New L & L kiln

[Pres]

I fired my new L&L e28-3 last night with an empty load, bottom shelves in, and one upper shelf near top zone cone 5 self supporting at top and bottom. Instructions said to fire fast glaze to cone that was included with the kiln. kiln took 5.38 hrs. . .I assume 5' 38".  Temp went to 2187, 2186 and 2181. My way of thinking that is ^5 3/4. I suppose I could find way of making adjustments to that in the cone offsets, but if wishing to fire to cone 6 that would get me pretty much there to just use cone 5, I do believe that I have been firing my ^6 firings by hand to about ^6 1/4 or 1/2. Any thoughts here on adjusting or not adjusting?  Really excited about the graphic set up of the Genesis controller and the wifi with phone app capability. New world out there.

[GEP]

This is my understanding of the Easy-Fire programs (if @neilestrick has a better understanding, listen to him instead!). The Easy-Fire programs are using a “variable cone” meaning if the firing is extra fast or extra slow, the controller will automatically add or subtract some degrees of temperature from the cutoff, in order to compensate. It is calculating temperature + time, not just temperature. 

For example, if you used “Slow Glaze” which would take 8 or 9 hours, it wouldn’t have added the extra temperature to the end. Or, let’s say you’re firing with old struggling elements, and the firing takes 12 hours, the controller will automatically shutoff at a lower temperature. 

The user has no control of this. If you want to fire to a precise temperature each time, then use your own programs instead. (I use Fast Bisque for bisque firings, and my own programs for glaze firings). 

For a single potter studio where you have a lot of control and consistency about how the kilns are loaded, you don’t need the controller to make these decisions for you. I think it’s preferable to be in control of exactly when the kiln shuts off. I can see how it would make sense in a classroom situation where the kiln loads can vary a lot. 

So for now, I wouldn’t tinker with cone offsets. I would make your own firing program that copies the Slow Glaze to cone 6, but set the end point to 6 1/4 or wherever you want it. 

[Smokey2]

My instructions for the same kiln says to do a slow bisque firing to cone 5 (not 05) which should take 16 to 19 hours.

Leave the cone offsets alone and adjust the temps and the holds to get where you need to be.

My ^6 schedule

seg    ramp/h    temp    hold
1    250°    230°    20m
2    350°    1900°    
3    108°    2180°    15m
4    9999    2080°     5m
5    9999    1900°    20m

From my manual

Quote

The test firing is done very slowly, about 16 to 19 hours
total to minimize the inner and outer surface temperature
differences in the kiln while it goes through its maiden firing.
Also this will slowly steam off any moisture absorbed by the
firebrick during construction, shipping, and storage.
The test firing is done to cone 5 (about 2167°F) to vitrify the
special coating on the inside on the firebrick and to allow an
“aluminum oxide” coating to form on the element’s surfaces.
The coating on the brick helps to reflect the heat radiated
from the elements, strengthen the surface of the firebrick,
and help prevent dusting in the kiln.
The oxide layer on the elements helps to protect them from
the many contaminants found in many materials fired in a
kiln. This aluminum oxide layer will rejuvenate itself every
time there is an oxygen rich firing to a high temperature.
Going to cone 5 may also point out any problems with your
electrical service - like low or incorrect voltage or wrong
supply line wire size.
The elements will also seat themselves in the ceramic
holders - and any springiness you see when you first get
your kiln will be alleviated.
NOTE: Normally bisquing is done to cone 05. Do not be
confused by how the test firing uses SLOW BISQUE to
cone 5, even though normally you would use a SLOW
BISQUE to cone 05. The Slow Bisque program is used for
the test firing BECAUSE it is a long program. We want this
to be slow.
The test firing is done with the operator present as much
as possible. This is to be sure the kiln is heating up safely,
and that the heating kiln affects nothing else in the room or
the room itself. As for the operator being present, logistically
this may be difficult as the test fire is designed to take about
16 to 19 hours.
To deal with this a “Delayed Start” can be added to the test
fire program, allowing you to press START at say 5PM,
the kiln to start at say 8PM in order to turn off at 3PM the
following day while you are there. More detail on this a
little further on. You can also split it into two firings (see
instructions at the end of this sheet).

 

Edited April 16, 2021 by Smokey2

[neilestrick]

What did the cones show? Like GEP said, it's going to go to whatever temp it needs to in order to achieve the proper heat work based on the rate of climb. I wouldn't change anything until you do a firing or two, with cones, on the schedule you would normally use, which really shouldn't be the Fast setting. After a test or two you can then dial in the thermocouples or cone offset.

Where did you see the recommended firing schedule for the first firing? Was that in the Genesis controller manual or the main L&L manual? Like Smokey2 said, L&L's recommended first firing is a Slow Bisque to cone 5 with a 3 hour preheat. It could be that the Genesis manual, which is not written by L&L, is saying something different. 

