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Venting PMC Kiln also how precise is this model?

I’m thinking of trying to work with PMC, and have been looking at the Rio 9 program model.

The first question I have is ventilation.

What is an inexpensive way to vent it?

Can I get away with wearing a respirator, and then clearing the room by opening a window?

If I do all my firing in a closed metal container with activated charcoal, does that make the task any easier?

Another concern is that from what I’ve read, with bronze there you have to be particularly prtecise with the temperature, with say 10 degrees. How difficult is this to achieve?

Thank you,

Jim Benson

It’s a very good kiln that keeps accurate temperatures and heating ramps! I use it for enameling and clay work.

I have an indoor workshop and I don’t ventilate other than having an open window nearby.

No fumes seem to be produced with any of the metal clays - except a little carbon dioxide.

Hi, Jim,

I have a typical bath exhaust fan in the wall of my studio for, among other things, the kiln. For me, the issue is proper venting if I use an organic material like plant material coated with metal clay or, say, lace. Any of these will burn away in the firing process. The fan is placed closest to my soldering station at benchtop level which appears to be adequate for the kiln so far, but my studio has windows on three sides, so the cross-venting possible within it might not be representative of another studio layout.

I also have our smoke detector mounted on a plank which is hung via zip ties from the ceiling so that I can put the whole detector outside the room if fumes build up; I then remount it later. And of course a fire extinguisher sits near one of the exits.

(Disclaimer: I am a safety freak.)

I’m sorry I can’t answer your question about charcoal-firing certain products.

Have fun!


regarding working with base metal clays, some have a smaller range between not sintering/sintering/melting. It is strongly suggested that you test the clay in your kiln and don’t assume that the clay will sinter if you have the “proper” temperature to sinter. Burning off the binders is not the issue, but the sintering process is. Test with a strip of clay at the suggested temp, then when cool, try to bend it. Keep notes for the future. Every kiln will run at slightly different temps according to the readout - some more than slightly different. Don’t put a lot of effort and time into a piece without testing - heartbreaks follow.
Barbara who is seeing snowflakes in the air on Vancouver Island

  1. All of the Rio kilns are Paragon Kilns and are extremely accurate.
  2. To ventilate the kiln: I have used an overhead kitchen vent system which I actively vent to the outside via ductwork (if you use one of these, make sure it is the kind that actually does ventilate. Some of them only filter the air and send it back into the room). You can also build in a fan into an outside wall and placed above and behind the kiln. . . a bit more expensive perhaps to do.
  3. Opening a window is passive ventilation, that is, it does not guarantee that the air will be drawn out. The wind can blow in as well as out. Wearing a respirator only works while you’re wearing it and without active ventilation, the stuff you don’t want to breathe is still in the room.
  4. Even in a closed container, you are heating charcoal, which creates carbon monoxide, which you DO NOT want to breathe. Ventilate.
  5. These digitally controlled kilns are accurate enough for firing fine silver, gold, copper and bronze metal clays. Eventually the controls will need to be recalibrated or replaced. I’ve been using my similar model for 13 years with no problems.

PMC, either the fine silver or the sterling, are non toxic, so ventilation can be quite basic. I have a large studio (600 sq ft and 12 foot ceilings) and don’t ventilate at all. the binder burns out at about 500-700F and has little odor and lasts about a minute. If you are at all worried, place your kiln on a wheeled cart and put it near a door or window when the binder is being burned. Otherwise forget about it. Rio has done extensive, scientific testing of fumes that come from firing PMC and anything at all toxic is something like one millionth of a part. no worries. Now, if you happen to be implanting some other material into your PMC piece or you build your hollow form around styrofoam or wood clay, then you might prefer to place your kiln in a ventilated, airy place for the duration of that material being heated. Use common sense. I have been using PMC since 1997 and have had no problems with venting, ventilation or toxic issues. Any respirator or expensive ventilation system is overkill. Relax and have fun with this amazing material.

Lorraine_J, why would you want to move the detector out of the studio when fumes build up? If the fumes are building up, it’s time to move YOU out of the studio, isn’t it?

I have always felt that, not matter how long it takes for the binder to burn out, if I can smell it, I don’t want to breathe it. So I ventilate.

If the smoke sensor is sounding because of a known material in the kiln, removing the detector to stop the noise makes sense until the room has cleared. And of course I wouldn’t stay in there. Umm, that’s common sense.

  • Lorraine

“Sometimes it is the people no one can imagine anything of who do the things no one can imagine.” - Alan Turing