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I'm curious, how many of the people that post on here were working with fused or cast glass prior to the invention of digital controllers and digital pyrometers and what were your experiences during that time period of not having precise controls and fiber blanket was very rare as an insulation material. I'm wanting to compare those with my own experiences. Did any of you actually have real heating and cooling schedules for your work? and how did you control them?

Tom, for a period of time I used an old Paragon kiln that had a kiln sitter and nothing else. No pyrometer, no nothing, just the ability to fire to a certain cone temperature then turn off the kiln. It worked absolutely fine for fusing or slumping two layer pieces, I just had to do a bit of experimenting to find the best cone to use. The kiln would fire to the appropriate cone, then turn off and cool on its own. No real schedule other than that. I didn't have a lot of flexibility, but I don't recall ever losing a piece, so long as I limited myself to two layers (1/4").

I came late to controllers, and even when I had, I still used processes that required visual inspection of the work to achieve the results I wanted. I don't think there is ANY substitute for inspecting your work in the kiln under heat.

Brock wrote:I don't think there is ANY substitute for inspecting your work in the kiln under heat.

Brock makes a really good point. With the advent of controllers, it is common for people to fire pieces without having any idea of what's actually happening in the kiln. Firing without a controller requires a certain amount of peeking to observe if the glass is fired the way you'd like. Something is lost when you fire blindly, especially when you use a canned program that doesn't require any knowledge of firing schedules.

My first kiln was fiber and home made @ 1982 or 3. I got the plans to build it from Rich Royal, via Paul Marioni, late summer of 1982. I had an analog pyrometer, with a screw adjustment that could widely vary the reading. My primary task was painting on 3mm glass, so annealing was not an issue. I have a peep hole, so I could see when the paint glossed. I recall fusing Bullseye but probably 6mm. This kiln is still in service. Thinking about it, this would mean that it fired up AFAP. I don't remember any stories about that. I did have 208 power, and now it is on 240. Maybe I had some sort of rheostat? I was in my early 30's, memories are vague...

My dad was in the temperature control business so he got me an SCR relay, a setpoint controller, and a device called an analog events programmer. The programmer was hyper sensitive, so sometimes I'd push a button and everything would go haywire and get lost. It did allow me to ramp and hold. By 1990, I had a real digital programmable controller that I still share today between my 2 kilns.

I look forward to the next generation of controllers from Arrow Springs. Their controller will have a computer / smartphone interface, and have the software in it capable of making a simple SSR in to an SCR (turning on and off 120 times a second). This means you will be able to monitor and control it from anywhere there is a phone signal or internet access.

I certainly agree that learning to devise your own firing schedules was an invaluable experience.

fusing and slumping was the easy part, I wondered how people that were doing larger casting were actually achieving what they did. As I recall there was an article in Ceramics monthly about 1962-63 that had all the instruction for doing a lost wax casting in glass. I think the "plaster" was cast in a cardboard milk carton. Milk cartons had just started to replace the glass bottles. Did anyone here use the large plotting controllers that were used industrially? I know several who used those up until maybe 2000. I know Mark Peiser swore by them and we know what his castings sold for.
I used to use a timer from an old electric sign that was hooked up to a "range control" that was from an old oven control, probably a Whirlpool or GE. AS the sign timer had a pulley attached that turned and it pulled a wire attached to the oven control that slowly turned it down over a period of 12 hours.

Tom Fuhrman wrote:fusing and slumping was the easy part, I wondered how people that were doing larger casting were actually achieving what they did. As I recall there was an article in Ceramics monthly about 1962-63 that had all the instruction for doing a lost wax casting in glass. I think the "plaster" was cast in a cardboard milk carton. Milk cartons had just started to replace the glass bottles. Did anyone here use the large plotting controllers that were used industrially? I know several who used those up until maybe 2000. I know Mark Peiser swore by them and we know what his castings sold for.
I used to use a timer from an old electric sign that was hooked up to a "range control" that was from an old oven control, probably a Whirlpool or GE. AS the sign timer had a pulley attached that turned and it pulled a wire attached to the oven control that slowly turned it down over a period of 12 hours.

I was taught that Libensky had a kiln setup with shelves braced inside the elements on 5 sides, roof elements open. He would put sand on the bottom, then the mold, and then fill all the space around the mold with sand. He would heat the whole shebang up to casting temperatures and then shut off. The Russians were paying his electric bills. This is totally inefficient, but simple and effective. He was casting 42% or higher lead crystal.

There used to be controllers that worked on a cam that is attached to a clock. The cam could be carved to create a particular firing schedule. Partlow and Watlow made these. I never used one, as I was fortunate to have the first generation push button programmable controller.

I did pyrometers and manual controls for about four years before I got my first digital kiln controller. And yep, visual was the way to go. I switched to a digital controller not because the manual stopped working, but because the pieces I was doing (especially castings) wouldn't fit in my kiln, and were getting to be of a size where the firing would be measured in days instead of hours. I didn't have time (or inclination) to sit there babysitting a kiln, so I bought a bigger kiln with a controller to do it for me. I still checked visually at critical stages.

on my first kiln I did not know how much life would be easier with a kiln controller so my husband rigged up a drip irrigation system that would turn the kiln on at a certain time and go on and off and then after dinner I would put it to full fused and wear a kitchen timer around my neck and run to check the kiln visually when my timer when off. kind of funny to think about the old days.

I read the book, Kiln-fired Glass by Harriette Anderson and started fusing in 1976. Went to the West Coast on a buying trip with a local supplier & remember visiting Bullseye Glass when secrective rumblings about compatible glass was getting tested (but they didn't want to talk about it). My kiln controller used on-off timers used for lighting, and the pyrometer was huge - but I never used cones. Genesis Glass was struggling making beaver tails, and Spectrum was just starting up with the 'continuous ribbon'. The highlight was being taken out to dinner by Mr. Loo (of C & R Loo) where I couldn't read the menu - so I listened to what he ordered and repeated that...

Thank you for sharing some memories, Mark.
What a delightful story of Mr. Loo.
Joyce

I still cast in a controller-less 1930s ceramic kiln.

I use a biggish investment complete with glass reservoir. Heat to 850C (orange) afap, hold for a few hours, and turn off. Crack open to drop to around 550C, close up tight, throw over a blanket, and leave until cold - about 5 days. If its a lost-wax mold, I hold at 450C on the way up to burn off any traces of wax, and if it's wet, at 90C to dry out.

Tony