Fused glass part sheets are a great way to add interesting elements to your glass art. They can include many colours and complex patterns, but sometimes you just want something simple, like a classic black and white design.
In this tutorial I’ll cover a very simple way to create two versions of a classic black and white fused glass part sheet. One is white on black, the other black on white.
While the technique I’ve used here is quite simple, you will see that things can go wrong and you still need to take care.
As usual, all the glass used is Bullseye COE 90, 3 mm thick, but of course you can use any brand or COE, just modify the firing schedule accordingly.
White on Black Part Sheet
The technique is very simple, and helps use up all those bits of scrap glass you have collected. In essence you simply place scraps of white glass on top of a sheet of black glass, then fully fuse.
In these photos you can see the piece after all the scraps were placed on the sheet of black, and after it was fully fused.
A couple of things to consider.
Keep the scrap pieces reasonably close together. Too far apart and the full fuse won’t be able to fill in between the pieces, resulting in an uneven thickness. You also need as much white on top as possible, to result in a 6 mm thick sheet, but with enough gap to allow the black to move up between each scrap piece.
Be sure to allow space around your piece so it can move. Placed too close to the edge of the shelf could result in the piece flowing over the edge, with disastrous consequences.
Black on White Part Sheet
With the black on white the process is exactly the same. Place scraps of black glass on top of a sheet of white and full fuse.
But, as you can see in the gallery photos above, there is something else to consider, that I didn’t. The end result was the white bottom sheet cracked apart with some force during the ramp up. The fact it cracked on the ramp up can be determined because the edges of the white sheet have rounded during the full fuse, hence it cracked prior to the fuse. If it was after the fuse the edges of the crack would still be reasonably sharp.
So what went wrong? Here is what I think.
Because black glass softens and fuses much faster than white, I believe my hold to release the tension within the glass was fine for the black bottom sheet, but too short for the white bottom sheet. In the black on white part sheet the tension had not released before the temperature was ramped up for the full fuse.
I do believe that a longer hold period would have avoided this disaster. Not that it’s a complete disaster as it is only a part sheet and I could still cut the elements I needed from the fused sections.
The adjusted firing schedule can be found below.
A Near Kiln Disaster
However, there is another aspect to this event that could have had much greater consequences. When the piece cracked, with force, it threw pieces of black scrap off the shelf and onto the bottom of the kiln.
Fortunately, my kiln had been dusted with kiln wash so there was no real damage. But it could have been bad.
So hope this has helped a bit. You could, of course, use this method with any colours, including dichroic glass, opal and transparent, iridised etc.
Any questions, please comment and ask. I will do my best to answer them.
Please be aware that all kilns fire differently and this schedule may not produce the same results in your kiln.
Full Fuse – 6 mm Part Sheet
|Segment||Rate (C/hr)||Target (C)||Hold (mns)|
3 thoughts on “Making a Fused Glass Part Sheet – Black and White”
I don’t understand the term “release” in your firig schedule. I know about the bubble squeeze, but not release. So the hold is at just undeer 1000F?
Hi Maryellen. Basically, the first segment is to get the glass to a temp where we have passed the risk of shocking the glass and cracking it. The hold allows the glass to get to the same temp throughout. I use the term ‘release’ to refer to releasing the tension in the glass due to variances in internal temp that may crack the glass. After this temp the glass starts softening and then you go up to a bubble squeeze. In some schedules they bypass this and go straight to about 670 C for the bubble squeeze, before then ramping up to full processing temp. It does depend on your ramp temp a lot. Many schedules I notice don’t stop at the release point I do. They go straight up to bubble squeeze. I have done this but had a couple of cracks so I introduced this ‘release’ hold and often bypass the bubble squeeze as the pieces don’t really need it. If bypassing this ‘release point and holding at the bubble squeeze temp works for you give it a go. Hope this helps.
Yes. Thank you very much. It really makes sense. On the black and white pieces, the longer release will allow the stiffer white to get closer to the same softness as the black before y ou take them higher and then lessen the risk of cracking from the uneven movement of the glass?
So much to learn. Thank you again.