ITC in Electric Kilns

[OffCenter]

Is spraying the inside (obviously including the elements) of an electric kiln with ITC a good idea? Do you have any experience with this, neilestrick?

 

Jim

[Mark C.]

I did this once long ago.

Mark

[neilestrick]

I have never used ITC in a kiln. Personally, I haven't seen the numbers to justify the cost. All I ever hear is it makes it 'better', but I don't know how much better. Technically, 5% longer element life is better, but that's not enough to make me want to use it. From a customer's standpoint, the cost of the material with the added cost of my labor would make it ridiculously expensive. I believe Axner is the only one who sells new kilns with the coating already applied. If it was truly a miracle product, I would expect others to use it, too. I think Axner mostly uses it as a marketing gimmick.

 

L&L puts a brick hardener on their kilns. I don't know what the formula is, but it definitely helps to some degree with brick life.

 

ITC won't damage your kiln, so if you want to try it, go for it. But in the time it would take me to do the application and reapply it in the future, I can make enough pots to more than cover the savings I might get out of it. Saving money on firings doesn't mean anything if I'm losing time in the studio.

 

Say I buy a pint for $125 and apply it to my kiln and I get a 10% savings in firing costs. That's about $1 per firing. So if I fire 3 times a week during the year I've saved $150. Minus the cost of the material I'm up $25. But if I spent two hours during the year doing the initial application and touching it up, that's enough time at the wheel to make several hundred dollars (maybe even a thousand) worth of pots. That's no savings.

[Guest JBaymore]

I have never used ITC in a kiln. Personally, I haven't seen the numbers to justify the cost. All I ever hear is it makes it 'better', but I don't know how much better. Technically, 5% longer element life is better, but that's not enough to make me want to use it. From a customer's standpoint, the cost of the material with the added cost of my labor would make it ridiculously expensive. I believe Axner is the only one who sells new kilns with the coating already applied. If it was truly a miracle product, I would expect others to use it, too. I think Axner mostly uses it as a marketing gimmick.

 

L&L puts a brick hardener on their kilns. I don't know what the formula is, but it definitely helps to some degree with brick life.

 

ITC won't damage your kiln, so if you want to try it, go for it. But in the time it would take me to do the application and reapply it in the future, I can make enough pots to more than cover the savings I might get out of it. Saving money on firings doesn't mean anything if I'm losing time in the studio.

 

Say I buy a pint for $125 and apply it to my kiln and I get a 10% savings in firing costs. That's about $1 per firing. So if I fire 3 times a week during the year I've saved $150. Minus the cost of the material I'm up $25. But if I spent two hours during the year doing the initial application and touching it up, that's enough time at the wheel to make several hundred dollars (maybe even a thousand) worth of pots. That's no savings.

 

 

Neil,

 

It is nice to see someone who "gets it" when it comes to business and the most costly and ireplaceable thing in the studio; your time.

 

best,

 

................john

[neilestrick]

 

Neil,

 

It is nice to see someone who "gets it" when it comes to business and the most costly and ireplaceable thing in the studio; your time.

 

best,

 

................john

 

 

Thanks. While making pots is not where I spend the majority of my time, it is the area where I am ALWAYS short on time. So unless an activity is absolutely necessary to keeping my business afloat, it is probably a waste of my time and not going to come out more cost effective than finally sitting down at the wheel and making pots. Spraying the inside of my perfectly good L&L kilns with ITC falls into that category. Plus that $125 could go toward three kiln shelves, which I actually NEED.

 

Even if you break down the cost over many years, I still don't see the ITC being worth it. It must be reapplied every time you replace the elements. At some point it will be so layered up in your element grooves it will be a mess. I often see kilns, especially L&L, that have been fired regularly for 30 years and the bricks still look great. I can't imagine that 30 years of ITC being applied to the elements won't eventually gunk up the grooves. How will that extend the life of my bricks? $125 every year or two to coat my new elements? Not worth it.

 

 

My students often fall prey to the marketing of pottery products. Get a Giffin Grip instead of learning how to tap center. Get a handle making tool instead of learning how to pull handles. Get this, get that and your pots will be better without trying! There are few, if any, tools that take the place of skill. There are few tools that will save you enough time to be worth their cost. Focus on building skills and becoming competent at all aspects of making pots. Spend your time where it counts.

