Extended hold at 1000F safe?

[Rob Caplan]

I misprogrammed my kiln this morning so it will get to the observation stage when I have a meeting I can't miss. My back of the napkin estimate is that it should be around 1000F on the way up by the time I can get there to reprogram it. Should it be safe to hold there a few hours then continue up when I'll be able to look or should I anneal it down and then restart later?

I'm using System 96 and am draping 7 inch disks over SS mixing bowls. They're one layer with frit contour fused on them. I haven't draped like this before so I know I have a too long hold time programmed at temp. My intent was to look and skip the excess time once the drape was done.

Many thanks!
Rob

[Bert Weiss]

1000 is above the strain point. Once you are above the strain point, there is no harm in holding. Devit tends to happen quite a bit hotter.

[Rob Caplan]

Thanks Bert.

I ended up holding a few hours and then was able to watch the drape. Good thing too: it slumped much faster than my before-added-time expectation. Next time I'll drop the temp some.

Now to get through the impatient time before I can get a real look at the results.

--Rob