[Dick White]

The Genesis section of the L&L manual is a reprint of the Bartlett document. It gives a first firing example of a fast glaze fire to cone 04 or whatever cone the manufacturer included for that initial firing, but notes one should follow the kiln manufacturer's instruction if different. L&L provides self supporting cone 5 cones for the initial firing, but also calls for slow bisque, not fast glaze. I doubt the kiln is irretrievably ruined because of fast glaze vs. slow bisque, but my understanding is that the L&L special coating on the bricks needs more that the 04 firing that Skutt (and others) specify. (And yes, you can get out the popcorn when the Skutt crowd starts arguing with the L&L new owners about this in the Facebook groups...) The only thing I would add, mostly for the general edification of anybody reading along here, is don't rely on exactly what happened in the first test firing of an empty kiln. A full kiln will respond differently. Use cones even with a controller to ensure that the controller and thermocouple are working together properly to produce a consistent outcome. After several firings to develop an average of different loadings, tweak the offset as needed to perfect the controller. Keep using cones forever as things will drift with age. Y'all get back to work now.

[GEP]

When I replace elements in my L&Ls, the instructions that come with the elements say to fire the kiln empty to cone 5, and no particular firing speed is required. Maybe the Slow Bisque to cone 5 is just for the first EVER firing in a brand new kiln, for benefit of not just the elements but also the bricks?

[neilestrick]

1 hour ago, GEP said:

When I replace elements in my L&Ls, the instructions that come with the elements say to fire the kiln empty to cone 5, and no particular firing speed is required. Maybe the Slow Bisque to cone 5 is just for the first EVER firing in a brand new kiln, for benefit of not just the elements but also the bricks?

Yes, it seasons the elements, sets the mortar in the lid and floor, fuses the brick hardener, etc in a new kiln. I like to go slowly with any new elements for at least 1000 degrees or so, so they're less likely to mover around and pop out.

[ECpot]

Congratulations on your new kiln!  I also just got my L&L 28S easy fire.  Did the test firing.  
I noticed after the test fire, my lid gap become so big.  I reattached my lid after adjusting the metal plate and tension bar.  
even with all the adjustment, I cannot get the lid to sit right.  It’s off balanced and won’t close.  Did you have any issue with your lid?

 

[neilestrick]

@ECpot make sure the main hinge rod, the one that has the springs on it, is sitting in the bottom of the oval holes in the hinge plate . Move the entire hinge up or down as needed to accomplish that. It won't close properly and can damage the top row of wall bricks otherwise. Be sure to latch the lid during firing.

[ECpot]

Thank you so much @neilestrick !  My latch won’t close and isn’t aligned...  

[ECpot]

37 minutes ago, ECpot said:

Thank you so much @neilestrick !  My latch won’t close and isn’t aligned...  

It seems like my spring rod is sitting on the bottom of oval.  What’s odd is, my lid is not sitting straight on top.  Is it normal? 

[Pres]

5 hours ago, Dick White said:

The Genesis section of the L&L manual is a reprint of the Bartlett document. It gives a first firing example of a fast glaze fire to cone 04 or whatever cone the manufacturer included for that initial firing, but notes one should follow the kiln manufacturer's instruction if different. L&L provides self supporting cone 5 cones for the initial firing, but also calls for slow bisque, not fast glaze.

"If your kiln is supplied with cones, the programmed cone number should match the cones provided, or you may use a cone of your own choice for the first firing. The example below is for a cone 04 firing, but if you use a cone other than 04, substitute that cone number in the programming." Immediately after this is the fast glaze fire menu in novice mode.

I guess I missed something somewhere in my reading about running a long glaze firing. I do not believe anything is damaged, but time will tell. As far as making adjustments I was just wondering, and I believe asking for opinions is better than trudging on without more knowledgeable help. This is a new world for me, but I am not without some skills.  I would think the manual would show a long firing for first firing instead of referring to a fast glaze immediately on the page for first firing????!!

 

best,

Pres 

[ECpot]

I am so sorry to post my question in your post, @Pres!  

[Pres]

ECpot, no problem. New kilns can be frustrating, as they are part learning curve. Hopefully we will both get some answers.

 

For those of you looking at my question about adjustments, I would think this cone is pretty spot on, maybe a little hot. I had two included with the kiln, so one was at the bottom of the top sections, and one on the floor shelves. They both look almost exactly alike.

[Bill Kielb]

Looks pretty perfect to me. To me if your glazes finish how you like, fast is fine. Slow is popular though.

Edited April 16, 2021 by Bill Kielb

[Bill Kielb]

45 minutes ago, ECpot said:

It seems like my spring rod is sitting on the bottom of oval.  What’s odd is, my lid is not sitting straight on top.  Is it normal? 

The lid seems rotated from the body of the kiln. Maybe backup a bit and show the lid and kiln with more context from a few feet away.