[Guest JBaymore]

My students often fall prey to the marketing of pottery products. Get a Giffin Grip instead of learning how to tap center. Get a handle making tool instead of learning how to pull handles. Get this, get that and your pots will be better without trying! There are few, if any, tools that take the place of skill. There are few tools that will save you enough time to be worth their cost. Focus on building skills and becoming competent at all aspects of making pots. Spend your time where it counts.

 

 

 

 

AMEN!!!!!!

best,

 

..................john

[yedrow]

My students often fall prey to the marketing of pottery products. Get a Giffin Grip instead of learning how to tap center. Get a handle making tool instead of learning how to pull handles. Get this, get that and your pots will be better without trying! There are few, if any, tools that take the place of skill. There are few tools that will save you enough time to be worth their cost. Focus on building skills and becoming competent at all aspects of making pots. Spend your time where it counts.

 

 

 

 

AMEN!!!!!!

best,

 

..................john

 

 

May I second that Amen! And thanks for the excellent insight folks. I think I've made up my mind about ITC. I still would like to know how it works, but Neils perspective on it suggests that it doesn't do the astounding things I've heard of it doing. I won't be spending money on it for my own stuff.

[OffCenter]

My students often fall prey to the marketing of pottery products. Get a Giffin Grip instead of learning how to tap center. Get a handle making tool instead of learning how to pull handles. Get this, get that and your pots will be better without trying! There are few, if any, tools that take the place of skill. There are few tools that will save you enough time to be worth their cost. Focus on building skills and becoming competent at all aspects of making pots. Spend your time where it counts.

 

 

 

 

AMEN!!!!!!

best,

 

..................john

 

 

May I second that Amen! And thanks for the excellent insight folks. I think I've made up my mind about ITC. I still would like to know how it works, but Neils perspective on it suggests that it doesn't do the astounding things I've heard of it doing. I won't be spending money on it for my own stuff.

 

 

Hold on, Yedrow, you may want to look into it a little more before making up your mind. Probably not a good idea to let one person who hasn't used a product make up your mind about a product. I know ITC is great stuff for many atmospheric kiln applications and some people make extraordinary claims for using it in electric kilns (for example, just for starters, see: http://www.axner.com...has-to-say.aspx) (Yes, I know it's an ad but other places say much the same but not as condensed.), so I wanted to see what people on this forum (especially Neil since he seems to be especially knowledgeable about electric kilns) think about using it on electric kilns (looking for potential problems like flaking or damaging the elements, etc.).

 

Jim

[OffCenter]

Neil, thanks for the response even if it did turn into more of a time management lecture (that is of no interest to me) than a factual report on a product.

 

Mark, why did you use it on an electric kiln that isn't fired high instead of on one of your other kilns? Expense? Labor?

 

Jim

[yedrow]

Jim,

 

My main problems are the price and science of it. The price I can live with is one thing, but it seems that there should be some information that gives an informed explanation of how this stuff works. I believe everyone who says it works great for them. But, I have a spend-rule that says that if I can't find out how a thing works then I shouldn't buy it. If it is reflecting heat away it seems a small thing just to tell people. Not doing so makes the product look, well, like Bernie Madhoff stock. It may be the best kiln maintenance product on earth, but I can't tell without having some idea of the mechanics behind it, and $150 is a lot of money to me (potter poor). I'm especially bothered by a ceramic-metal interaction when it is used on kiln elements. Applying such coatings in a lab, under vacuum say, makes sense. But just dipping them seems to suggest "marvelous" qualities.

 

Edit: Oh, and another thing that causes me concern is the difference in coefficients of expansion between the various substrates; ITF and, IFB, nickel-chromium (guessing on elements), hard brick, mortar, etc. I'm guessing this is the reason for the thin coating, but that then raises a question about the best application verses the most versatile application.

[Guest JBaymore]

Jim,

 

I have used the stuff on client's kilns and I also use it VERY limitedly for certain things on my noborigama.

