[Marcia Selsor]

claclana, on 04 March 2012 - 12:50 AM, said:

YES!!
thanks for your data!!
Mark, I have noticed the lusters but didn't know about their toxicity and smell (and their prices) thanks!

Marcia: fume with flame work / torch? like silver fume, but fuming what?...or how?

Am I correct in assuming that high silica glaze with titanium dioxide, plus CuO can be the solution!? (or I am building a bomb here!!?)(I imagine that the black slip is to show off the iridescence even further, or does some contribution?)

THANKS!!!

google Biz Littell Vapor Fuming
Below is from Gary ferguson's Raku Newsletter.


* Glazing *

Vapor Glazing

There was a question emailed to me after last month's issue as to "What is Vapor Glazing."

So I did a little research and discovered an old issue of Clay Times - March/April 2001 that had an article covering Vapor Glazing by Biz Littell. His technique is named "Kosai ware" which means "hue of light" and involves the use of precious metals such as gold and platinum or special salts such as Stannous Chloride.

His process is to first bisque fire the piece, then glaze fire the piece to cone 04. Then the piece is fired a third time to about 1000F at which point the kiln is opened to cool down to about 800F. One to two tablespoons of stannous chloride crystals are quickly poured on the hot kiln shelf around the pieces (but not on the pieces). Then the kiln is closed for a few minutes to give the salts time to fume the pieces.

This colorant effect is more permanent that the standard Raku copper matte flashing effect.

These chemicals are apparently very corrosive so it is critical that the proper safety equipment is used - respirator, mask, gloves, etc.

[Idaho Potter]

As I read all your writings, it brought back to mind my university instructor, John Takehara. He did a remarkable series of pots (bowls bottles, jugs, tea service) wherein he used lusters. Started with gold and silver, but the silver tarnished to quickly. Switched over to platinum and added gold leaf to many. If he worked on the pots at school, he wouldn't allow anyone else in the studio. He was good about making sure no one would suffer from the ill effects of these metallics--except himself.

H would work--hunched over pot after pot--for hours, and never wore any type of respirator. After several years, friends and associates noticed that his memory was rapidly failing. When he finally passed, it was attributed to Alzhiemer's with damage also to his respiratory system. The potter's world lost a true master of the craft because the respirator interfered with his view (he wore glasses) and became too much trouble. His exposure was not for a prolonged time--maybe 3-6 years--and he went downhill rapidly.

Any of you who use ferric chloride (and it's cousins) or any lusters--be careful out there!