Favorite store bought kiln wash?

[not a bot]

Hi,

 I searched for info or reviews about store bought Kiln Wash in anticipation of a new LnL kiln being delivered in a couple months. We have some CoreLite shelves to protect as well.

 I found some info suggesting you can make your own wash from glaze making supplies, but we don't have any glaze making supplies.

 I also found some comments about store bought washes becoming "flaky".

 I could not find any discussions comparing and contrasting one or the other pre made products.

 This article was helpful, but it did not point me to a specific product we could locate and purchase easily.

 https://ceramicartsnetwork.org/daily/article/The-Many-Layers-of-Kiln-Wash-How-to-Find-the-Best-Kiln-Wash-for-Your-Firing-Temperature-and-Methods

 Any suggestions?

 Thank you.

 

[Bill Kielb]

Lees kiln wash is like iron, won’t flake and is fairly expensive but it does work well. Can be purchased many places, here is one https://www.axner.com/kiln-wash-lees-by-axner.aspx

Sue Mcleod has a nice recipe that is simple to make  https://suemcleodceramics.com/how-to-make-a-good-kiln-wash-to-protect-your-kiln-shelves/

There are others here as well, maybe search kiln wash on the forum.

Flaky is a big complaint, Lees will not flake and the various good recipes you will find generally the feature folks like, not too flaky, can be touched up relatively easily and can be removed with reasonable pressure / scraping.

[not a bot]

Hi,

 Thanks Bill. I just went and looked at the Lee's by Axner and the price of the product seemed fine. I was ready to place an order, but the shipping and handling for a gallon jug was $54.

 I just UPS ground shipped a truck's driveshaft (40lbs in a big box) across the country for half that cost.

However, the mention of Lee's made me search and unearth some discussions that occured in 2009 claiming that the recipe was shared by "Lee" to other producers, which made me wonder if any other 2022 producers make a product that incorporates all the ingredients that makes Lee's noteworthy. 

Thank you.

[Bill Kielb]

7 minutes ago, not a bot said:

which made me wonder if any other 2022 producers make a product that incorporates all the ingredients that makes Lee's noteworthy. 

To my knowledge it’s been unique and lots of folks always wanted it. My last visit to Axner, (a couple years ago) the manager said the recipe was under lock and key.

Edited August 3, 2022 by Bill Kielb

[oldlady]

the discussion on kiln wash is neverending.   it ended for me when this recipe was given by one of the most experienced potters here.  i applied it then, years ago, and have not had any flaking or other problems.  it just stays there, quietly doing its job.   i do not seem to spill glaze on shelves so i do not have to clean them often.   years ago.  i mostly use it on new shelves.

one of the ingredients is calcined EPK.   to calcine the EPK, just fire a bowl full, i think to just bisque temperature.  once mixed with water, the wash stays wet if in a tight container.  if it dries out, just add some water to a consistency that allows application by small roller.  you can buy the two ingredients at any supply store if there are any in your area of the USA

 

recipe for kiln wash

50% alumina hydrate

25%  Edgar Plastic Kaolin   EPK

25% calcined Edgar Plastic Kaolin  EPK

 

 

 

[Min]

Thread on kiln wash here. https://community.ceramicartsdaily.org/topic/20981-frit-substitution-chart-orton-cone-charts-kiln-wash-recipes/

[not a bot]

That thread seems to share details about making your own kiln wash.

We do not foresee making our own glazes in the near future so did not anticipate having glaze making materials on hand which could also be used to make our own kiln wash.

Is Lee's the only store bought kiln wash that uses the Zircon mentioned in that thread?

Thank you!

 

 

Edited August 3, 2022 by not a bot

[Jeff Longtin]

Continental Clay makes an "Alumina based" kiln wash that is terrific. (They also make a "silica-based" kiln wash which I don't use.)

As the recipe OldLady  mentions is fairly simple, and universal, I presume the CC product duplicates it.

[Min]

@not a bot, I don't know of any other commercially mixed kiln wash containing zirconium. I get that you are not planning on stocking glaze materials so you don't want to purchase materials for kiln wash. If you are dead set on using a zirconium wash you might have to compromise between paying the shipping from Axner or mixing your own.

There is a recipe here from Tony Hansen. I haven't tried it so can't comment on how it works. Pricing it out from what it would cost from my local supplier it would be about $12 for the zircopax plus $12 for the epk (smallest size bag my supplier has, it would only cost pennies for the amount you would use if you can get a smaller amount) $9- for a pint of gum solution and around $10- for the calcium chloride (from online, used as an ice melter in the winter), would only use a tiny portion of the bag. This recipe makes about a pint and is supposed to cover about 18 ft2. So doing the back of the napkin math, approx $44 to make the first pint then going forward it would be the cost of the zircopax  since you would have leftovers of everything else which would be around $14 a pint at the most.