 

On client's kilns (all fuel-fired) it is mainly employed for protecting the IFB from sodium compounds. Mainly soda not salt. It appears to retard the detrerioration but does not stop it completely. Any potential fuel savings and heat energy distribution improvements are totally incidental to this original intent.

 

First step for this application is in selecting the one single IFB that tends to resist soda better than the others; Thermal Ceramics 25s. Then prepping the surface correctly by literally spraying it down with water and scrubbing off the loose IFB particles with a stiff brush. Then spraying on a THIN coating of ITC while stirring/shaking the resivor of material constantly (it settles FAST). It does not adhere to used IFB as well... and tends to flake off.

 

As I said in the other ITC related thread, I've tested it on one small electric kiln for energy usage changes. Came back at about a 10-12% decrease in kilowatt hours used (YMMV). Unless you are doing reduction in an electric kiln and want to extend elelment life a bit with the ITC 213 on them, I can't see the significant payback in using it there.

 

On the noborigama I mainly use it for coating the assembled IFB round stoke hole plugs to limit abrasion of the plugs as they are taken in and out (it does do this better than a regular fireclay-type mortar coating) and (potentially) increase the reflectivity of the "weak link in the insulation chain" in the wall section (plugs are thin compared to the walls).

 

Attached is an image of a Bailey gas kiln that was ITC 100 HT-ed after I had relined it with better grades of brick than is originally used (different grades in different locations). The old lining was totally shot. The ITC used here was because it was being used for high temperature saggar firing quite regularly, and one of the constituents of the saggar loads was significant amounts of sodium compounds like soda ash, salt, and seawater impregnated sea shells. It definately appears to protect the IFB in that case over the non-protected brick .... but again this is not a "controlled test" using the scientific method...... just more apochrophal evaluation.

 

In a little while I'll try to also attach an image of a soda kiln I designed with the ITC sprayed onto it.

 

best,

 

.......................john

 

 

 

[Guest JBaymore]

I'm especially bothered by a ceramic-metal interaction when it is used on kiln elements. Applying such coatings in a lab, under vacuum say, makes sense. But just dipping them seems to suggest "marvelous" qualities.

 

Yedrow,

 

Yup........ the weak link here is the single place that the coating is non-contiguous in the application. If the ceramic shell is not fully intact, then the place the coating is not is the place that the gases from the kiln will still reach the underlying metal ....and it will still fail right there.

 

And ITC does not get applied to hard brick... it does not bond.

 

best,

 

.......................john

[Mark C.]

Neil, thanks for the response even if it did turn into more of a time management lecture (that is of no interest to me) than a factual report on a product.

 

Mark, why did you use it on an electric kiln that isn't fired high instead of on one of your other kilns? Expense? Labor?

 

Jim

 

 

At one time the hype was to spray it on everything-toast-eggs muffins even electrics

I just wanted the bricks to have a tougher surface on them especially the top part where abrasion happens

The stuff was cheaper way back then so I sprayed it on the top and while i was in there (spray setup was handy) I just coated the whole chamber.

It did put a tough surface on the bricks-within 10 years I got bought out another potter and got a larger electric she had and moved that into my main use electric so the ITC coated electric kiln now is a table.

Mark

[neilestrick]

I stand by what I said, but I am in no way the final word on this subject. I'm just saying that until I see actual numbers it's not worth it for me. All of the statements on Axner's page are vague- "Extends the life of your elements". How much? 1%? 25%? Give me numbers! Adjusting your firing schedule can extend the life of your elements, too.

 

I am not doubting that it does all the things it says it does. But I've seen home-made coatings that do the same thing. It's not that difficult to make a coating that will resist salt and harden the face of soft brick. I just haven't seen any numbers to justify the cost and labor in an electric kiln. And I'm still concerned about it filling up the element grooves over the years. And Like John said, anywhere an element is not coated, it becomes a weak point in the system. It seems to me that it will just become more flakes of crud to vacuum out of the element grooves.

 

I'll try to find some time this week to Google about and see if anyone has any numbers on element life with ITC.

