i've cleaned out six years of BE scraps from my jewelry business, which has yielded pattern bars sufficient for about 8 plates 10" square. i need a little improvement in the high end of the firing so the sheet ends up a little flatter, and a little better fused.
as an example, slices are 1"x2"x3/8", arranged in a basketweave lay-up. i had the pattern bars shaved at a tile shop, so they are fairly true on 3 sides, and slightly untrue on the 4th side. after i arrange the pieces, i dam all 4 sides. these slices are NOT placed on a base sheet of glass. have filled some of the crevices (maybe 1/16") with white powdered frit.
it's the top end of the firing schedule that needs your help. i have gone to 1500, hold 20 min, with result that bottom is very good, top OK, but granular appearance in frit areas. i flip sheet and fire it again so top side gets more flattened.
am wondering if maybe i should be going higher than 1500, or using longer hold at 1500, to get a better fuse where the frit areas are? they are fused, but retain the fritty look, as opposed to disappearing.
these plates will be sandblasted, slumped into plain curved mold, and acid etched for a sand-washed finish. i'm think i'm close to a good looking fuse, but not quite there.
thanks for any advice about the top end temps. i'm not very experienced with solving this kind of problem. kitty.
Firing schedule help for pattern bar dishes
Moderators: Brad Walker, Tony Smith
Timely topic cause it just so happens today I finished a bowl doing what you're attempting now. What I did was lay up pattern bars in basketweave pattern on top of a 10" round sheet of clear. To tack fuse the whole piece and do a bubble squeeze, I damed the sides to hold the pattern tight and fired to 1300 for 1 hour. I let the kiln cool to about 1000, then removed the dams and took it back up to 1525 for 1 hour. Between the 3mm clear and the bars on top, I'd estimate the height to have been a little less 3/8". By removing the dams and taking to full fuse, the piece flattened to 1/4" and there were no gaps/spaces between elements. The finished "blank" was 11". I then slumped it.
...Kelly (whose back is now paying for the 4 hours of cold working this bowl).
...Kelly (whose back is now paying for the 4 hours of cold working this bowl).
TY4 reply, Kelly. i was thinking of going to 1525 or 1550, so i guess i'll do that with the next ones. the firing i did was pretty close to what i want, just a little shy, and i didn't know whether it needed longer soak or hotter temp. after these 8 or 10 plates are done, i'll have some leftovers which i might put together on a clear sheet as you did. thanks for your help.