Looking To Start Mixing My Own Glazes

[Guest]

I've read a few books and articles on the topic and its time for me to start experimenting. I'll admit though, its confusing.

 

Let me start with that  I fire ^6 electric and the first two glazes I want to start with is a clear to go over underglazes and a white liner for inside teapots and mugs.

 

Followed by these three starters (there are others I'm interested about to, later for that).

 

   

 

Coyote's Shino, Cedar Shino and Green Shino. (clicking on the image will bring you to each of glaze info on Coyote's site)

I know these are proprietary recipes and I'm not asking for that, they are just to give you a general idea of the direction I want to start with.

 

Here's my confusion lays. there are many different types and mesh sizes of Frits, Kaolins, Silica and so forth I'm not sure which would be good for me to start with. I also like the rivulets that calcium oxide offers.

 

I guess what I'm asking for is can someone guide me to a list or suggest which chemicals I should start with?

 

Thanks

 

 

[oldlady]

you are asking for a shopping list of chemicals, right?  we had this discussion with pugaboo awhile back and i remember advising her to look at the recipes  that appealed to her and notice what chemicals, actually, they are minerals, were seen most often.  i would be happy to give you the recipe for a white glaze that is from a very old book by george and nancy wettlaufer called "getting into pots".  it was written by a glaze chemist and for a pottery beginner.  the info and recipes are still just as good as ever.  he also suggests lists of items a potter will need.  yes, it is hilarious to see that way back in the early 1970s things could be purchased for so little money but that does not mean the book is laughable.

 

do not know why coyote has called the glazes you pictured shino.  just a marketing thing, i guess.  and what are you calling calcium oxide?  not something i have encountered by that name.   maybe you mean the hare's fur effect of rutile in a glaze?

 

you mention experimenting.  are you going to become a second glazenerd or are you just saying that you will test recipes to see which ones work for you?

[Callie Beller Diesel]

 

https://digitalfire.com/4sight/recipes/index.html

 

 

Digitalfire has a recipes section that has some good base glazes that are excellent starting points for testing. The materials used are uncomplicated, and I believe widely available in North America. I would choose a few of the clear recipes listed, knock together some samples and test to see what they look like on your clay and underglazes. Note with clear, application thickness is a huge factor.

Once you get a good clear worked out, it's a very simple matter to add some opacifiers for a white, and some magnesium and colourants to get satin matte surfaces like the glazes Coyote calls "shino." You can then start playing with variegators like titanium, or minerals like lithium to get fun blues and greens.. the list goes on.

[Guest]

@ oldlady I'm just looking for recipes that will work for me and I do have recipes for white and clear. I have no plans on becoming a second glazenerd.

 

To give you an idea of one of the things that I'm confused about are frits, there are

Frit 3195. 3124, 3110, 3134, 3249, 3269

Six different types of kaolin

4 different mesh sizes for silica

 

Most of the recipes I have suggest which frit but not the type of kaolin or size silica.

 

I don't think I want to order all 16 of the above items to get started, I guess I'm looking for a "good starter kit" of materials to get my feet wet.

[oldlady]

ok, i don't know all the numbers of the frits but the most common ones seem to be 3124 and 3134.  that is enough to buy unless you actually see those odd ones in the recipe you want to use.  these frits are brand name Ferro.  there do not seem to be any others in common use.  very old recipes may have other numbers but they will say what they are.  

 

in the USA, EPK, edgar plastic kaolin is good enough.  if they are identified more closely, look at the name, call your supplier and i bet they tell you to use EPK.

 

silica 325 is good.  you are making glaze so use 325.

 

of course, all the chemists in the forum may disagree.  maybe strongly disagree.  but.............these are the ones i have used for years and have not needed any others.

 

get 50 pound bags of each so you do not have to adjust to every change the supplier makes in the next few or more years.  and a 60 mesh sieve is good.  why struggle to refine something to 100 mesh if 60 works?

[Guest]

Thank you oldlady

[High Bridge Pottery]

Pretty much every glaze recipe you find will have a feldspar in, so what is the difference? In my opinion not too much but they all bring different things to the table.

