Ooooops! Meltdown!

Well - it happens to everyone eventually. Either the kiln, or the operator, fails and ooops - the temperature goes too high and you ruin a kiln full of beads.

So it was inevitable that it happened to me at some point. And it just did.

I was just heading past the kiln, and I looked at the temperature as I went by, and instead of a temperature, it read:  "HTdE."

Hmmm. That's not normal.

Cracked open the kiln door - woo boy  - it's glowin' like Chernobyl in there. The beads have actually dripped off the mandrels, and melted into a big free form plate (proving that glass really does want to be 1/4 inch thick).

Not good. 

Ok, turn kiln off. Look again. The glass has flowed all over the floor of the kiln and the mandrel rests. The beads are one big puddle.

Nothing here is salvageable - let's try and mitigate the damage to my kiln.

Pull the mandrels out and put them aside - on something non-flamable, please!

The glass however - that's a lot of heat. Fill a bucket with water.

Pull the kiln rests out with the long tweezers, and take outside and dump into the bucket.

Inside the kiln, a few "cabochons" of glass remain - but some poking with the tweezers frees them from the floor of the kiln. Never did get around to putting on that recommended layer of kiln wash that all the books say you should put on the kiln floor for just such an emergency. Fortunately - the kiln floor was fairly dirty - which made it easier to get the glass off.

Here's some pictures so you can see the gory details.

These are the mandrels - sans beads.  :-(

My glass encrusted mandrel rests. Notice how nicely it goes with the autumn leaves?

 Pulling it out of the bucket.  A metal bucket would have been better, but I was in something of a hurry at that point.

See - it pays to not sweep out the floor of your kiln. You can see the accumulated flaked off bead release on the bottom of the glass. Once again, being lazy saves the day!

The error message, HTdE, btw - is High Temperature Deviation - meaning the kiln overshot it's target temperature by more than 100 degress. Possibly due to a stuck relay. I will be watching the kiln like a hawk for the next little while.

Or possibly because I accidentally turned the kiln off, restarted the program, and didn't give it time to establish what temperature it was at before telling it to Skip Step. Seems to me I saw this happen before - it just didn't matter because there was nothing in the kiln at the time.

So - give it a few minutes if you have to restart the program on the kiln, and never forget to check the temp occasionally - just in case.

Kiln Troubleshooting

Well - I'm back. Back from some serious time away from the torch and from glass. I think I would like to say that time spent at the torch is not deducted from your allotted days on earth.

Anyway - while I have many new insights on eldercare and aging - having spent a lot of hours staring in the mirror of my future - this blog is about lampworking - so I will save those insights - with the exception of the following: Do the things you love. Do them now. You might live a long, long time - and maybe you'll have another 40 or 50 years to do the things you love - but it would be tragic if you lived another 50 years, but were incapacitated and couldn't do them. Like arthritis robbed you of the fine motor skills in your hands, or you had the physical skills - but not the mental capacity to be trusted with a torch.  

So - as you might imagine - a break of some weeks and I was itching to get back to the torch. As soon as I could, I fired up the kiln, and went off to load the dishwasher while it was heating up. However, apparently my long break without my regular sacrifices of bad beads and exploding rods to the glass gods had angered them, and when I returned to my kiln, it was blinking a message for me - not the happy and warm message of 972 - my temperature of choice, but tcL - alternating with the distinctly chilly 74 of ambient room temperature.

D4mn.

I dug out the manual - which - in defiance of all expectations - I have read and do keep handy for reference. However, there was no mention of a tcL error message - but it did say that tcF was a "themocouple failure." Hmmm. Not a good thing.

I went to the Paragon website for more insight into the error message - and downloaded a newer version of the manual. (Here is a link to it - for the 4.0 controller - just in case you need it. )

The manual was very helpful, and said that tcL is "thermocouple lag" - which is 

The heating rate is slower than 9°F / 5°C per hour, and the actual kiln temperature is more than 100°F / 56°C away from the programmed temperature. The tCL alarm becomes inactive above 500°F. To return to the display, press any key.

Causes:

1. Worn or burned out elements, defective relays, low voltage, and defective thermocouple.
2. On kilns that use a portable controller, the thermocouple has fallen out of the firing chamber.
3. A bare spot on the thermocouple lead wires has touched a grounded object inside the kiln switch box causing the thermocouple to short out.
4. You have programmed a cooling segment temperature that is below room temperature.

I could eliminate 4 easily by checking the program. 2 was also easily eliminated - not a portable controller. As it had been working, and it hadn't been moved - 3 seemed unlikely - so something in the #1 cause seemed the most probable.

