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essiemessy 2018-01-25 1:51am

Paragon Caldera and 'Annealing' Collar. Not Annealing.
In search of anyone who uses the above for their beads and has checked them for strain.
My brand new setup is simply not annealing. It's not getting hot enough where the beads go, and beads are still showing definite strain after firing, according to my polarised lens testing.

The last run was as hot as 550C (2 hours with a 180C ramp down rate)which still wasn't hot enough to anneal. Another probe I have set up on the floor only read at approx 470C during that run. Borderline at best. There was a slight improvement over their supplied schedule results, but still unsatisfactory.

I've been trying to get a response from Paragon for the last week, since I supplied them with my test results and schedules as well as the specific model and controller info they asked for, with not a peep. The importer I bought it from is also keeping pretty quiet. What the hell?

To say I'm not happy is an understatement. I mean really, Paragon. Just talk to me. If they did, I wouldn't have to post stuff like this.
If I'm having this trouble, surely I'm not the only one.

Speedslug 2018-01-26 12:57am

Sorry you're having trouble Di.

My US American brain just doesn't do the C to f conversion well but google tells me you are likely running 96 coe or boro and I run to the softer glass.

I don't know of anyone that uses polarized testing but that only shows how little I know.

My only thought is perhaps the 'collar' is not seating very well and you have cooling air infiltrating and that is what is giving you fits.

Maybe try coating the matting pieces with kiln wash and giving them a thorough rubbing against each other to get the high spots smoothed out?

Next guess is longer soak and slower ramp down but I am just spitballing here.

Please let me know what kind of answers you find out.

I have always heard good things about Paragon customer service so maybe the polarized testing is throwing them off their game.

essiemessy 2018-01-26 1:31am

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Thanks, Phil.
Nope. Good ol'104.
The photo shows the test beads' position in the kiln, the beads, and their respective strain showing after the firing at the schedule supplied with the bead collar. Bearing in mind that the door is more than four inches below the element segment, and their schedule calls for nearly 40C more than the usual Effetre annealing temp, which doesn't cut it.
Hell, it's a long ways off if 550C doesn't either.

I finally got a curt response this morning, as it happens. I'd kept it quiet to be fair, but with no response, I had no other avenue but to ask elsewhere. At least they did, even if it took some public comment.
They're waiting to hear from other departments about it, apparently. That's great, but why not let me know that nine days ago?
I couldn't imagine such an established annealing kiln manufacturer not being familiar with polariscope testing of their firing schedules for strain. I would keel right over if that was the case.

Beads are a part of my business, and I can't see any other business being cool with being made to wait nine days for contact about a pretty serious issue in terms of expectations of the quality of my products. Especially when a couple of thousand dollars is involved.
They wouldn't stand for it, so why should I?

Results below:

Speedslug 2018-01-26 7:39am

My only other thought is making a higher rack to prop the beads up further into the warmer zones.

Yeah, 9 days is a bit of a stretch even with my own overly patient attitude.

Good pictures by the way.

Moira 2018-01-26 12:38pm

Hi Di,

I suppose the question is - is this about the temp being uneven through the kiln? So it's reaching the set temperature near the thermocouple, but not at the bottom of the kiln where the bead collar is. Or is the whole thing faulty, and not achieving set temp anywhere?

A bit of investigation with your separate thermocouple should tell you which. if it's faulty, you have evidence to back your complaint. If just uneven but reliably so, then it's just a matter of increasing the set temp.

I'm surprised Paragon are being so unhelpful. I contacted them once with a problem (with a second-hand kiln, in England!) and they were very obliging.

Good luck!

essiemessy 2018-01-26 1:48pm

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:lol: Thanks Phil re the photos :) . The very first firing's very poor results gave me a great picture - so good that I posted it on Instagram as every lampworker's nightmare or something like that. This is from carrying out their garage/anneal schedule to the letter, and it's only a little spacer bead.
That was when I knew I had a really major problem with something. Thankfully I have my own probe and pyrometer which pretty soon gave me the real story.

