Hello all, I have been trying a bit of glass fusing as I love dichroic sparkly glass, but how do I get straight edges? Is tack fusing better? Help...
Hi,
I've just started playing with fused glass and found it really helpful to have a lesson/workshop (can't recommend Dawn Turner, Zeldazog, enough if you are in the Midlands) but if you can't get to a workshop have you had a look at the PDF helpsheets on Warm Glass or Bullseye?
I can read loads, search this forum but for me nothing beats sitting down with someone and asking loads of stupid questions and learning whilst doing it with someone who has the skills and knowledge. From what I've learnt so far, different things can affect edges from poor cutting (I'm good at that), the thickness of glass can affect the edges as glass likes to be 6mm thick and I think the fusing temperatures and even colour of glass can affect the way it behaves.
Karen
Thank you, I do plan to attend a course;at the moment I am a bit incapacitated following some surgery, but will book on once mobile again:-)
HI
I have been climbing the mountainous learning curve too! I have found that whilst tack fusing helps to keep original shape 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!
Can I ask why you want square edges?
Quote from: Lorac on November 11, 2015, 08:23:41 AM
HI
I have been climbing the mountainous learning curve too! I have found that whilst tack fusing helps to keep original shape 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!
The main thing that affects the best temp is the kiln you are using. They all heat up, let heat escape, cool down and where it is hottest is all different depending on your kiln.
Some kilns heat from the top, some from the sides. Some measure the heat at difference points in the kiln. Some lose a lot of heat from the sides and therefore fusing at the edge of the kiln is very different to the middle. Unfortunately it is all about trial and error in your kiln. It also depends on the glass. I find white is a lot harder than clear. Just reember to write down if it works for you. There is nothing worse than forgetting for temp is best for a tack!
Sarah's got it pretty spot on. All kilns, even the same brand, will vary, because of age and inaccuracies of the thermo-couple. Then there's the type of glass. A short hold at the lower end, a long hold at the higher end.
Obviously if you're using Bullseye, then their tech sheets are your best friend. They put a lot of time and energy into research and testing. With B/E I'd think 593 is too cool, that's start of slumping, which occurs lower than fire polishing.
If in doubt, test fire one piece - I'd suggest at the lower end of the range. If it doesn't fire polish enough, you know you need to up your temperature. It's the best way to get to know your kiln. Unless you've got a kiln big enough to fire a body in, it really won't cost you much, and far better to spend 50p to £1 on electricity than ruin a kiln full of glass.
Keep good notes and records of all your firings - colours used, thickness of glass, photos, programme, how many items in the kiln at once, what went wrong or could have been better, both the successes and failures. It's the best way to learn. B/E technotes are very good but as others have said, there are many factors influencing success.
It's also worth trying putting off cuts of glass onto your kiln shelf in different locations and seeing how even a firing is.