Edited April 16, 2021 by Bill Kielb

[Min]

Re new elements (in a new kiln or replacements), from one of the Kanthal Handbooks from the wire manufacturer Sandvik in Sweden there is this advice:

"Pre-oxidizing the elements is recommended for customers using their kilns at elevated temperatures (cone 6 and higher), or under corrosive or reducing conditions. To oxidize the elements, heat your empty kiln to a temperature above 1922F/1050C with the peep holes open and the lid raised slightly. Holding the temperature there for 6-8 hours will ensure thorough oxidation of the elements, but most of the oxide growth occurs in the first 1-2 hours. This procedure grows a protective oxide coating on the elements before the elements are exposed to any harmful atmospheric conditions. This procedure is usually only done once, but can be repeated as required if the kiln is fired under harsh conditions such as a reducing atmosphere (which actually removes the protective coating)."

 

[neilestrick]

@ECpot there are two holes for the bottom hinge rod. One for higher tension one for lower tension. Try the other hole. Also make sure your springs are the same- both with ends in the center on the top the other ends on the outside. Don't do one outside and one inside at the same position.

[ECpot]

1 hour ago, neilestrick said:

@ECpot there are two holes for the bottom hinge rod. One for higher tension one for lower tension. Try the other hole. Also make sure your springs are the same- both with ends in the center on the top the other ends on the outside. Don't do one outside and one inside at the same position.

The lid sat tighter with lesson tension bar.  I moved it to the second hole for more tension and the gap was larger.  Thess are the picture with more tension.  

[Dick White]

3 hours ago, Pres said:

"If your kiln is supplied with cones, the programmed cone number should match the cones provided, or you may use a cone of your own choice for the first firing. The example below is for a cone 04 firing, but if you use a cone other than 04, substitute that cone number in the programming." Immediately after this is the fast glaze fire menu in novice mode.

I guess I missed something somewhere in my reading about running a long glaze firing. I do not believe anything is damaged, but time will tell. As far as making adjustments I was just wondering, and I believe asking for opinions is better than trudging on without more knowledgeable help. This is a new world for me, but I am not without some skills.  I would think the manual would show a long firing for first firing instead of referring to a fast glaze immediately on the page for first firing????!!

 

best,

Pres 

I don't have a paper book copy of the manual here, but the download pdf version has a section titled "First Firing Instructions for L&L Kilns With A Dynatrol 700" immediately before the Bartlett Genesis chapter. That's where the slow bisque business is listed. Which, of course, yours isn't "with a Dynatrol," yours is with a Genesis. So that's poor editorial decision by L&L. And it's probably not the end of the world, but that's how we got where we are. Namely, all in it together.

[Dick White]

3 hours ago, Pres said:

For those of you looking at my question about adjustments, I would think this cone is pretty spot on, maybe a little hot. I had two included with the kiln, so one was at the bottom of the top sections, and one on the floor shelves. They both look almost exactly alike.

Well, actually, according to Orton, a self supporting cone is correctly fired when the tip is even with the top of the pyramid supporting base, not touching the cone pack/shelf as with regular cones. But the reality is there probably is only a few degrees/minutes difference between even with the top of the base and the shelf, so no harm. And as Bill pointed out, consistency with your glazes is what matters.

[neilestrick]

@Pres You definitely didn't do any harm with your first firing. I'll talk to L&L about making it more clear what should be done with the first firing. I think the confusion comes with the Genesis controller being added in as a separate booklet.

[neilestrick]

52 minutes ago, ECpot said:

The lid sat tighter with lesson tension bar.  I moved it to the second hole for more tension and the gap was larger.  Thess are the picture with more tension.  

They usually sit better with the lighter tension, use whichever works best. In that picture it looks like it's sitting pretty evenly side to side. Where is the gap? At the front?

[Bill Kielb]

2 hours ago, ECpot said:

The lid sat tighter with lesson tension bar.  I moved it to the second hole for more tension and the gap was larger.  Thess are the picture with more tension.

The bracket on the left looks loose and a bit lower than the bracket on the right. It might be the picture but Neil might have a comment like first level, next set lid flush, then tighten all screws ..... etc.... 

 

[neilestrick]

16 minutes ago, Bill Kielb said:

The bracket on the left looks loose and a bit lower than the bracket on the right. It might be the picture but Neil might have a comment like first level, next set lid flush, then tighten all screws ..... etc.... 

Definitely a possibility.

Might just need to start over with mounting the hinge. Pull the tension rod, loosen up the hinge, make sure the body bands are all tight and even, and start over. Have the springs sitting on the rod as mirror images. Does the lid sit flush all the way around when the hinge isn't assembled? Push the hinge up and make sure the spring rod is sitting in the bottom of the oval holes on both sides. Tighten everything up. Lid should still be flush and even at this point. Open it up all the way, insert the tension rod and close it. It should go back down and still sit evenly on the kiln. it may be off by a tiny bit side to side, but not so much that you can't just scootch it over a bit to get it to latch.