Frit Substitution Chart + Orton Cone Charts + Kiln Wash Recipes

[Min]

Frank Gaydos was generous enough to allow us to post his Frit Substitution Chart here on the forum. It contains a chart of some common frits with substitutions plus a lengthy list of frits with their composition. Included are Ferro, Hommel, Pemco, PotClays and PotteryCrafts. I've added a link to the DigitalFire reference list of frits to include Fusion and other frits not included in the Frank Gaydos pdf. (direct permission from the author, Frank Gaydos, obtained prior to posting here)

Frank Gaydos Frit Substitution Chart Frits.pdf

edit: posting pdf's is new here, it looks like you need to be signed in to open the pdf link

[Fred Sweet]

Min-

The link for the pdf from Frank Gaydos doesn’t work. Is something missing?

Edit: never mind. My problem. I copied too much information because I didn’t see the hot link on my phone.

Apologies to all.

Regards,

Fred

 

Edited October 15, 2019 by Fred Sweet

[Min]

Seems we are shifting between Celsius and Fahrenheit a fair bit so I'm adding Links to Orton Cone Charts in both to save people looking them up who might not be fluent in both. If anyone needs it there is some really good information regarding the behaviour of cones and how the rate of temperature increase during the final 1 1/2 - 2 hours of the firing effects the final cone, also on the links below.

Orton Cone Chart in Fahrenheit

Orton Cone Chart in Celsius

edit: There seems to be an error in the information regarding small cones in the above information to the right of the charts. "Typically, small cones will deform 7-10 degrees C earlier than a self-supporting cone, so the temperature values for a self-supporting cone can be used to determine an equivalent small cone temperature by subtracting 7-10 degrees C (or 12-18 degrees F)." This contradicts what it says in the Orton Cone Firing Booklet: "While not recommended, Orton Small Cones can also be used on the kiln shelf in place of larger cones. Because they are smaller, higher temperatures and more heat are required for them to bend (see page 19). When used in this way, the Small Cones require mounting in cone holders or plaques." 

Edited May 27, 2020 by Min

[liambesaw]

Here's a chart with both:

[Hulk]

Recall we received clarification from Orton on small vs large cones: 

      https://community.ceramicartsdaily.org/topic/21668-kiln-sitter-cone-for-witness-cone

The website was corrected (the .pdf was ok)

      The small cone description has been changed on Orton's website, now reads (emphasis added) "Small Cones used on the kiln shelf deform at about 9°F after Large or Self-Supporting Cones of the same number."

My take is still (mostly) repeatability - how the glaze and clay behaves when cone is bent thus, hence difference between large and small cones matters when a) switching to the other cone type (I like the small ones) and/or b) when sharing firing info with others.

[Min]

I do remember that thread Tom, it's what made me question what the info on the cone charts says. The blurb with the charts is reading the opposite of what the Orton Booklet is, hopefully they will change the oversight. I emailed them, will update my post if they change anything.

[Min]

There seems to be a fair few people lately asking about kiln wash. I'm going to pin this thread so it should be easy to find going forward. If you have a recipe and care to share it I thought a thread just dealing with kiln wash would be a good idea.This is what I have been using for about the past 20 years (electric kiln), mixed with enough water to make a runny yoghurt consistency, applied with small roller or house painting brush to high alumina shelves. Measured by weight.

alumina hydrate 50

calcined epk 25 (aka glomax) 

epk 25

[liambesaw]

That's what I use as well, works very good.

[Mark C.]

alumina hydrate 50

calcined epk 25 (aka glomax) 

epk 25

 

Yada yada yes for me as well

[oldlady]

it is terriffic.

[Denice]

I use the same mix, it works great!!!!    Tony the Tiger     I had some sugary cereal last night I think it is messing with my head.     Denice

[Magnolia Mud Research]

I use epk out of the bag and alumina-hydrate, equal amounts by volume (use a cup); fire cone 10R.  

[Mosey Potter]

I got this recipe from Ron Roy many years ago and it's great:

20 EPK

20 OM4

60 Alumina

I brushed it on with a sponge brush, but Ron tells me he uses a garden sprayer to apply. 

[Mark C.]

Ball clay for me makes it to harder to remove I feel-I took out ball clay from wash reciepe in the 80s

I love the EPK alumina mix posted above.

[Russ]

https://insight-live.com/insight/share.php?z=K5hHzDs2Kr

Ive started using this last year. Its a zircon based wash. I dont think ill ever go back to the alumina hydrate/epk wash

[Bill Kielb]

1 hour ago, Russ said:

ve started using this last year. Its a zircon based wash. I dont think ill ever go back to the alumina hydrate/epk wash

Agreed - my experience, zircon based washes are way better. Most folks don’t even think about their old wash recipe after using A decent zircon product. Lee’s is zircon based I believe.

[liambesaw]

I used that zircopax recipe and it did not work for me, it would always flake off after the first firing and glaze drips didn't come off cleanly like with the alumina.  Got tired of reapplying and just switched to the alumina one.  Still cracks after a while but nowhere near as bad.  I really wanted the zircopax one to work because I have a 50lb bag and it was way cheaper than alumina.

Edited October 17, 2020 by liambesaw

[Bill Kielb]

53 minutes ago, liambesaw said:

I really wanted the zircopax one to work because I have a 50lb bag and it was way cheaper than alumina.

The Lees is so solid I can wash both sides and simply flip shelves as necessary to keep them straight. Wash stays on tight. Pricey though but great in a studio.

[Mark C.]

I love milled zircon-I use  some of it in my propriety salt wash formula

[Marcia Selsor]

On 5/27/2020 at 12:12 PM, liambesaw said:

Here's a chart with both: https://www.pinterest.com/pin/534943261960144493/