Hi! I am sooooo new at this. Just got my kiln and I have fused a few experimental pieces and tried slumping a 2 layer fused circle into a small bowl mold. Before starting the slump, I added some frit, etc. for more color. The slump was partially successful, but the frit did not fully fuse...just tacked.
1. Should I have soaked longer or hotter?
2. Now, what can I do with this bowl to get a deeper slump and a full fuse of the added frit, etc.?
3. My kiln is a Skutt GM1014 with 3 peeholes, but I find it impossible to see anything through the holes. How risky is it to open the lid for a peek during the soak?
You can almost never fuse and slump at the same time simply because the temperatures where you do these things are so different. Fusing temperatures run around 1450 - 1500, slumping occurs around 1150 - 1250. Typically you fuse first at a higher temperature, cool down the piece, clean it, then slump it. Go through Brad's tutorial on this web site and order his book.
Slumping temperature and time depends upon the type of kiln, type of glass, the glass thickness, and the mold size and depth. I typically keep around a fused plates that are flawed in some way (hate the color, design, bubbles I really didn't want) to test a mold before committing a good plate to it. For a starting point, ramp at 400-600 dph to 1250 and slump for 15 minutes. BUT it depends upon your kiln and other factors. Go through Brad's tutorial on this website and order his book.
You can peek in your kiln (and for something like drop-out molds you usually have to). Wear a heat protective glove (handles are often hot and a lot of heat will be released as well) - I've got a welder's glove that works OK and they are pretty cheap at Home Depot. Open the kiln slowly and smoothly maybe 4-6 inches and look in. I never keep it open for more than 1-2 seconds. Then lower the lid softly back down. The reason is that if you jar it, you can shake loose some firebridk dust or chips which will adhere to the glass. I rarely open the lid anymore, but that comes with experience.
For your partially fused plate, if it hasn't slumped too much, you can try fusing it again. Sometimes it fuses into an even circle, and sometimes not, but it is worth a try. I find that often when things go wrong, they just keep going run. Glass is an unforgiving mistress (master). Chalk it up to experience and try again.
I do have Brad's book which is most helpful. I just get a bit confused trying to meld information from the various books with the kiln manual and the instructions for the Spectrum 96 glass that I am using.
Lots to learn.
I will try to fuse the bowl again. Should I do this in or out of the mold?
If you haven't bought Brad's book (link above to the right) then I highly recommend it. It covers the items you are asking about -- with the benefit of lots of color picks.
Glass for fusing is expensive. A good book (or basic class) will more than pay for itself in saved glass Brad, btw, is our host here at warmglass.com.
To test new shapes, molds, etc., I strongly recommend getting some free used windows. Windows (float glass) does its stuff about 100 degees hotter than art glass but it will allow you to try new ideas that are way out there without much cost. Then if it works, try it with expensive and beautiful art glass. Of course, you may end up in the situation I find myself in, I have never used art glass because float glass alone has so many possibilities (I have only been at this for two years though). -Jolly
There is more to life than increasing its speed.-Mahatma Gandhi
If you have not had the chance to take a fusing class, I would recommend investing the time in a basc course. Classes are taught at Artistry Stain Glass in Scottsdale and at the Mesa Art Center.
If you are using System96, you can also use throw away glass from your local glassblowing shop. You can get some really wild combinations and effects that you cannot get from sheet glass... such as the nobbies the gaffer cuts off the end of a optic mold stuffed piece.
If you go this route, make sure you check to see if the glass "batch" is compatible with COE96. (Spectrum is, Spruce Pine is not).
Brad, btw, is our host here at warmglass.com.