Hi, Moira :) Yep, the elements and controller thermocouple are working perfectly.
A test batch anneal fire with a shelf on props just below the bottom of the element collar yields good results, with a standard 500C soak, as if I was using my old kiln. It's just too far for significant heat to reach the full depth of the collar. And of course the bead door is redundant if the floor is unuseable.

As for Paragon, yes, I was surprised too. I certainly wasn't expecting that and with each passing day it was dawning on me that this problem was clearly a design fault and had some possible implications for the whole configuration options for this baby. But if it is really that serious (man I hope they come up with a solution - or find something really wrong I'm doing) and they've gone away to do some testing, then great. They could have told me that. They forget I know what my own results are, and fully expected them to come back to me with their own data and some possible reasons why my beads are no good.. Surely there are test archives buried somewhere.

I was perfectly happy to keep it all quiet in case the worst case scenario came to pass, but not without some support in the meantime. And with no support forthcoming, that just served to piss me off, in the context of one business working together with another in order to work on a solution.
And the eventual response I did get didn't suggest any willingness to do so either. It was pretty dismissive, thinks someone who was already disappointed that her new baby wasn't working, and just plain rude, thinks someone who has invested heavily in equipment for business purposes. My reputation as a worker is important, and the last thing I want to churn out is poor quality beads for people to enjoy.

The importer I bought it through here in Australia were not what I'd describe as terribly supportive either, unfortunately.

For now, all I can do is wait for the 'other departments' to get back to them.
I can't make beads in the meantime without a big hassle of getting my old kiln andaccessory probe set up again (have it packed to sell/move),or finding room for the crock pot to batch anneal.

I'm counting my blessings that I got this happening before our move, rather than leaving it all packaged for after the move in a few very short months. So it could have been much worse.

Three Muses Glass 2018-01-26 7:16pm

Oh Di. :( That's some pretty serious stress for such small beads. How frustrating! Do you have any fiber blanket to lay down on the bottom to maybe try and keep more heat in? Don't know if you could get beads in that door with an inch of fiber down though.
I agree on the design. Those collars never made sense to me on any model. Paragon isn't the only ones who sell annealers with collars.
I hope they get back to you.

essiemessy 2018-01-26 7:46pm

Hi, Rebecca :)
Yeah, it was enough to freak me out, that's for sure! And as it is I've got a thin shelf sitting on the bottom (can't be bothered kiln washing the bottom ;) ) for some heat retention, plus nice heavy posts surrounding it. Plus the probe with a nice heavy clay sheath. I can't do any more than that.

A friend has made an alternative stack of fibre board which will only be 40 mm rather than four-and-a-bit inches to reach to anneal. That should work. When it arrives in the mail I fully expect to be making and annealing beads in one hit without any problems. I just have to cut a bead door opening and stuff the gap between beads with another piece.
Thank goodness for her! She's helped me out more than once in terms of ensuring the beads are properly annealed with my big kiln, not to mention hands-on, face-to-face assistance.

But if I knew then what I know now, I certainly wouldn't have bothered with this kiln at all.

And I can't stress enough (pun intended :lol: ) the importance of lampworkers knowing how to test their beads.

Three Muses Glass 2018-01-26 7:51pm

What a good idea your friend has! I hope it gets you up and running. Just wish you didn't have to go to all the trouble for a new damn kiln though.](*,)

essiemessy 2018-01-26 8:00pm

Yes, and yes! LOL

essiemessy 2018-02-04 4:23pm

A bit of an update without getting into the ongoing BS saga re Paragon.

Unfortunately the shorter collar did not work. Not to 540C at least, anyway. I was not prepared to test further given the poor results at that temperature plus the two tests before that at 500 and 520 respectively.
In a nutshell, anything BELOW the element collar is not going to work except at ridiculously high temperatures, and even then the heat distribution at that distance is not likely to be uniform. Which is fine if the door is not going to be opened during the soak, but even then if certain glasses are used during the garage phase, it still might be problematic.
This is just my opinion, but I don't find that option at all feasible.