I held a lit lighter up near the thermocouple - and the temperature readout started to climb - ok - the thermocouple still works.

Checking out the elements was tricky - because it means sticking your head in the kiln - until my s.o. came along and pointed out that I could just use my cell phone camera - just take a picture and then look at the picture.

 

Good idea! The cell phone can also just provide illumination if that's what you need.

At that point - he got involved and unscrewed the controller and went at it with a multi-meter and determined that the relay had failed. I can do a lot of things - but poking around with a multi-meter and getting meaningful results is not one of them.

A quick phone call to Jean at Nortel had Paragon calling me back, and confirming the part I needed. A replacement relay was overnighted and hubby installed it - and I was back in business 36 hours from the initial failure.

Kudos to Paragon and Nortel for their outstanding customer service. I wish more companies understood that customer service is a value, not a cost! And thanks too to Dan for diagnosing and installing it! ;-)

Kiln Troubleshooting

A couple of weeks ago - I started to have trouble with my kiln. My studio is a room over from my office - and the kiln is out of sight from my desk - but you all know that distinctive click that the relays in your kiln makes? That sound carries a fair ways. So - I'm sitting here at my keyboard, it's early in the day, and suddenly - I hear beeping - followed by the kiln "clicking." (I have the Paragon F120, btw.)

Well - that's odd, thinks I, and I get up and go look. The kiln is happily sitting there, displaying "Idle" and the room temp. Ok - go back to work.

It took me a while, but finally, I caught it in the act - the display would come on full - lighting all the LEDs and giving me 88.88 on the readout, then it would beep, and then the relay would click, the kiln would heat up a degree, and then it would shut off and go back to idle.

Well - a kiln that decides to spontaneously heat up a degree doesn't sound like a good thing, - it might be habit forming and decide next go for 2 degrees, or a 100, or a 1000! So I shut it off and called a friend. She suggested that sometimes the fuse can be getting "weak" - and I should replace the fuse. Fuses are cheap, (replacements at Canadian Tire), so I did that. And thank you to whoever decided that the fuse should be easily accessible on the front of the kiln. Seriously - thank you. Hint. Put the serial number on the front too.

That appeared to stop the spontaneous turning on and off, but, to be safe, I left it off when not in use, so it's hard to say. It was a few days later that I managed to clear some time to actually torch - so I fired up the kiln - and it had been on an hour - when it spontaneously failed, all 8s readout - alarm beeping, and then when back to running.

Only now - when I checked - it was running program 01. Program 04 is my normal annealing program. (I think my rationale to use my most commonly used program buried down the list was that if someone comes along and randomly pushes buttons and messes up a schedule - they are less likely to mess up Program 04 than 01.)

Program 01, I have set up as a fusing schedule. So the temperature rapidly overshot my normal garaging temp, and started to shoot up into the 4 digit area. I reset the program, but the kiln continued to fail and reset itself to running Program 01 from the beginning. Ok - call it a night.

Next day - I talked to Paragon kilns - described the saga in detail - to which they listened patiently, and then had me repeat the conditions for the failure - to determine whether the lights on the side came on - which I hadn't noticed. (I realize now - the Program/Review/Run lights on the side were not well lined up with the holes they shone through - which made them difficult to see unless you duck your head down - so I have been pretty much ignoring them.) Once I knew that (all of them came on at once) - I called them back - and the verdict was - the digital controller board was toast.

Paragon overnighted a new controller to me - it was in my hands by 10 the next morning. It was the work of a few minutes to replace the controller. Hubby did it - it's electronics, so he finds it interesting. This is what he did. Unplugged the kiln. Took out the four screws holding the controller in place - the display and board came out together. Unplugged the wires from the left and the right. Plugged them into the new controller. On the sensor (thermocouple) side, he matched the wire colours to the blocks on the board - although he says this is not strictly necessary. Put in back into place, reused the screws to put in place. Plug the kiln back in. Well - actually - he also unscrewed the board from the display panel before discovering that the new board had it's own display panel, but you don't need to duplicate that step. ;-) I only mention that because you can see it in this photo.



Kiln reassembled and starting a test run.


Overall - it took longer to find a Phillips screwdriver than it did to remove and replace the board.

Paragon kilns - both the kilns and the company - continue to impress me. This kiln has been working flawlessly for about 5 years, and when I called with a problem, they were super helpful on the phone, and had a replacement part to me the next day.

I wish the whole world was like that: helpful, competent and efficient. What a nicer place it would be. ;-)