Edited August 3, 2022 by Min

[not a bot]

Thank you for the detailed information.

Thank you!

 

[neilestrick]

The Hansen recipe would suspend better if half the EPK, or even 5%, was not calcined. At that small amount it shouldn't change the shrinkage enough to cause cracking/flaking.

[Min]

1 hour ago, neilestrick said:

The Hansen recipe would suspend better if half the EPK, or even 5%, was not calcined. At that small amount it shouldn't change the shrinkage enough to cause cracking/flaking.

Pretty sure some MAGMA would keep it suspended well too.

[not a bot]

Hi,

 I had asked about the Zircon because the Frit Substitution Chart + Orton Cone Charts + Kiln Wash Recipes thread seemed to suggest that it was the magic ingredient.

 I started this thread naively thinking there would be an established answer for ceramic kilns and that the products sold "ready made" were based on a 19th century body of knowledge.

 I did not realize that this was such a popular topic of discussion and that there was such a variety of recipes still contending for consideration.

 

Edited August 3, 2022 by not a bot

[Bill Kielb]

3 hours ago, not a bot said:

 I did not realize that this was such a popular topic of discussion and that there was such a variety of recipes still contending for consideration.

If you look at several of the successful recipes you will find a great deal of similarity with calcining a portion of the clay to reduce shrinkage. I think Sue McLeod has nearly the same recipe as above but does include some silica and ……. Mixes it thin,  then flocculates it to a desired thickness. They all seem to work, are super cheap and easy to prepare and many find them reliable.

Folks have “speculated” that Lees is zircon based. I am not sure anyone knows it’s actual composition and while true it is very hardy, it’s also hard to remove comparatively in my experience with it. Since much of clay is geologic (Extremely old materials) old knowledge probably is still pertinent and effective.

Specialized refractory coatings have however improved over the last decade or two though.

Edited August 4, 2022 by Bill Kielb

[PeterH]

John Britt's summary of kiln wash recipes, with some thoughtful explanations.
The Many Layers of Kiln Wash: How to Find the Best Kiln Wash for Your Firing Temperature and Methods
https://tinyurl.com/3695jpf2

... and a deflocculated variant of one of them
Self-Leveling Kiln Wash https://jeffcampana.com/self-leveling-kiln-wash/
and https://glazy.org/recipes/42065

PS From the comments section of the self-leveling kiln wash paper

John Britt says: October 11, 2010 at 11:21 am
Nice Jeff, I believe that is called Lee’s Incredible Kiln Wash” $25.00 a gallon on Etsy,

... although contrast with  @Bill Kielb's earlier comment
Folks have “speculated” that Lees is zircon based. I am not sure anyone knows it’s actual composition

Edited August 4, 2022 by PeterH
extended ps

[not a bot]

Hi,

 I just read this info which I found with a Google search: https://cone6pots.ning.com/photo/kiln-wash

Just as some of the posts here have done, it described and compared some of the cost of materials. I am starting to appreciate why the attractively priced ready made products do not exemplify the best in class performance.

I can imagine that by the time a consumer is educated enough to understand how material choice relates to cost of raw materials they are comfortable purchasing the raw materials and mixing the recipe them self.

I may have to learn how to shop for these materials sooner than I would have guessed.    :-)

Thank you!

Quote

 

 

Edited August 4, 2022 by not a bot

[neilestrick]

2 hours ago, not a bot said:

Just as some of the posts here have done, it described and compared some of the cost of materials.

The good news is that if you make or buy a good quality kiln wash, it will last for quite a long time.

[Min]

14 hours ago, Bill Kielb said:

Folks have “speculated” that Lees is zircon based. I am not sure anyone knows it’s actual composition and while true it is very hardy, it’s also hard to remove comparatively in my experience with it.

I emailed Axner and asked for the SDS as I couldn't locate it on their site. Link they sent me is here , which, to me anyways, just makes things more confusing. SDS they sent me lists only silica and alumina and is for FR503 aka Axner Kiln Wash. I then questioned if the SDS was the same for Lee's Kiln Wash because I was under the assumption it contained some form of zircon. Received this reply back: 

"We haven't changed the formula.

The names are interchangeable since we bought Lee's recipe but we still make as he intended."

Curiouser and curiouser because being able to coat both top and bottom of the shelves it does sound like more than an alumina oxide + silica wash. 

For what it's worth when I was back in school the tech used a zircopax wash on the kiln shelves for the gas kiln. Both sides were washed, shelves fired with no flaking or bits falling onto pots. He would re-coat the shelves without removing the previous coats, shelves were really quite thick with all the years of built up layers.

Edited August 4, 2022 by Min

[neilestrick]

In grad school we used zircon flour and EPK to make wadding for the salt kiln. Worked great. Our tech made a wash for the walls of a little test salt kiln he made, zircon flour, kaolin, colloidal silica, and other stuff. If I remember correctly it worked very well and didn't flake.