Those of you who have this setup and are satisfied the heat reaching your bead annealing area is sufficient, that's all well and good.

For those of you who aren't, there is a very easy solution if your lid is not attached to a hinge and safety switch. Simply put the annealing collar on top of the element collar, and something stable and appropriate for kiln conditions to prop a shelf to the level of the top of the element collar, thus creating a floor on which to put the mandrels through the bead door. And then test for yourself.

Unfortunately my lid is attached to the hinge and switch and would count as a modification worthy of voiding my warranty if I decided to detach it, so I'm not willing to go down that road. But we're still working on whether an additional lid on top of the bead collar will work. I'm extremely confident that it will.

Those with the plain, hingeless plonk-on lid could test this very easily for themselves :D

essiemessy 2018-02-12 6:50pm

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Update on testing.
I managed to work out a way to use the kiln with the "annealing" collar on top without modifying anything, with the help of a fibre board floor, using the base as a lid. Then making a metal stand and putting stainless steel wide mesh in as a floor and mandrel rack.

Unfortunately, it didn't work.

As Paragon told the distributor (without any explanation as to why except to say it's 'unnecessary and too complicated' - they're still at their helpful best) since my last post here, don't bother.

However, it would have been great for them to explain to me directly their reasons why, given the weeks of work I've already had to do to get this thing to work as advertised (It won't!), but clearly they're happy for me to keep on going to the time and effort to test for myself as a responsible owner of expensive equipment which they're not willing in any way to take the smallest skerrick of responsibility for, themselves.

Even at 560C, beads were still not annealed, so there was no point in taking it up to their 'opinion' of 595 'or higher' in that configuration either.

So please accept my apologies for my statement above in this thread where I really hoped and believed that it would.
Unlike Paragon, I'm cool with admitting a mistake.

They've refused to engage with me at all on this which I find to be in extremely poor form. Not only dishonest, but also super-arrogant.

So I wrote them a letter a week or two back, letting them know what I thought of that. Still nothing from them directly. That was when they responded to the distributor here in Australia (who was CCd), instead of myself.
As for the distributor, they are willing to take the kiln back for a full refund if I can't get it working to my satisfaction. I'll have to decide whether I want to work for hours at a time with a 600C benchmate, or not.

I just don't understand why they would send you your new kiln with such inadequate instructions, especially for an inexperienced glass worker to work to. Down the track the consequences could be, at best, incredibly stressful when a new user finds that their glass is not annealed after all.

THE TRUTH IS IT SIMPLY WON'T DO THE JOB if 'annealing' in that format is what you're after.

I can't believe this has been allowed to go on for 18 years! And I can't believe it hasn't been picked up by anyone else during all that time!
I do believe, however that Paragon knew as soon as I first got in touch with them, hence their silence and complete unwillingness to even have a conversation from day one.

So today, completely and utterly defeated and gutted by this whole pile of BS, I'm testing the original collar on floor config at 600C. I'll know tonight whether or not even that's sufficient to actually anneal my work.

essiemessy 2018-02-13 4:20am

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Surprise, surprise. A far cry from the stated schedule.
The analogue reading is for where the beads go.

Damning either way.
It makes a bit of a mockery of the popular declaration seen so often seen on bead sales listings which refer to beads having been 'digitally annealed' or similar.
Sadly, and it absolutely kills me to have discovered this, let alone to make it public, but all that statement means for this particular equipment (unless tests and related adjustments have already been carried out) is that the beads would have been fired using a digital controller, but have most definitely not been annealed.

According to the analogue gauge I should at last wake up to some properly annealed beads in the morning. No thanks to the people who should have had this sorted 18 years ago.

Three Muses Glass 2018-02-13 1:16pm

:jawdrop: Holy crap! That's huge. I know mine runs 10-20 degrees hot and I adjust for it, especially with silver glass. No wonder you've been having fits.

