Life Lesson #1 from the Kiln: Patience

This blog post starts a series I've had on my mind for some time. It occurred to me that the kiln, in addition to being the tool to shape or melt glass, is often a great teacher for many lessons in life that I have to learn--sometimes over and over. Glass is no exception. So I will lay out a few "life lessons" illustrated primarily by kilnwork, and though there may be interruptions in the series, I think I have about ten or so lessons at least in my head.


Patience. It's so hard to come by. Do you know patient people? Do they amaze you with that patience? Or do they drive you nuts? Are you a patient person? If so, this post might seem self-evident. But I'm betting that in a society like ours that grooms us to want it all NOW, most of us are deficient--at least some or most of the time--in patience.


My recommendation to get more patience is to learn to work glass.


When I first started trying my hand at glass, the first wall of patience I smacked into was learning to score it correctly. This is no joke--it took me 45 minutes and some tears before I finally got a good score and break on my first piece of glass. To be fair to myself, I later figured out that the glass scoring tool that came in the beginner kit was far inferior to the kind most of us use. (I've since replaced all my class kits with decent scoring tools. And I've always wondered why most of these beginner kits start the newbie out with such junk. It's a good way to discourage people right off the bat, if you ask me.) But I did eventually get better at it--I had to--because that kit didn't come with much glass.


I worked with micro-kiln fusing for about a year until I could cook up a plan to buy a larger kiln. Guess what? Larger kilns require MORE patience. Why is that? Well, whereas the micro-kilns basically heat glass in a continuous run from room temp to fusing temp in 3 minutes or so, larger kilns do not. In fact, the larger or thicker the glass piece, the slower it needs to be heated. That's where the beauty of a computer-controlled kiln timer shines.


And, to my shock as a newbie, I learned right away that my large kiln isn't on all the time. The programmer basically heats glass in steps, called "ramps," with hold times required at each segment along the way. The same is true on the cool-down side, too. So what I realized very quickly was that glasswork went from a 2-hour operation to about a 24-hour operation. Below is a sample firing schedule for a full fuse of 2 pieces of Bullseye glass, approximately 10 inches each:


Degrees F/hr Target temp Hold time/mins. Elapsed real time

300 1050 20 3 hrs. 50 mins.

200 1150 40 1 hr. 10 mins.

100 1225 10 55 mins.

100 1250 10 25 mins.

150 1300 5 25 mins.

500 1490 10 30 mins.

No Pwr to cool down 950 60 2 hrs. +/-

100 700 5 1 hr. 35 mins.

OFF 100 or < --- 12+ hrs.


Glass takes a LONG TIME to cool, and the closer the kiln gets to room temp, the slower the rate of cooling per hour. But even when the kiln temp reads 100 degrees F, which is generally safe to open the lid, the glass can actually still be much hotter; this is because the glass is radiating its collected heat back to the kiln bricks. So sometimes, I have to wait for that below-100-degree reading to be absolutely safe.


But for the sake of simplicity and illustration, let's just total up the "Elapsed real time" column . . . and the patience-producing total is approximately 23 hrs. until I can open the kiln to see the project. And that's if everything went well the first time.


A recent example of when things didn't quite go as hoped was 4 Caribbean Blue glasses, which I slumped to a 4-inch drop. The original drop pictured below took about 50 minutes once the glass reached 1225 degrees F. That's a conservative, but average, slumping temperature, and it has to be slow so that the glass along the upper rims can "feed" the slump; going too fast (hotter) can cause the slump to separate from the rim and fall down into the kiln. You can see the progress from Top Left to Bottom Right.



But because not all areas of a kiln are exactly the same temp, the two glasses in the front didn't slump quite as far as the two in the back. Here's what each set of two looked like, with the Back pair first, and then the Front pair:


You can see that the bases for the first pair (the ones in the Back of the kiln) are more stable because they are larger. I wouldn't drink out of the Front two glasses (directly above). So . . . back in they went, for another 5 minutes or so at 1225 degrees F. (Plus the entire ramp up and cool down sequence--another day of waiting.)


But now, I have 4 usable glasses. The next step, or course, is the coldworking, where I get to cut off the rims and refine the edges to something that won't slice your lip. But thanks to a glassworking friend, I now have a small 8-inch lap grinder, which will hopefully save me some time . . . if the glasses will fit into the wheel space. If not, I'll be working them by hand, much like the process I described in "Gettin' Down to the Nitty Gritty" in November 2020's blog post.


So, take a class on glass fusing (such as the Beginning Glass Fusing with Micro-kilns class that I offer, an upcoming plate-making class, or some other), get the fever, buy a kiln, supplies, and glass, and get that patience you wish you had more of. I promise it will come.


11 views0 comments

Recent Posts

See All