FIRE POLISHING how do you decide how hot how long?

Started by Lorac, November 11, 2015, 08:27:32 AM

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Lorac

HI
I have been climbing the mountainous learning curve of fusing schedules.  I have found that whilst tack fusing helps to keep original shape with jewellery, a higher temperature is needed to melt the clear cap over the dichroic properly. Dichroic can leave rough even sharp edges if not fully capped and often the 'cap' melts to one side of the piece rather than centrally.
So.... for what its worth...I am now aiming for the fuse to be good and then using a grinder to square off the edges and even to ensure sizes are equal eg for earrings etc.  Then I hope that a FIRE POLISH will smooth off the surface of the ground edges without changing the shape of the newly squared piece.
BUT ....and its a BIG BUT!  .I have been searching for information on fire polish temperatures and the information is very bewildering and i havent yet been brave enough to choose a temperature. CAN SOMEONE HELP?
Information out there suggests: 593 degrees Centigrade as the start of fire polish range, bullseye tech sheets say 677 to 732, the very helpful tip sheet on Frit Happens says the range is 650 to 750 and mentions a 630 with 60 minute soak time.
What I hope someone can help with it how to decide what part of that range to go for with small earrings and cabachons made of bullseye with approx 6mm depth?  Obviously devitrification needs to be avoided as far as possible but the 650 to 750 range of a 100degrees is big!  What effects the decision? Do smaller bits need less? HOPE SOMEONE CAN ADVISE and i will certainly post the results as and when i get brave enough to try!

GorgeousGlassGifts

Hi Lorac.
Your exact temperature for a fire polish will depend on your kiln, as all are slightly different. Through trial and error I've found that I get a good fire polish using the same kiln schedule as a tack fuse. The added advantage is that you can tack fuse new stuff at the same time as fire polishing wayward dichroic pieces.