Yesterday, during my blowslot, I did some tests, firing enamels that had been screen printed directly to sheet glass and firing decals onto previously blown forms.
I set up all of them in the pickup box and sent it up to 560 C, full speed. The sheet glass tests were all set up on a pastorale.
Firing decals onto blown forms:
The decals I made worked alright. I only used the parts that hadn’t smudged completely, and they came off the decal paper alright, except in some cases where drips of the cover coat had gotten around to the reverse side of the paper, which fused the decal to the decal paper in that place.
I put the decals on both the inside of the glass and the outside. They fired on properly in both positions.
Firing enamels on sheet glass on pastorale:
1. a small test, one layer, enamel up.
2. 3 layers, enamels facing up.
3. enameled sides facing each other.
I fired them all in the glory hole until the enamels glowed.
In all the tests I did with the sheet glass, the enamels seem to have fired on properly wether they were exposed to air or not, which I think means that in kiln casting, I wont need to have a separate firing for curing the enamels, and one for fusing.