Is there nothing to be done to calibrate it?

essiemessy 2018-02-13 1:22pm

Apparently it can be done. However I don't see the point in recalibrating anything. I think down the track it would lead to all sorts of issues should memory fail or if the kiln is sold.
Best to keep 'it real'.

I can't stress enough that it's not the controller. They all have their own little individual rates anyway. It's working just fine.
It's about other places in the setup which need more heat to compensate. That's understandable, given their instructions saying anneal at 537 which is way past Ivory or White sag point in bead areas nearer the elements, or to be more specific, in my old kiln.
But it's just not enough to account for that particular setup. Nowhere near.
I've been using that analogue gauge for years in the brick kiln to ensure beads were annealed correctly in it. It's proven itself time and time again.
I'm about to test the beads I just got out this morning.

essiemessy 2018-02-13 4:44pm

Even 600 isn't enough.
Well, Paragon did say "...or higher". Looks like the annealing temperature reading on the analogue is still not enough to account for the kiln's poor efficacy in that position.
The kiln ramped up slowly for a batch firing, soaked at 600 (or 510 on the floor) for two hours, then ramped down painfully slowly at a rate of only 50C per hour to turn off at 420C on the controller which would translate to even lower on the analogue, which would have been well past the annealing range anyway.

That rampdown rate should be more than enough since it's already overkill.
Perhaps cooling at that end of the range is too quick taking note of the vast difference between the temperature within the element collar range, and what actually reaches the floor.
At this point I don't think the probe is far off the mark given its results in my other kiln over the last six years.

Also, apparently (I got this opinion second hand from the only people Paragon will speak to about this - the distributor) they go by the BE films to test for strain because the glasses lenses I use show more strain than BE.
I'll be interested to see if this is true. I have a pair of sheets on their way in the post to make a comparison.
But even so, strain showing up is still strain, and enough to give me my doubts anyway, especially since I've used the same equipment in my own studio for so long, and have been merrily making and using beads with nice clear results on my lenses.

This just gets weirder and weirder.

essiemessy 2018-02-15 12:25am

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Final Update.

I give up.

After 600C not doing the job (but an interesting development I discovered next morning - more on that below), I tried out a mind-boggling 640C. Which also failed, essentially for no other reason except it's a ridiculously excessive setting for the sake of a lousy 520 degrees Celsius. Unless little spacer beads are all you make. They turned out just fine. But I generally make bigger focals and sculptures more than little spacers. Most of my big focals are squished somehow, but I also make fully roundy ones which require more soak time.

Five weeks of almost continuous testing, every which-way including 'upside down', this little beast has beaten all the fun of lampworking out of me for a while. And I couldn't be madder. Or sadder :(

As for Paragon's claim of BE film giving a more accurate result than sunglass lenses, well I'm very sorry to hear that because it's quite true. But more damning. See pic below.

As for the little surprise from the 600C batch firing, well I could have been knocked over with a feather.
The distribution of heat in that collar is, IMO, incredibly uneven.
I had the batch beads kebabbed on bare mandrels and propped in a rack. One mandrel was in an upper rung of that rack a couple of centimetres higher, and the little spacer above the focal (opaque focal, unfortunately or I would have checked it) had tacked itself ever-so-slightly to the focal. WTF??

But beads below that focal (2-3 to a mandrel with a spacer at the top) were not annealed, despite the decent reading (510C) from the analogue at the bottom. Something is going on above the floor of the annealing collar where the temperature changes quite markedly. This firing was a slow ramp up, and two hours soaking of focal sized beads. Way above annealing temperature at one place, not enough (or not for a long enough time) in another. And really if a bead was going to tack fuse, at that controller temp, it should have also stuck fast.

Given the analogue reading (510C) for that firing one hour into the soak, all but the very biggest should have been annealed, but even the smaller beads further down the kebabs weren't. There was plenty of time for at least the 15mm and smaller beads. 3 hours for the 20mm beads would have done the job, but who knows what the hell is happening in that chamber? And what on earth could it do to silver and other reactive glass beads with a weird distribution or movement pattern going on in there?

