Ron Roy on mon 13 sep 99
It is not my intention to critisize or flame anyone - I appologize for any
discomfort I am causing here but,
This glaze has a lot of MgO in it - MgO has a low expansion rate compared
to other fluxes.
This glaze has a very low expansion rate and will be the cause of pots
cracking when applied to the inside of pots made with many clay bodies.
It's not hard to check - just glaze the inside of say a tea pot shape and
fire away. If you wana make it an even better test - put it on the inside
and put a crazing glaze on the outside.
If they are not cracked when you open the kiln - freeze em for a day - if
they are still in one piece pour some boiling water in em - in the sink in
case they crack so you don't get burned.
If they are still in one piece - sell it.
Let me say this again - this glaze has a very low expsion/contraction rate.
> . It is an opaque waxy glaze
> Soda spar 27
> Ball clay 7.5
> Gerstley borate ll.9
> Dolomite 8.7
> Talc l9.6
> Flint 25.2
93 Pegasus Trail