[OffCenter]

Wow! Thanks everyone. You've all been a great help. Getting this kind of help is what make this forum so worthwhile.

 

Jim

[neilestrick]

So I just looked through a couple dozen pages of Google results regarding ITC coatings, and here's what I have found:

 

- Most of the data collected concerns using ITC in gas kilns, specifically in salt, soda and wood kilns, to protect the bricks from the corrosive vapors. It works great for this. Can you make your own coating that will also work great, and for a lot less money? Yes.

 

- ITC increases the efficiency of the kiln by creating a surface that reflects more heat back into the kiln, rather than being absorbed by the bricks. Some gas kiln people report fuel savings of up to 35%. I only found a couple of reports on electric kilns, and they reported a savings of about 10%. That means about $1 per firing, which was the number I used in my figures earlier to decide that it wasn't worth the money. I could not find anything that does a direct comparison between ITC and home-made kiln washes.

 

- ITC is great for fiber kilns. Makes a lot of sense to me. Fiber is very fragile, and hardening the surface with ITC will increase its life, as well as lock up the fibers so they aren't inhaled. It also helps hold the heat in better. Fiber kilns cool notoriously fast.

 

- All of the claims about increasing element life that I found are very vague. They range from 'longer life' to 'many times longer life'.

 

- Proper application of ITC seems to be the biggest problem. I found as many complaints as positive comments. The experts say the number one mistake is applying it too thickly. To apply it to an electric kiln they recommend first taking the elements out, then spraying the inside of the kiln with a watered down solution using a sandblasting sprayer. The elements should be dipped in to the watery solution then hung to dry before re-installing them. Apparently the coating will not flake off and remains flexible. They do not recommend applying ITC to the bricks or elements with a brush, as it results in too-thick, globby areas that will flake off.

 

- The number one claim by the experts is that the ITC coating protects the elements from the corrosive vapors in the kiln, even in a reduction atmosphere.

 

- Skutt does not recommend using ITC in their kiln. Euclid's elements found that there was no real element life advantage over a well ventilated kiln.

 

It seems to me that if the corrosive nature of kiln vapors was a major culprit in element degradation, then bisque firings would do more damage to an element than glaze firings, since way more stuff burns out in a bisque than in a glaze firing. Yet it is well known that elements that only ever fire at low fire temps last many times longer than elements fired to cone 6. In speaking with Steve Lewicki at L&L a few months ago, he said the main two contributors to element degradation are temperature and cycling (turning on and off). He said the folks who make element wire didn't have any hard data on how the two compared, though. In my own not-so-scientific study, temperature seemed to play a greater role than cycling.

 

At this point the only thing I can say with fair certainty is that you may gain a 10% increase in energy savings by putting ITC in your electric kiln. I'll keep looking for some more definitive data on element life.

[Marcia Selsor]

Neil,

I think you get worse vapors in glaze firings that can harm elements with those fumes coming from the glaze chemicals.

Andto give specific numbers for ITC benefits is nearly impossible because as you say it depends on the way you fire, the temperature, down firing, etc.

I have used ITC for about fifteen years or more. I find it beneficial. I got it a long time ago. Feriz send me fiber squares to use with ITC,

I have used it on car kiln doors and hinged doors for high fire using two layers of 8 lb fiber and insblok boards.

All I can say is it seems to me to be beneficial by compariison with 44 years of firing experience. That is all I can contribute.

Marcia

[neilestrick]

Neil,

I think you get worse vapors in glaze firings that can harm elements with those fumes coming from the glaze chemicals.

Andto give specific numbers for ITC benefits is nearly impossible because as you say it depends on the way you fire, the temperature, down firing, etc.

I have used ITC for about fifteen years or more. I find it beneficial. I got it a long time ago. Feriz send me fiber squares to use with ITC,

I have used it on car kiln doors and hinged doors for high fire using two layers of 8 lb fiber and insblok boards.

All I can say is it seems to me to be beneficial by compariison with 44 years of firing experience. That is all I can contribute.

Marcia

 

 

Using it with fiber boards or blanket seems to be one of the most beneficial applications for ITC. I think there are some very strong arguments for using it in fuel fired kilns. Most people report faster firings when using it. Seems the jury is still out on electric kilns, though.