The 640C firing was a garage session, in which all beads were soaked for at least a full hour, while the largest were soaked for the full two hours after being made during the ramp-up.

Granted, they could have done with another hour, or more, but really, who would sit next to a kiln blazing at 640 degrees for that long?
My sessions would typically last up to six hours at a time which is fine when your big brick kiln is running at a nice 510-520C in the far corner of the shed.

I bought this little one to have within a table's distance in order to just plonk them through the hole. That's great if you can stand to be in the same room with it for hours at a time.

Even then with all stuff I've just written (by all means challenge my findings, I don't mind at all, and the variables are huge, I have to concede), my issue is still that the stated schedule suggested by the manufacturer, and the way it's worded, is enough to fool anyone who doesn't have the means (or inclination) to test for strain, into trusting they've bought something which will do the job out of the box.

My conclusion is that I'm sorry, but it doesn't, in this instance. We place a lot of trust in manufacturers when we should be trusting our own investigations more.

There's no way I could trust this kiln to do a good job. I'm too old and too tired to have to be testing for all the types of work I do every time I sit down to make beads. Hell, all I've been using is plain ol' Effetre transparents and scrap clears.
Bugger effing around with my BE or boro all over again!
I'm done with this kiln, and with Paragon. They have treated me appallingly and I'd never ever recommend them to a new kiln buyer.

Arnold Howard 2018-02-15 12:16pm

Please do not think that I am questioning your expertise. I am only trying to help. I take it seriously when a customer is unhappy with our products.

Here are my stress test results using 1) Bullseye polarizing filters, 2) polarizing sunglasses alone, and 3) a combination of a Bullseye polarizing filter and sunglasses:

Have you contacted the glass manufacturer about testing their glass for stress?

Are you sure your pyrometer and its thermocouple are accurate? The analog pyrometers I've used have an adjustment screw that moves the needle in either direction. This can throw off the reading.

The temperature is lower in the collar than in the heated section of the Caldera. Compensate for that difference by programming the controller with a slightly higher temperature.

I wrote the "Annealing Glass Beads" instruction sheet that you posted above. My schedule was meant to be altered if necessary.

I'm sorry our customer service department was slow in responding to you.


Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA /

Arnold Howard 2018-02-15 1:27pm


Originally Posted by essiemessy (Post 4973891)
Hi, Rebecca :)
And as it is I've got a thin shelf sitting on the bottom (can't be bothered kiln washing the bottom ;) ) for some heat retention, plus nice heavy posts surrounding it. Plus the probe with a nice heavy clay sheath.

The shelf and posts in the bottom of your Caldera will absorb heat and lower the temperature there. I suggest that you remove the shelf and posts to reduce the thermal mass. The thermal mass requires energy to heat.

Did you replace the thermocouple in your Caldera with one that has a ceramic covering? If so, could you send a picture of it? The ceramic covering will slow down the response time of your thermocouple. I'm not sure if that would affect your results since you are measuring a temperature during an extended hold.


Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA /

essiemessy 2018-02-15 2:00pm

Well, thank you Mr Howard. Nice to hear from you.

As I said above, the variables are huge and of course anyone can make of my testing what they will. All I have reported is my own lonely experience.

Thank you for your further input for helping us test our beads using the films. That will help others.

Thank your for describing the responsibility I have towards my own customers as 'expertise'. However, you flatter me. Naturally it's about doing everything within my power to ensure my stuff will last as long as possible, not to mention the responsibility I have to myself ensure that any investments in equipment perform within reasonable parameters, with whatever resources I happen to have (or not have) at my disposal.

Thank you for your clarification of the different chamber temperatures. Perhaps we need to define 'slightly' a little less openendedly, however.

And yes, I became aware of the heat sink of furniture on the floor early on and removed it, barring the thin shelf. This information will help others, so thank you for that.

I did not do anything with the kiln's own thermocouple.

I'm sorry too. Your response is way too little, way too late for me.
This experience has been hellish and expensive, and I have no wish to put myself through any more.

