RGFA RAY GROSS FINE ART

[RGFA RAY GROSS FINE ART]

Hello Ray Gross RGFA RAY GROSS FINE ART  I bought the Jupiter series stackable JD2945 Kiln from Rob Bettey Northwest Potter's Supply.  I like Rob, he's  the closest thing  to Customer Service that L&L has.

There are lots of good things about this Kiln.  However I THINK  the designers didn't really  think things thru.  It's Stackable w  Electrical Power Source/Controller Unit free standing. Rings plug in and out to stack large pieces.

It came with only 2 handles per section... even a weight lifter can't lift the sections w 2 handles...I POLITLY COMPLAINED AND they sent me 12 more handles... You really need 5 per section to negotiate the element ring over the 4' "TUBES of PAINT sculptures I make.

The Dyna trol PREHEAT  does not stop at 206-207°F... it just keeps on going.

Instead of stopping at 206-207°F and cycling for the stipulated time set...this malfunction just "exploded" 7 TUBES in a Bisque at a retail value of $73,500.00.

Rob says the kiln needs to run on 1 thermocouple and gave me the sequence to fire on the middle thermocouple. .. I can't see how this will make any difference the kiln interior is only 45" tall. Why did they complicate the design with  3 thermocouples..

I have an old EVENHEAT big Oval kiln it fires perfectly on one thermocouple... the JD2945 is only 18" higher. Heat rises its Physics.

I'm loaded up with 8 More TUBES of PAINT slow Bisque tomorrow  w 22 hour PREHEAT.

GOT ANY HELPFULL IDEAS. Thanking you in advance 

 

[Bill Kielb]

sorry to hear about your issues

Hmm, not sure I can help but the preheat has always worked for me and it should ramp at 60 degrees per hour until 200f, then stay there for as many hours as you set it. Did yours continue and fire to cone in less than 22 hours§? Correct offsets in your tcouples need to be in place though so if you have any negative offsets programmed I would say that is a programming error. L&L usually has positive offsets. I guess it’s possible the control has a defect but too hard to tell from your description really.

Three zones are better than one, kilns generally fire cooler top and bottom because of the heat loss through the lid and floor not having elements to offset.  Physics applies, it’s not just simply heat rises though. If you think single zone is better, set up your control that way, it is possible. In more than twenty years I have never seen single zone work better than three zones, in anything actually.

As far as a suggestion to be extra sure, for anything that large why not run a single segment program at 20 degrees per hour to 195 degrees for 22 hours (or 10 degrees per hour) to be absolutely sure before you bisque? (It will take about five hours at 20 degrees just to get there) keep an eye on it for the first few hours to make sure the control does not have a defect.

As far as the handles, more is great, I just use the two but am very fit even though retirement age. Get some help when assembling and disassembling comes to mind. It’s fire brick and steel, it weighs what it weighs.

L&L makes decent kilns IMO, so my hunch leans more towards programming and process. It’s just my impression reading your post though so apology  in advance if you find a defect of some sort.

Are you sure you entered 22 hours for preheat and not 22 minutes or 2.2 hours? If it finished in less than 22 hours to preheat and 12 hours to bisque, your preheat time was likely entered incorrectly.

 

[Pres]

I had a four section 23" diameter L&L that was four sections. Obviously smaller, and less cumbersome. However, as I was often lifting off the top level to load, I rigged up a pulley system with four suspension cables to a single cable that I used to raise and lower the top section. As far as the heating problem,  I am not familiar with the dynatrol controller, but believe that issues there can be overcome. 

 

best,

Pres

[Mark C.]

sounds like programming error to me  and not an electric guy much. Need to slow down the heat cycle

blowing upo work is no fun but its all part of the process. New equipment takes time to dial in

I never in my 50 years in ceramic  business count the work in dollars until it all done and sold. Wether I have a 35 cubic car kiln load with bad clay that I have to throw into the trash or forget to close the damper on a bisque fire  in same kiln and have to throw 2/3 of it away. Part of learning via the school of hard knocks.

The three zone thermocouples are a good thing for glaze firing for sure (i do not have but one) but I only bisque in an electric and thats rare even. The three zones keep a big kiln dialed in temp wise in a glaze fire 

As Bill say its needs to slow down. I would wait on firing more until you get this programing issue resloved-L&L is most likely closed until next year so waiting is a good idea  to call them-I do not know Rob Bettey but it looks like he lives in Bend Or which seems a far piece from Florida-maybe he can walk you thru the super slow program firing program you need.With big work you need to go super slow (I'm assuming Tubes of paint are large as you said) so slow is a key deal.

