Helena Leary-Heinz on sat 13 apr 02
> >given the shrinkage rates with PMC, how can I incorporate it onto a
> >ceramic piece without it popping off during the firing?
> You need to score the clay surface very well,
> to give 'tooth' to the clay/PMC connection.
> Snail
Hi Folks,
With all due respect, I would 'strongly' recommend a different approach.
The process I'm about to explain has several advantages. First, if you use
a clay that vitrifies higher than ^010 (1640* F) you want the clay piece to
be strong. Second, you have the opportunity to clean up the white film from
the PMC element prior to attachment (tumbling or wire brush), rather than
worrying about the PMC clean-up damaging the attached clay piece. Lastly,
if you want to glaze the clay part of the combination and want to use glazes
that melt above ^010 you're going to have to do so before attaching the PMC.
Here's How:
First, fire the ceramic piece to whatever extent that you're going to. Then
create the PMC addition separately, figuring up for shrinkage and estimating
the contours of the clay piece onto which your setting the PMC element as
closely as possible. Fire/smelt the PMC piece. Then, using PMC slip apply
the PMC element to the ceramic piece (no scoring is necessary or even
possible at this point). The PMC element can be touching a glazed or
unglazed surface, it won't matter either way. Then, ramping to temperature
slowly, so as not to cause the clay undo thermal shock, take the combined
piece to the lowest temperature called for in the PMC firing instructions
and hold temperature for the required time. These numbers will vary
depending upon whether your using PMC+ or Standard PMC (1650* F for 10
minutes or 1650* F for 2 hours, respectively). Again, cool slowly for the
sake of the clay part of the combination. When finished the silver slip has
formed a bond between the clay/glaze surface and the PMC element that is
permanent and sturdy without the cheating feeling of having used glue.
I have used this process in one of the PMC classes I took and it worked
wonderfully. For PMC additions like a silver rim around the lip of a cup
there are slightly different instructions which I would be glad to discuss
if asked.
For further information look up Deb Kaplan, she lectured at NCECA in
Charlotte about using PMC with clay. Also you can look up the PMC Guild or
PMC Connection on the web and find a list of Master instructors there.
Also, there was a gal in the PMC Connection booth at NCECA 2001 working with
Chuck who did some really stunning clay and PMC combinations in both
stoneware and porcelain. (Can't remember her name.)
Hope this helps.
Helena ~~
Artful Elements
"That which is to give light, must endure burning" Viktor Frankl
Ryan Kamp on mon 15 apr 02
"I have used this process in one of the PMC classes I took and it worked
wonderfully. For PMC additions like a silver rim around the lip of a
cup
there are slightly different instructions which I would be glad to
discuss
if asked."
Helena,
I would like to hear some information on adding a silver rim on the lip
of a pot. I have some mugs that would look great with this addition.
Ryan
Lake Stevens, WA
Bruce Girrell on mon 15 apr 02
Ryan Kamp wrote:
> I would like to hear some information on adding a silver rim on the lip
> of a pot. I have some mugs that would look great with this addition.
Wouldn't there be a problem resulting from the very high shrinkage of the
PMC? Or is that what the special instructions are about? If so, would you
mind telling us how it's done?
Bruce "Possible Mental Case" Girrell
Brant Palley NMCLAY.com on tue 16 apr 02
You can brush on PMC+ slip on the rim ov any pot, glazed or unglazed. Fire
to 1650 F and hold for 10 minutes. PMC is very adheisive and it will
shrink, but if it cant shrink in width it will shrink in thickness. After
firing it will need to be burnished.
see more info at http://www.Silver-Clay.com
Brant Palley
New Mexico Clay
1-800-781-2529
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