I use the Alumina/EPK mix on my shelves, and some have quite a thick layer on them, like 1/16" or more. I keep telling myself I'm going to grind them down and start fresh, but I haven't found a good reason to do all that work since they function just fine as is.

[Bill Kielb]

2 hours ago, neilestrick said:

keep telling myself I'm going to grind them down and start fresh, but I haven't found a good reason to do all that work since they function just fine as is.

I belt sanded a bunch absolutely clean then started using Lees. Lots of dusty work, bonded nitride from now on!

Edited August 4, 2022 by Bill Kielb

[neilestrick]

40 minutes ago, Bill Kielb said:

I belt sanded a bunch absolutely clean then started using Lees. Lots of dusty work, bonded nitride from now on!

I've thought about using the belt sander. Good to know it works. I might wait until I've got one that's getting near the end of its life, though, as I can't imagine it will live much longer after sanding kiln wash.

[Bill Kielb]

16 hours ago, neilestrick said:

I've thought about using the belt sander. Good to know it works. I might wait until I've got one that's getting near the end of its life, though, as I can't imagine it will live much longer after sanding kiln wash.

Lots of very course belts (They clog rather quickly) and lots of paint booth exhaust ………… and ear protection for sure. Belt sander made it ok, kind of normally used in a dusty environment anyway.

[not a bot]

As I slowly absorb information about Kiln wash etc. I have been trying to make sense of all the different ideas I have encountered.

I stumbled upon a old circa 2009 post by John Britt: http://johnbrittpottery.blogspot.com/2009/10/kiln-wash-recipes.html where 9 different recipes are presented. It seems likely that one recipe would be more practical than the others, so I have continued to read what ever I can find. I understand that different characteristics will be more or less important depending on your personal needs, but I can't help thinking that the physics behind the scenes is nearly universal.

Reading through the comments posted on various recipe webpages it seems as if substituting Zircon for the Alumina Hydrate can result in a very durable coating, but some people feel that can be a disadvantage, especially if and when maintenance requires removal of the material for a fresh new coating. Speaking for myself this has reduced the appeal of using a zircon product. This is my current inference. In other words, I may be wrong and have not realized it yet.

On paper, and in my imagination, the John Britt recipe that includes Feldspar seems to strike a balance between tenacity and practical work ability. 

It seems noteworthy that the suggestion for using a bit of Feldspar as a flux was sourced from an unnamed engineer who is professionally dedicated to producing ceramic products on an industrial scale at a enterprise founded in 1871. When I previously mentioned a "19th century body of knowledge" this was the sort of trickle down information I had anticipated to have been long ago adopted by ceramic enthusiasts. I think I knew that a lot of ceramicists are fascinated with alchemy, but I guess I expected the chemistry of kiln wash to be done and dusted.

It took me a while to get used to the idea, but I have learned that it is not difficult to locate and purchase most of the raw materials. It seems easy enough to purchase the Alumina Hydrate, the EPK, and the GloMax at a ceramics supply store.

I am having trouble identifying the Feldspar. The original John Britt recipe calls for G-200 feldspar. I have seen a few recipes updated with other specific Feldspar products, however I am having trouble correlating any of the descriptions to product I can find and buy at a ceramics supply store. I found some Glazy web pages with feldspar product analysis figures, and a few of the variants corresponded some of the products I found at the Laguna Clay materials catalog.

Can you help me figure out what Feldspar would be suitable and where to get it?

Any other comments, suggestions will also be appreciated.

Thank you!

 

[Min]

When deciding on which kiln wash recipe to use an important consideration is the type of kiln firing the shelves will be used in. Example would be the washes with 50:50 silica and kaolin that I have a pretty strong hunch is what most of the inexpensive kiln wash is that comes from ceramic supply places. If you used this in a salt or soda firing it would glaze your shelves so silica is a no go for those type of kiln firings so alumina hydrate and kaolin are often used as a shelf wash for those type of kilns.  Adding a tiny amount of feldspar would help if you have a kiln that has enough air movement to cause little bits of wash to become airborne and land on pots. This doesn't happen with electric kilns therefor there is no reason for it. What adding a feldspar would do would make the wash a little more difficult to scrape / grind off. 

BTW if you don't want to purchase Glomax just purchase EPK and calcine some of it to bisque temp and use that for the Glomax portion of the recipe. 

 

[Dick White]

As Min suggests, the feldspar doesn't add much for electric firings. I use that recipe in 5 different studios that I am associated with (including my own personal studio). 50% alumina hydrate (cheaper than alumina oxide), 25% EPK, 25% calcined EPK. If you are completely set on adding the slight amount of feldspar, the G200 that John mentioned was one of the more common potash spars available in the US at the time. It is no longer available (the mine ran out), but the reality is that any locally available feldspar, soda or potash, will suffice.

dw