[bciskepottery]

Nils Lou has a discussion of ITC and pictures of how to apply, etc. in his book The Art of Firing.

[yedrow]

just more apochrophal evaluation.

 

 

I like the way you talk mang!

 

There is a lot of great information here. I for one appreciate it.

 

Joel.

[Riorose]

I disagree about the Giffin grip. We use it for too many things to mention. It was pricy but in our opinion more than worth it. and this is coming from a woman who doesnt like to pay for anything that I can make especially in view of the fact that here in Portugal we can't get all the fancy stuff you can easily find in the USA.

[OffCenter]

Neil, I goggled a lot of the same info before my original post. Thanks for taking the time and summarizing. I had already decided that as expensive as it is, ITC is worth the money for atmospheric kilns. Not so sure about electric kilns. One use I have planned for it, when I have the time and money, is a salt kiln built out of panels made of ceramic board (1 inch, 2600 degrees for hotface) backed by several inches of fiber, then ceramic board (1 inch, 1800 degrees). The hotface ceramic board would be coated with ITC.

 

Jim

[Guest JBaymore]

One use I have planned for it, when I have the time and money, is a salt kiln built out of panels made of ceramic board (1 inch, 2600 degrees for hotface) backed by several inches of fiber, then ceramic board (1 inch, 1800 degrees). The hotface ceramic board would be coated with ITC.

 

Jim,

 

That will slow the erosion down... not stop it. Good choice to use board over blanket.

 

best,

 

.......john

[OffCenter]

One use I have planned for it, when I have the time and money, is a salt kiln built out of panels made of ceramic board (1 inch, 2600 degrees for hotface) backed by several inches of fiber, then ceramic board (1 inch, 1800 degrees). The hotface ceramic board would be coated with ITC.

 

Jim,

 

That will slow the erosion down... not stop it. Good choice to use board over blanket.

 

best,

 

.......john

 

 

Glad you commented, John. Now, that I hooked you with that, do you think thicker ceramic board would work for a floor? I've used kaowool years ago when I built kilns in Colorado, but have never used board. It comes it several thicknesses. I'm thinking same kind of panel mentioned above only thicker for floor directly over cinder blocks.

 

Thanks,

Jim

[Guest JBaymore]

One use I have planned for it, when I have the time and money, is a salt kiln built out of panels made of ceramic board (1 inch, 2600 degrees for hotface) backed by several inches of fiber, then ceramic board (1 inch, 1800 degrees). The hotface ceramic board would be coated with ITC.

 

Jim,

 

That will slow the erosion down... not stop it. Good choice to use board over blanket.

 

best,

 

.......john

 

 

Glad you commented, John. Now, that I hooked you with that, do you think thicker ceramic board would work for a floor? I've used kaowool years ago when I built kilns in Colorado, but have never used board. It comes it several thicknesses. I'm thinking same kind of panel mentioned above only thicker for floor directly over cinder blocks.

 

Thanks,

Jim

 

 

Jim,

 

Sucking me in on a free kiln design consult bit eh?

 

When doing kilns for clients I never use anything except a hard dense refractory for kiln floors. If you were amazingly careful........ it might be OK. All of the "crap" that ends up happening eventually ends up on the floor . If the kiln is large, you will be stepping or at the least kneeling on this surface. Over time, this really wears on it. (If you use a protective wood "loading board" that might help a bit.)

 

One tactic to use without increasing the thermal mass too much is to use hard thin splits for the floor surface. Another tactic is to use good kiln shelves cut to the necessary size to "laminate" onto the working floor surface.

 

If you use the board for the floor, remember that you are still going to want to insert a hard refractory weight bearing "pad" below where the load bearing stacking of shelf posts will go. The fiber board will break down over time there for SURE. But if you tie yourself to only one configureation with this loaction on the build... you are then "stuck".

 

Also I don't know what you are meaning about the thicknesses....... but don't overestimate fiber's insluation value when you plan on the wall / roof/ floor thincknesses. Fiber's big advantage is it's low thermal mass.... not its super insulating value.

 

best,

 

.......................john