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Old 2010-06-30, 10:34pm
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kbinkster kbinkster is offline
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Join Date: Jun 24, 2005
Location: Spatula City
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I should make it clear that it's not just the flame splashing back onto the torch face, it is also the heat from the piece you are working radiating back to the face of the torch. I lump it all under splashback, but technically, it's two different things going on, the result being that the face of the torch is getting overheated and the hot metal grabs onto carbon, forming the embers.

Any time you see spikes when you are running shorter candles or working with sensitive glass, add more oxygen or take away some propane (with the valves of your torch - leave your regulator alone) until the tips round out. Some glass isn't too sensitive to the subtle difference, other glass is, but no matter what, those spikes show that there is uncombusted fuel in the flame. If you combine this with a hot torch face, you have a recipe for carboning (because hot metal grabs onto the carbon in the fuel).

If you are working a color that is not so sensitive to a fuel-rich flame (like clear boro), you can run your candles out further and have them spikier. It's o.k. if the flame is fuel-rich. If you are running your candles longer and work further from the face of the torch, you won't be overheating the face of the torch enough for it to grab the extra fuel.

Mary, I would suggest that you go ahead and set your Regalia to 10 instead of just 9 so that when you run your centerfire to where you usually like it and turn on the outerfire, you'll have a little more oxygen to add on to that centerfire (so you wont necessarily have to turn your propane down).

I think that the reason your centerfire is getting the embers when you run the outer, and not so much the outer, is that the centerfire is the part that is overheating a bit because it is starving a little for oxygen and when you have the big flame splashing back and/or a big piece throwing heat back onto the torch, that center part being the hottest part will grab more carbon and there is more carbon available for it to grab since the flame is fuel-rich at that point.

I would suggest that when you are melting something in that you move it back maybe another inch to start and see if that helps, and move back little by little until you find the sweetspot where you're still getting good heat, but it's not so close that the flame is splashing back onto the face or the radiant heat from the piece is cooking your torch face. You might even find that the flame is a little hotter further back than where you work now because the combustion could be more complete past that point.
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Kimberly
working glass since 1990 - melting it on a torch since 2002
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