John Hesselberth on thu 25 may 00
I have finally been able to spend some time at Alfred Analytical
Laboratory to see what is happening in the area of glaze testing and to
take a look at some of the results. First, I was able to get a few sets
of results for which the info is complete enough to aid my research in
the area. I am pleased about that. I don't yet have permission to post
those so there will be a delay in getting them on my website until (if)
the people who tested the glazes give me permission.
But I also noticed some bothersome things during my visit; here is where
I will offer to help. Some people are testing for things, that in my
opinion, need not be tested for. On the other side of the coin, they are
sometimes ignoring things that, in my opinion, should be tested for. For
example testing for nickel in a glaze that doesn't contain it or not
testing for barium in a glaze that does contain it.
Unfortunately, as I think I have stated before, Alfred Analytical is not
well prepared to help on this. They are excellent analytical chemists,
but they are not potter/ceramist chemists. They really don't understand
what is in the minerals, frits and stains that we use. They, of course,
do understand the metal oxides that we used for colorants. But when we
give a glaze recipe that contains, for example, frit 3134, spodumenne,
nepheline syenite and mason stain 6600, they don't have a clue how to
advise you what to test for.
I have been on clayart long enough to have a good understanding that many
of us are not strong in chemistry and some are even intimidated by it.
Yet I know some of those same people want to know whether or not they are
putting stable glazes on functional pottery.
Please feel free to get me involved in any questions you may have along
these lines--both before you have your work tested and after you get your
results. I will look at any glaze recipe sent to me and advise on what I
would test for. I will try to do this in a way that helps you make
better use of your dollars when you do have glazes tested and, hopefully,
increases your understanding at the same time. I'm not here to be
judgemental about what you are doing--only to try to help you move
forward in a constructive way. I will, however, tell you about glazes
that I think may be questionable or that I would be uncomfortable using
on functional work. I, of course, will also ask your permission to post
your results along with the others on my web site--I assume you know that
was coming--but if you say "no", I will respect that.
So, please, take me up on my offer. I won't go into overload with a few
inquiries per week. If I do go into overload I'll ask for relief, but I
don't think that will happen. This subject has become very interesting
to me and your involving me will help me learn faster also.
John Hesselberth
Frog Pond Pottery
P.O. Box 88
Pocopson, PA 19366 USA
EMail: john@frogpondpottery.com web site: http://www.frogpondpottery.com
"Pots, like other forms of art, are human expressions: pleasure, pain or
indifference before them depends upon their natures, and their natures
are inevitably projections of the minds of their creators." Bernard
Leach, A Potter's Book.
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