Thursday, April 9, 2009

Epilogue: The Great Glaze Crisis of '09

Well, after making an exhaustive list of the possible causes for the glaze falling off my pots and onto the table -- a glaze I've used for 30 years and with which I'd never had this kind of problem. I finally, with the kind aid of Pete Pinnell (who generously responded to my query with a detailed list of possible problems), nailed down the problem.

One other possible issue, not listed in yesterday's post was that the label on my tub of bone ash had fallen off. So there was the additional, though unlikely, chance that I'd put in something other than bone ash. Thankfully, that wasn't it. Though Pete Pinnell informed me that bone ash can cause that kind of problem too (he also said he uses synthetic bone ash).

The problem was tin oxide. Yup. Over the years I had slowly converted the glaze from Ken Ferguson's original (with tin oxide as an opacifier), and had been using zircopax as a total substitution.

I wasn't aware of this, but as Pete Pinnell informed me, "...did you add more tin oxide? It is also quite fine and can cause a glaze to take up water (and therefore shrink a lot)."

I got some zircopax in this morning, made the substitution, and voilĂ !

Just as a little post script...

If I ever decided to move to California and take up acting in film, I would adopt the stage name "Beau Nash". And if someone asked me if I was synthetic, I would merely respond, "Of course. This is Hollywood."


  1. congrats on solving the problem... i wish they could all be solved so definitively. nice maple leaves above.

  2. Hey John!!! How are you doing? I had spent hours reading your website .. Nice work as always. Nice seeing that your doing well with the business still. You have always been so very creative (artistic) You should be so proud.