Wait until you get the program right other wise more blown up stuff and you will be even more unhappy

I will say in ceramics when its all working  well sooner or later it goes to heck no matter what.

heck I left that damper open on a 35 cubic kiln stuffed with porcelain this year (never done that before). It hurt tossing  most of that cracked ware away. But I hope to never do that again.

It looks like you do mostly large work so you know slow is the bisque schedule you need. You just need a slow program-sorry about the loss of work. No fun for sure

Neil is a L$L expert and should chime is soon about the slow program hopefully

Welcome to the forum 

[Roberta12]

13 minutes ago, Mark C. said:

I will say in ceramics when its all working  well sooner or later it goes to heck no matter what.

Hahahahaha.  Someone should put that phrase on a mug!   

[PeterH]

>The Dyna trol PREHEAT  does not stop at 206-207°F... it just keeps on going.<

I understand your angst, but do you really believe that?

7 tubes exploded first time and you are about to fire another 8 using "the same" controller settings?
- Careful (and recorded) use of "review prog" would  confirm that you programmed the preheat time correctly (presumably should be 22.00), and help in the event of another post-mortem.
- A carefully observed test firing to the lowest possible cone, preceded by a 10-20min preheat would be a quicker/safer way to see if the preheat option is working or not.
- Of course if the preheat ramp is too fast for your work ...

PS

If there is a controller fault, you will eventually need to make a problem report. So if you think there is a problem at least try to collect the evidence on this firing.

Carefully run the "review prog" and note down at least the preheat time (presumably should be 22.00).

Try to note times & temperatures at least:
- just before the calculated end of preheat ramp-up
- a little  while into preheat  (is the temp still only 200ish?)
- a while before the end of planned preheat.
- a while after the end of planned preheat.

If your kiln is within hearing distance, perhaps set the alarm to just over preheat temp and take a look.

[Min]

@RGFA RAY GROSS FINE ART, when you did your initial empty kiln firing to condition the elements did the controller fire correctly? 

14 hours ago, RGFA RAY GROSS FINE ART said:

Heat rises its Physics.

Kiln heats by convection at the lower temperatures then conduction. There is also heat radiation within the kiln. Up to around ^016 it is convection heating that is happening. Conduction is when the heat penetrates the wares, this is why slowing the firing towards the top end helps with even firings (or a soak at the top). Radiation starts with the kiln elements being the hottest thing in the kiln but as the kiln heats up the heat in the shelves and wares that is also radiated.

"I have an old EVENHEAT big Oval kiln it fires perfectly on one thermocouple..."

It would be fairly straightforward to replicate the firing schedule from your EVENHEAT to the new L&L. If there was more empty space in the EVENHEAT then slow the schedule down for the smaller L&L.

[Babs]

3 hours ago, Roberta12 said:

Hahahahaha.  Someone should put that phrase on a mug!   

Or write a bluesy banjo piece....Neil??

[neilestrick]

 

19 hours ago, RGFA RAY GROSS FINE ART said:

I like Rob, he's  the closest thing  to Customer Service that L&L has.

Rob IS L&L's tech help guy. Literally. If you call the L&L service line you get Rob. And yes, Rob is great! Plus all distributors are also expected to provide tech help to their customers, just like a car dealer does. I spend a lot of time providing tech help to my customers.

22 hours ago, RGFA RAY GROSS FINE ART said:

The Dyna trol PREHEAT  does not stop at 206-207°F... it just keeps on going.

Instead of stopping at 206-207°F and cycling for the stipulated time set...

The odds of a Dynatrol skipping the preheat program is low. Chances are there's something else going on. Have you confirmed that each of the jumper cords and thermocouples are connected to the correct sections? Please post the firing schedule you were using. Did the bisque firing complete at the correct temp?  Was the kiln at room temp when you started the firing?

19 hours ago, RGFA RAY GROSS FINE ART said:

Rob says the kiln needs to run on 1 thermocouple and gave me the sequence to fire on the middle thermocouple. .. I can't see how this will make any difference the kiln interior is only 45" tall. Why did they complicate the design with  3 thermocouples..

I'm not sure why Rob told you this. Did he say that it would solve the problem with the preheat, and if so, how? Can you give us more information? 3 thermocouples are there to make the kiln fire evenly. No single zone kiln will fire as evenly as a multi-zone kiln. The problem with running the L&L on a single zone is that is doesn't have graded elements, so the top and bottom may run cold. Again, give us more info about the firing schedule and we can probably help figure out what went wrong.

[Babs]

Septuagenarian here, when first learning to use a computer way back when you switched it on and went to make a coffee while it started up..., the message stuck on screen by teacher, " It's not the machine, it's the operator"

So maybe 22 mins instead of 22 hrs?

What was the length of the firing for this failed firing.

Make a kiln god, at least you have someone other than self to get kranky at.

MISTAKES are where learning occurs, dammit!