WarmGlass.com

Hi,

We were trying to make a lot of dots to then apply to some plates. We noticed when we do full fuse of a 3/4"x3/4" square black glass (stacked 3 high) it fuses into a nice round circle. But we noticed if we do identical setup for White or red it seems like they all get jagged edges around the circle, definitely not smooth round circles. Any thoughts? Would you maybe use more glass but smaller size or is it just always likely to happen with those sorts of colors? We notice same situation when we do small circles too using 1/2" x 1/2" stacked 2 high.

Thanks
Cherie

Different colours have different hardnesses (for want of a better word) and may require more heat to break the surface tension and allow the glass to flow. Fire like colours together and watch until they round off. BTW, I would not call a stack of 3, 3/4" pieces a little dot. I would call 1, 1/4" piece a little dot. Opaque colours are always going to take more heat work than transparent, or clear.

Cherie Knopf wrote:Hi,

We were trying to make a lot of dots to then apply to some plates. We noticed when we do full fuse of a 3/4"x3/4" square black glass (stacked 3 high) it fuses into a nice round circle. But we noticed if we do identical setup for White or red it seems like they all get jagged edges around the circle, definitely not smooth round circles. Any thoughts? Would you maybe use more glass but smaller size or is it just always likely to happen with those sorts of colors? We notice same situation when we do small circles too using 1/2" x 1/2" stacked 2 high.

Thanks
Cherie

Black is a very "soft" glass, i.e., it softens and moves with less heatwork than other glasses, especially opaques and even more especially whites. More than likely your schedule is giving the black glass enough time to completely gather, but in other colors it's not enough time. In addition, opaques (light, especially) tend to drag a bit more and stick to the kilnwash, so that could also be affecting things.

The easiest way to test is to increase the time at process temps. It won't hurt the black, but it should make the other colors bead up properly.

(Edit: Sorry, Brock, didn't mean to duplicate--we must have posted about the same time)

No problem, lots of information is a good thing.

Thanks everyone for the quick replies. We will work to change our length. We had a full shelf with about 30 of these dots all different colors. Our firing schedule had been:

Segment Rate Temp Soak (Hold)
1 500 1495 .15
2 AFAP 900 2.00
3 AFAP 100 2.00

Thanks.
Cherie

Brock & Cynthia
Isn't a temp of 1495 hot enough for any colors?
This schedule seems off to me
Susan

There is no need to anneal these.......just turn the kiln off when you get the look you want.

Susanbuckler wrote:Brock & Cynthia
Isn't a temp of 1495 hot enough for any colors?
This schedule seems off to me
Susan

I take them to 1500 to be sure. Then I hold and look until done.
My schedule:

Full to 1500
Hold
Off

It's not entirely the temp--it's also how long you're at that temp. If the glass isn't fully beaded-up then you stay there longer.

Too hot, too long with opals leads to KW stuck to the bottoms. It's a nuisance to get it off even with enough equipment.

Jim

The Hobbyist wrote:Too hot, too long with opals leads to KW stuck to the bottoms. It's a nuisance to get it off even with enough equipment.

Jim

that's where scrap thin fire comes in handy.

Irid with the coating against the shelf for the bottom layer of sticky colors helps with getting nice rounded dots without having kiln wash stuck to the bottom.

If you get kiln wash stuck on the bottoms, just throw the bunch into a basin of white vinegar for a few hours. It'll fall off. I've got a gallon of vinegar that I've been using and re-using for a few years now.

I'm with Andy.....we have a huge box of Bullseye scrap shelf paper someone gave us and it is perfect for these!!