Besides catching up on some sleep this long weekend, it was high time I put the new large clamshell kiln through its paces. It fits a 23x23 kiln shelf, which for me is pretty big -- that's nearly 4 square feet (and 14 inches in height). The bright and shiny kiln was just waiting for me to get it programmed and press START.
Yesterday I spent about an hour cutting 1x3 strips of ripple dichroic glass with either clear or black backgrounds, for some cool pendants. These are simple and effective and fun to do. Besides, it would also give me an idea of how my kiln works from a mapping perspective (were there hot or colder spots throughout the shelf). I was grateful to learn that the kiln heats evenly. That learning didn't come without a little bit of trepidation!
I filled up the kiln shelf, got everything ready, closed the kiln down, and fired up my program which would slowly bring the glass up to 1450, then ease it back down from a full fuse. The clicking of relays was happening, the temperatures were going up and up! Just how they are supposed to! Yay! The kiln got to 920 about 4 in the afternoon and never seemed to get any higher. It was at 940 after 9:00 p.m., not nearly hot enough, and I shut the kiln down. It should not take over 9 hours to get up to temperature. I would deal with it in the morning...
All night I kept thinking -- is it just the lid elements that are working? If that's the case, it's not nearly enough to bring a kiln that size to fusing temperatures. What if it were broken? It's simply way too enormous to ship back for repair. Where does someone get on-site kiln repair? The thoughts kept swirling, but I had a plan for the morning.
At 8:30 this morning I found that the kiln was still at 220 degrees (while turned off) -- pretty good insulation! There was a PF on the controller display (which isn't discussed anywhere in the book). I re-programmed the kiln from a slow to a medium speed fuse, and pressed GO. The clicking began again like yesterday -- it's a good sign -- but would it get up there?
700, 800, 900, 1000 degrees and climbing. 1050, 1080, 1100! It was working! SCORE! It made it up to 1450 easily, the glass was fusing beautifully. This particular kiln has a quartz viewing hole in the side allowing me to peer inside with a flashlight to see the glass pieces -- very cool! Even with the flashlight off, the orange glow of the elements and firebrick were eerily seductive! It was at 1450 for about 10 minutes and the effect on the pieces was reached, so it was time for things to start coming down.
I vented the kiln down to a 1000 degrees, then closed it up again to finish the annealing cycle. You have to imagine, it's 1:30 in the afternoon -- a VERY warm summer afternoon in Los Angeles, hot radiant heat coming out of the Behemoth, the other tabletop kiln going for the torchworked marbles and spheres I was making... HOT HOT HOT!~ I am so going to enjoy this more when it cools off!
The kiln is now down below 200 and I opened the lid to look momentarily, and the dichroic treasures were waiting for me there. The best part is that the kiln didn't lose but about 10 degrees of heat for the moment I opened it. It came back up to 190 easily and by the morning, the pieces will be room temperature and ready to go!
I would normally use a coated mandrel to make a long bail for the pendants, but this time I'm going to epoxy on silver bails and go with it. From what I saw in the kiln, I have about 40-50 pieces that will be good to sell! I like this process a LOT!
Honestly, I still stand amazed at the incredible medium that is glass. It's truly the best!
Sunday, July 5, 2009
Thursday, June 25, 2009
DAP Chemistry...
I have been experimenting more with Double Amber Purple (DAP) from Northstar Glass. Though working with borosilicate glass (boro) for over a year now, getting used to the chemistry of boro is exciting and a challenge.
Over the last few years, soft glass (System 96 flat glass from Spectrum and Uroboros), had been my medium of choice in torchwork, and the relative delicacy of soft glass has always been in the forefront, especially when it comes to heat. Granted, some of the S96 glass has been wonderful in the torch, and for the life of me, can't seem to scorch or burn it, most requires a gentle hand when it comes to heat. Boro is just the opposite!
To be able to work a glass piece and not have to worry as much about shock is incredible! The best part, and the most challenging for me, is getting (and keeping) the glass hot enough. I loved the pictures of DAP (and when I used it at the Mazet Studios last year, loved it) but when I used it in the torch, the amber side was the only one that showed. It wasn't until I saw Brent Graber's video (Hi Brent!) that he talked about heating the hell out of the glass. The elements needed to align with heat, and to heat and heat and heat the glass, then heat it some more!
Wow -- he is so right! I will use DAP rod and frit, and get the glass white hot in the torch. Then while trying to keep it from falling into a molten glop, keep it heated. The purples are outstanding! I will flame strike some of the piece, as possible, but the purples just pop! In order to experiment (and to save on the pricey boro), I have been heating clear rod and rolling it in several layers of DAP frit (large) then heating it like I've described. The results are really fun, and I'm looking forward to doing some marble experimentation with this.
I had to laugh, as I stood at my torch the other night heating the hell out of the DAP, I imagined what my soft glass would look like (what shades of pukey grey they would turn) if I were to incinerate that glass like I was doing the boro! Too much fun!
Okay, yes, I'm now a complete and total boro whore -- BoHo -- and look every day for the %age off emails for my new boro faves (and especially the now beloved, Double Amber Purple!).
Over the last few years, soft glass (System 96 flat glass from Spectrum and Uroboros), had been my medium of choice in torchwork, and the relative delicacy of soft glass has always been in the forefront, especially when it comes to heat. Granted, some of the S96 glass has been wonderful in the torch, and for the life of me, can't seem to scorch or burn it, most requires a gentle hand when it comes to heat. Boro is just the opposite!
To be able to work a glass piece and not have to worry as much about shock is incredible! The best part, and the most challenging for me, is getting (and keeping) the glass hot enough. I loved the pictures of DAP (and when I used it at the Mazet Studios last year, loved it) but when I used it in the torch, the amber side was the only one that showed. It wasn't until I saw Brent Graber's video (Hi Brent!) that he talked about heating the hell out of the glass. The elements needed to align with heat, and to heat and heat and heat the glass, then heat it some more!
Wow -- he is so right! I will use DAP rod and frit, and get the glass white hot in the torch. Then while trying to keep it from falling into a molten glop, keep it heated. The purples are outstanding! I will flame strike some of the piece, as possible, but the purples just pop! In order to experiment (and to save on the pricey boro), I have been heating clear rod and rolling it in several layers of DAP frit (large) then heating it like I've described. The results are really fun, and I'm looking forward to doing some marble experimentation with this.
I had to laugh, as I stood at my torch the other night heating the hell out of the DAP, I imagined what my soft glass would look like (what shades of pukey grey they would turn) if I were to incinerate that glass like I was doing the boro! Too much fun!
Okay, yes, I'm now a complete and total boro whore -- BoHo -- and look every day for the %age off emails for my new boro faves (and especially the now beloved, Double Amber Purple!).
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