[Clayart] Clayart Digest, Vol 50, Issue 43

[Snail Scott]

> On Feb 2, 2020, at 11:04 AM, ronroy at ca.inter.net wrote:
> A freeze thaw test could be done every day to see what would work…



Yep, I do this; just have to stick to a daily routine: Pull out each evening to thaw; return it to the freezer every morning. Or vice-versa.

The sample should reflect actual intended use: thickness, glazed/not-glazed, etc.  Boil (or soak for a few days), then seal in a ziplock freezer bag. No benefit to wiping it off; just bag it up. Freeze and thaw daily for months. 

Staying frozen for a long time is no different than being frozen briefly just once. Clay is stressed anew every time it re-freezes, and stress that does no visible damage after one cycle may still open up cracks that admit more water, then freeze and split further each time until serious damage accrues. Valid test results require a repeated cycle of freezing.

We are trying to simulate years and years of exposure, so as far as I am concerned, there is no such thing as too much testing. 

-Snail