I've remembered to share the final laugh at my expense on this subject. (I've already advertised my stupidity by admitting that I'd never thought of using these handles to >load< a kiln, only unload!). Sit down, it will take a bit of scene-setting - but it's a quiet day today here!
OK, a couple of years ago, I opened the kiln to find utter mayhem inside. Black soot covered everything, the shelf and the glasswork on there covered in a skanky black scum, strong smell everywhere. Good grief, what had happened?
Could only imagine the kiln had blown or something similar. Started phoning around and reached the manufacturers. They asked for pictures and were baffled when they saw them - never seen anything like it. They said that something combustible must have been inside the kiln but I found that so hard to believe - what could that be, there was nothing I'd done that could have caused this, was there? KC said to remove everything and to fire the empty kiln a couple of times to a very high temp and this would burn off all the black residues.
The shelf was still inside the kiln where it had fired so I now lifted it out and started to clear out the mess, ready to do the high-temp firings - but still baffled about the cause. Not for long though.
You may recall I made these lifting handles in order to haul out the shelf while still fairly hot and then to replace it with a pre-loaded second shelf and start another firing. What I'd done, as usual, was to lift out the hot shelf after the previous firing a couple of days before and pop it down to cool on a scrap piece of plywood nearby that I kept for the job. Then, a couple of days later, for this "black scum" firing, I'd lifted the shelf back up, placed it back in the kiln and loaded it with fresh stuff. No problem.
However now, when I lifted the cooled, blackened shelf out, I discovered that previously I hadn't actually put the hot shelf onto the scrap piece of plywood as planned - I'd put it down onto a scrap piece of Contiboard, the plastic faced cabinet material. I'd managed to fuse (ha!) the Contiboard scrap to the underside of the shelf, and hadn't noticed anything wrong when later placing it back into the kiln. I'd carefully placed the shelf onto its usual 4 little kiln posts, which beautifully protected the square of Contiboard hiding below. Yep, under the shelf, I now found a neat square of charcoal - minus its plastic coating, which was what formed the film of gunk now nicely deposited all over a batch of coasters!
Moral of the story is - play by the rules or face the consequences. Have a nice day!
PS: Kilncare were right - the high-temp firings did take a lot away and the rest has disappeared over time. The coasters didn't make it.
