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Member Since 04 Oct 2011
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#92665 Cutting Kiln Shelves

Posted by neilestrick on 16 September 2015 - 09:28 AM

If they are black or dark grey, they are silicon carbide. Anything that is yellowish or cream, etc. can be cut with a masonry blade. I've cut them with a masonry blade on my circular saw with no problems.

#92617 Black Spots Falling From Lid Into Glaze

Posted by neilestrick on 15 September 2015 - 01:48 PM

I seems to me that what we have here is frustration on both sides. L&L is frustrated that they can't get photos, and Oldlady is frustrated that she didn't get a solution. IMO, I don't think anyone is to blame; it's just an unfortunate situation. This happens more often than I'd like to admit when it comes to technical support. I've been there myself, on both sides, and it's no fun for anyone.
Oldlady, I did not mean to say that you are being unreasonable, and I apologize if it sounded like that. This is simply a situation where we are not able to help you simply because we don't have the information needed to make a diagnosis. Sometimes, like in this situation, we have to actually see the kiln, or even see it in person. Without that we are just guessing, and wasting your time chasing solutions that won't help. That's not your fault, or lack of willingness, it's just the way it is.
Regarding the kiln itself, here's what I know:
The sad fact is that sheet metal costs are considerably higher than they were 30 years ago. Kiln companies use the best materials they can afford to use. This issue comes up regularly here on the forum, whether in regard to sheet metal or thermocouples or screws or whatever. If they built the 'perfect' kiln, no one would be able to afford it. If we had that kind of money we'd all have front loaders.
Kilns get all sorts of corrosion on them, and most of the time it's just on the surface and does no real harm to the metal. They only stay pretty for a short while. Screws will rust out to the point that they have no threads on them. There's a lot of water vapor and corrosive materials in the fumes that come out of the kiln.
Kilns require work over time. Unfortunately (but fortunately for repair guys like me), not everyone can work on their kiln, and a call to the local repair person is occasionally needed. Certain jobs are a real pain, others are simple. Yes, L&L elements can be changed with just a screwdriver and a wrench (I do it all the time), unless you've fired your elements to the point that they are a slumped over mess, in which case a pair of needle nose pliers will be helpful. But there are no element pins or crimp connections in an L&L, and that's their point- element pins and crimp connections are a pain to deal with, and make element changes take a lot longer than they should.
Every brand of kiln has it's benefits and faults. There is no perfect kiln, and no matter how well a kiln is built it will need repairs at some point, and there are some issues like corrosion that are unavoidable. Sometimes there are simple solutions, and sometimes not. I personally took more than two weeks to solve a very strange problem with a customer's kiln a few years ago. None of the other techs had ever seen the problem before, and L&L made a change to their kilns to prevent it from happening again. I do always do my best, but sometimes it's really difficult to find the solution.

#92581 Show Us Your Teapots

Posted by neilestrick on 14 September 2015 - 09:26 PM

So, I notice many of you use the pre-made handles for your teapots . . . for any particular reason?


I prefer the look and feel of an overhand handle, rather than a side handle, and overhand clay handles are a pain to make, take up a lot of space in the kiln, break easily during shipping, and make it difficult to clean out the pot. The cane handles fold over to the side for cleaning and shipping, and never break. I also like the look of the two different materials.


I've heard snobs who say that you should make your own cane handles, but I am of the opinion that I am a clay worker, not a cane handle maker. I'll leave that to the pros, just like many artists don't do their own framing or make their own brushes. I'm helping to support another craft.

#92541 Show Us Your Teapots

Posted by neilestrick on 14 September 2015 - 10:02 AM

Attached File  Teapot-Blue-Stripes.jpg   214.56KB   12 downloadsAttached File  Teapot-Boji-Dog-Breath.jpg   201.39KB   12 downloadsAttached File  Teapot-Green-Stripes.jpg   243.1KB   8 downloadsAttached File  Teapot-Cream-Stripes.jpg   170.44KB   8 downloads

#92365 Material Shopping List

Posted by neilestrick on 10 September 2015 - 02:46 PM

It's amazing what you can do with limited materials. If you've got the budget and space for everything, then great go for it. But if not, you can do an awful lot with:


1. Potash spar

2. Neph Sye.

3. Gillespie Borate or a high boron Frit like 3134

4. Dolomite

5. Whiting

6. EPK

7. Flint

8. Zinc Ox

9. Tin Ox

10. Red Iron Oxide

11. Cobalt Carb

12. Copper Carb

13. Rutile

14. Chrome Ox


These ingredients entirely make up 13 of the 15 glazes used in my studio, and could keep me busy with formulating tests for the rest of my life. These ingredients will give you almost any surface and color. With the addition of a small amount of Frits 3110 and 3124 I can mix the remaining glazes we use. I'd buy the first 7 in 50# bags, the rest as needed.


And get Alumina Hydrate for kiln wash.

#92357 Material Shopping List

Posted by neilestrick on 10 September 2015 - 12:42 PM

Cobalt Carb you could probably settle for 2#. You'll rarely use more than 0.5% at a time. No need to get oxide and carb IMO. Plus it's really expensive.


You can likely get away with plain old cheap Red Iron Oxide rather than Spanish, but many more pounds of either are needed. I buy it in 50# bags because it's used in half of my glazes. I don't keep Yellow at all.


Get 25# or more of Dolomite and Talc.


Lithium and Strontium may not be necessary unless you have specific recipes that call for them.


You'll need more than 1# Superpax/Zircopax. It takes about 10% to opacify a glaze. That's 2 pounds in a 5 gallon bucket.


