and dripped!