Three Muses Glass 2018-02-15 2:56pm

Di, are they going to refund you? I don't even know what to say to all that.

essiemessy 2018-02-15 3:03pm

I was offered a full refund for the cost of the kiln by the distributor. Hopefully that still stands. Having shipping it back covered would certainly be nice, though. I've spent enough on this exercise.

Three Muses Glass 2018-02-15 3:07pm


Originally Posted by essiemessy (Post 4977132)
I was offered a full refund for the cost of the kiln by the distributor. Hopefully that still stands. Having shipping it back covered would certainly be nice, though. I've spent enough on this exercise.

Good. Money, time and frustration, you poor thing. I've felt bad for you reading all this. I hope they do kick in for shipping it back.

essiemessy 2018-02-15 3:28pm

Thanks, Rebecca :love:
I'll find out, I guess. I'll definitely ask the question.
I've removed the collar to do a final batch anneal so at least I'll have some useable beads from this whole saga, even if they're just plain test ones. Then I'll pack it all back up.

I'll need a while to get excited about making beads again, though.
We're packing to move, so it won't be until later in the year. I just hope all this is behind me by then.

ESC 2018-02-15 5:58pm

Di, perhaps it's not come to light before now because so few lampworkers are technically minded enough to check their beads with a polariscope to see if there's stress or not. Or not interested enough to go thru with all that, trusting the manufacturer to make a product that performs as stated. I am so sorry you've gone thru all this after making such a substantial investment.

essiemessy 2018-02-15 6:08pm

Thanks, Susan. Yeah, that's most definitely the case for so many of us. The only reason I learned to check was because I was using a second-hand china painting kiln for my glass, which didn't have a digital controller.
So with the help of a friend, I was able to use the analogue pyrometer to ascertain the right schedules and hold at the right temp for garaging, batch and soaks, and then test for strain.
It was a good grounding which has served me very well, and I'm so glad I knew already what to look for because I'd continue to test every now and then just to make sure.
Of course, in times like this, that knowledge isn't always a lot of fun.

I have heard from the supplier here in Australia and they're being fantastic. Some good news, anyway :)

ESC 2018-02-15 9:11pm

Well I'm glad the supplier is at least being fantastic. And yeah, my first kiln was a ceramics kiln, no digital controller, just a set of cones, and an analog temp gauge on the side. I too babysat my kiln for batch annealing for a long time. Wonder where my sunglass lenses went?

essiemessy 2018-02-15 10:44pm

Yeah, wasn't it a process?

Moira 2018-02-16 3:43am

I am very sorry to hear about all the trouble and annoyance you've had.

There was a thread on Frit-Happens (UK) forum a few years ago about the risk of prodding a mandrel up into a hot kiln element whilst annealing beads in a Caldera and electrocuting yourself - which I thought was rather overcautious, I mean how carelessly does anyone put mandrels into a kiln?

But this temperature thing is a much better reason not to use a Caldera for garage annealing. When you think about it, this is a kiln with the elements around the side, and a separate lid - which is bound to leak a little air. Then you add a collar with no elements below the heat, and with a dirty great air gap to set up a convection of cool air upwards. How can it possibly heat evenly?

I am surprised that your 'upside-down' arrangement didn't work, I thought that sounded promising. Still - it didn't.

I think the Caldera is a great kiln if you want to work with glass and ceramics, because of the higher but still controllable temp. So, fine for batch annealing. The collar (used closed) would be useful for increasing the chamber height for, say, drop vases. You could use the door to peek in quickly to check the drop.

But I think your (annoying but valuable) work shows that the kiln as designed is just not going to give a satisfactory bead anneal. You could at best use it to 'semi-garage' your beads to batch anneal afterwards.

I hope you find a better bench-top bead kiln. Despite your frustration with Paragon, I wouldn't discount their SC2 - used by many with excellent results.

Moira x

essiemessy 2018-02-16 1:29pm

Thank you, Moira :) I hope so, too.

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