Would firing PMC in glass kiln cause reduction later?

[dusty]

I found some old threads on this, but it was before people were using silver glasses so much.

Will firing PMC in my glass kiln will leave it with a reducing environment, so that silver glass gets reduced when annealing later?

[Lisi]

Good question, and I was wondering about the same thing.

[wdgross]

This question has also just come up in our household. I'm using an Arrow Springs kiln for beads and Mary is looking into making metal clay pieces.

Is it OK to use the same kiln for the two different media? Each with their own firing program of course. Mostly I'm wondering if the metal clay and the carbon 'stuff' that's used with some of the clays will effect the glass in anyway.

[echeveria]

It should not. I asked that question via Tim McCreight to Barbara Becker Simon who replied that she uses the same kiln for both pmc and glass beads. I trust her expertise on the matter.

[Deb L]

When I was fusing it was always said never use the same shelf to place glass as you used for pmc. So maybe you'd be ok if you put a good barrier between your beads and the shelf, such as fiber blanket? Supposedly whatever residue is left on the shelf from the pmc can leach into or on the glass. I am no expert but that was what I was told on warmglass.com.

[bob]

I agree with Deb. I have never done it myself but read alot about not using the same shelf, it will affect what you are fusing. Again that is from what I have read and not from experience.
Bob

[theglasszone]

I have a Paragon SC2BD; I've fired tons of PMC and made thousands of beads, all annealed in the same kiln. I even have it set up as Program 1 = Annealing, Program 2 = PMC Firing. I've not had any cross-contamination problems ever...just saying!

[echeveria]

I do think that the rumor of a problem gets too much weight vs actual experience! Every time this question comes up nobody can cite personal knowledge of a problem.

[lindag]

I remember many years ago there was a thread about cross contamination on the old SGB website. Someone had experienced some fuming problems on glass and was concerned about PMC. This was right after PMC came out, it was the high temp stuff - maybe that made a difference. She had fired PMC and then annealed her beads. I can't remember her name but I believe she made beads of puppies in flower pots? It was a recurring problem. My memory isn't as good as it used to be so I may be wrong. Also, I don't remember what the final determination was. So, I'm no help at all, lol.

[dusty]

Does anyone who has tried this use a lot of silvered glass and leave it exposed on the surface? Normal colors aren't near as sensitive.

I think I found the thread you were talking about Linda, but it was from about 10 years ago, before people were using the silvered glasses much.

[Darlene Balkcum]

I've used my arrow springs kiln for glass beads, double helix glass beads, pmc and clay bowls (pottery) and I haven't had any problems with lingering residues causing any problems with my glass beads.

[RevDan54]

I too use a Paragon SC2BD and I have used it for all PMC, fusing, and annealing beads. No problems whatsoever!!

[saraconklin]

i have a chili pepper and want to do metal clay, is it possible if i got some fire brick to sit on top of the fiberglass blanket bottom? will it go to 1600 degrees? is there an easter bunny? thanks in advance

[echeveria]

It gets hot enough for PMC+ and PMC3. You can get a firing shelf that would do fine. My concern would be the fiber that sluffs off the top and sides. I don't know for a fact that it would be a problem though.

[jaci]

I've done pmc in the chili pepper. It was just fine. We have a piece of fiber brick in the kiln. I didn't have any sloth-ing issues but we only used one cycle. So not sure how the fiber would fare long term.

[2xMI]

Check the rating for your chili pepper kiln. Mine is only rated for 1100. Chili peppers are usually just used for annealing (unless they've changed in the past 8 or 9 years since I bought mine).

Mimi

[saraconklin]

thanks for the input. maybe somebody who has done a lot of pmc in the chili pepper will respond and then i will have all my questions answered.

[saraconklin]

Jaci: thank you for your tutorials, just found you. really nice that you give back. Sara

[jaci]

Thanks I love sharing glassy fun stuff!

[saraconklin]

Chili pepper goes to 1100 so not good for a real solid melt which i understand to be 1600 for 2 hours. I got an email with kiln suggestions from the Jen-Ken people. if you would like a copy of said email please send me an email at mountainbead at gotsky dot com

[echeveria]

Sorry , I misread your question as a statement re: how hot the Chili Pepper gets.

Google the firing schedules for PMC and Art Clay. Are you wanting to do silver? PMC3's lowest firing temp is 1100 for 30 minutes, so just a bit higher than your Chili Pepper is rated. It may be that you actually achieve 1100, but you have no way of knowing without a pyrometer to check your calibration.

Cool Tools website has an EXCELLENT discussion of minimum vs. ideal firing times. You can fire at minimum temps/times, but it is not ideal.

[jaci]

My chili pepper goes to 2000 on the pyrometer.

[eregel]

The thing to understand is that there's a big difference in the strength of the finished piece between minimum firing and optimal firing - cool tools has a good write-up on it:

http://www.cooltools.us/The-Ultimate...ide-s/1219.htm