More Tin Oxide. 4% to opacify a glaze, but up to 7% or more for a chrome-tin pink glaze.


Might not need both coppers. I only use carb in my studio and don't have any issues. You'll use up to 4-5%, so you might want to get 5#.


I do not keep Manganese or Barium in my studio (where I have classes and such) because of safety and liability issues. I can live without both just fine.


Spodumene and Redart are not needed unless you have specific recipes that call for them.


You only need one soda spar if you can reformulate glazes well. I've got a bag of F4 that's been sitting for 10 years. I just use Neph Sye.

#92281 Glaze Mixing Question - Small Batch Vs Large Batch Differences, Because Of Mi...

Posted by neilestrick on 08 September 2015 - 09:11 PM

The stick blender is a high-shear type mixer. It runs very fast, with very sharp blades that are intended to cut and shear particles into smaller sizes. The drill mixer is just a mixer. It moves stuff around enough that things that are clumped up tend to fall apart, but it runs much slower than the blender, and does not have any shearing action. If you're getting speckling, you need to use a smaller screen.


Commercial glaze suppliers have larger volume high shear mixers than can reduce particle size in such a way that they don't have to screen the glazes.

#92243 Duncan Kiln Not Reaching Cone 5...stumped?

Posted by neilestrick on 08 September 2015 - 12:44 PM

How hot can you actually get too? Its possible if your getting to like 2100 you can easily get cone 6 out of that by holding the kiln.


You'd be soaking for 3-4 cones, which is a lot, and some glazes will not respond to that. Plus you'll be putting a lot of stress on the elements. I wouldn't rely on it as a long term solution. Call Paragon, who handles Duncan kilns now, and see if that elements resistance is correct. According to the manual I saw, it should be pulling 40 amps.

#91864 Help! Help! Haaaalp! (Kiln)

Posted by neilestrick on 02 September 2015 - 08:59 AM

You cannot mess around with amps! It doesn't matter how hot you go. When you turn it on high it's going to pull 47 amps whether the kiln is at 85 degrees or 2300 degrees.

#91800 Liability Shift On Cc Coming Oct 1, 2015

Posted by neilestrick on 01 September 2015 - 11:20 AM

The difference is that the chip in the card makes is harder to use stolen information than a magnetic stripe:


Unlike magnetic-stripe cards, every time an EMV card is used for payment, the card chip creates a unique transaction code that cannot be used again.

If a hacker stole the chip information from one specific point of sale, typical card duplication would never work because the stolen transaction number created in that instance wouldn't be usable again and the card would just get denied.

#91706 Fritware?

Posted by neilestrick on 30 August 2015 - 09:48 AM

Gillespie Borate.. replacing Gerstley Borate?


Yes. It's a consistent blend of the minerals found in Gerstley, made by Hammil and Gillespie. I have found that it tends to be a bit stronger than Gerstley, so  bit less can be used. You could also test Frit 3134 for bringing down the temp.

#91652 Weird Liquefied Slip ....

Posted by neilestrick on 29 August 2015 - 08:54 AM

The only good cure for over flocculating or de-flocculating is to increase the amount of material and water, so as to dilute the effect.


I had an algebra teacher named Mr. Disco.

#91651 Fritware?

Posted by neilestrick on 29 August 2015 - 08:51 AM

All my feldspars, kaolin, silica, whiting, dolomite cost 0.70~ per kg and the cheapest frits I can find cost 4.00 per kg minimum for what they call 'standard borax frit'


The only ferro frit I can find is 3110 at 6.14 per kg.


I didn't think about element life too much and probably don't have enough experience with kilns to make a good opinion :D I just feel its slightly 6 or two threes. Reducing cost in some places increases it in others. No AC needed in the UK, especially up in Newcastle.


Bummer on the frit prices! Are they all imported?


Here's an example of one of my cone 6 glazes with very little boron (frit). It's a fake ash glaze of sorts, but doesn't run into rivulets. It goes on very nice, and will have matte and semi-glossy areas depending on thickness and how it's cooled.


S-4 Blue

Dolomite  1.87

Custer Feldspar  48.56

Whiting  28.01

EPK  12.29

Flint  6.35

Gillespie Borate  2.91

Rutile  4.50

Cobalt Carb  0.75

Red Iron Oxide  2.00

#91588 Underglaze Question

Posted by neilestrick on 28 August 2015 - 08:47 AM

Underglazes have a lot of colorant in them. They are very saturated colors, so even if they are fired high enough to gloss over they could still leach. Glossiness does not indicate food safety.

#91531 Proper Reduction Firing Schedule

Posted by neilestrick on 27 August 2015 - 02:44 PM

A reduction soak is not necessary at the end of the firing. If you haven't achieved reduction by then it's too late. For some glazes, however, it helps to do an oxidation soak at the end. I used to do it for my copper reds, as it cleared any muddiness out of the edges where the glaze breaks to white.


Get up to body reduction temps- cone 012 to 08- as quickly as you can while not cracking any pots and maintaining evenness. No sense wasting gas with a really slow climb if everything has been bisqued. Put the kiln into reduction at cone 012-08, and stall out the climb. Hold temperature with the reduction for 45 minutes. If you're trying to carbon trap a shino glaze, then make this a heavy smoky reduction. Then put it into a neutral atmosphere and let it climb to cone 10. Stalling it out in reduction will ensure that you get good reduction throughout the kiln, and climbing in a neutral atmosphere will give you an efficient use of gas.