 

Here is a pic from digital fire melting feldspars, you can see there are differences in the way they behave. 

 

Now which one should you choose? Probably worth getting a high potassium feldspar and high sodium feldspar and seeing which one works best for you.

 

Kaolins and ball clays will be relatively similar (like feldspars) to each other but all bring slightly different things to the table. Again it will be maybe trying a few out and seeing what works best. EPK seems the go to.

 

Silica, that will be there too. Mesh size, as fine as you can but 300 is good.

 

Frits, I don't have that much choice over the pond but 3134 and 3124 are common in john brits cone6 book.
 

For a calcium source I like whiting but a lot of people use wollastonite.

So for a basic clear you need a feldspar, silica, clay, frit and calcium source.

A source of magnesium oxide is nice too, talc or dolomite.

[MatthewV]

My glazes can (for the most part) be made with this shopping list I used to start my studio with.

 

Silica 2 bag

China Clay (EPK) 2 bag

Ball Clay (OM4) 1 bag

Potash Feldspar 2 bag

Neph Sy 1 bag

Talc 1 bag

Whiting 1 bag

Wollastonite 1 bag

G. Borate 1 bag

Dolomite 10 kg

Frit 3124 5 kg

Frit 3134 1 bag

Frit 3195 5 kg

Frit 4110      

Tin Oxide 2 kg

Cobalt Oxide 250 g

Cobalt Carbonate 2 kg

Titaninium Dioxide 5 kg

Copper Carbonate 5 kg

Chromium Oxide 2 kg

Red Iron Oxide 1 bag

Rutile 5 kg

Manganese Dioxide 1 kg

Zinc Oxide 5 kg

Zicropax 5 kg

Bentonite 1 kg

 

The quantity ordered somewhat reflects how often the materials are used.

[glazenerd]

Seeing as though I am home early, weather shut us down yet again.

 

Frit choices are made by application: high gloss, satin, matte, some for lower fire use, some higher, some boron based, others higher alumina. Application determines frit choice: to start out: 3110 and 3124 will get you going across a broad range.

EPK is the common kaolin used, OM4 ball clay is also popular; I prefer New Zealand Kaolin.

 

Chemicals:   Mahavir or Custer for potassium feldspar; KonaF3 (minspar) for blended, and Nep Sy for sodium feldspar. Custer is iffy.

                     325m silica for all glazes, 200 m silica if you are doing high fire in specific applications. (or clay bodies).

                     Dolomite for calcium and magnesium, and talc for magnesium

                     Lithium carb for straight lithium additions, or spodumene and petalite for lithium feldspar.

                     Gerstley borate ( or equal ) for boron based glazes/ lower melt temps 

                     Alumina Hydrate ( needed in rare instances).... 1/4lb is plenty.

                     Bentonite... glaze viscosity.... 1/4lb is plenty to start.

                     Whiting... calcium source.

                     Copper carb.  cobalt carb, red iron ox... will give you plenty of color to start... with some choice stains.

 

This short list will get you well down the road and give you a working glaze base.

 

Nerd

[Guest]

Thanks everyone, this is a lot to digest so I'm going to read this over a few times before I ask my next question.

 

Thanks Again.

[S. Dean]

RonSa,

 

To answer your one of your questions directly, the most frequently listed frits used in the glaze recipes from John Britt's Complete Guide to Mid-Range Glazes are 3110, 3124, 3134 & 3195. These four would cover what you would most likely need to get started. If you don't want to purchase all four, Glazenerd recommended 3110 and 3124 above and information below indicates that 3110, 3134 and 3195 are pretty similar.

 

 

While maybe tangential to your original question on frits, the following background information might be interesting:

 

• Here's a spreadsheet that shows the composition of the different Ferro frits used in ceramics. As you can see, they contain varying percentages of silica, alumina, boron, calcium, potassium and other items (e.g, zinc, lithium, etc).    http://www.ferro.com/NR/rdonlyres/AAC6D890-7E30-4E57-A61E-818DE097A898/0/potteryfrits2008.pdf

 

• Here's some information from the Ceramic Arts Daily Glossary on Frits

[Frits are] combinations of ceramic materials that have been melted to a glass and crushed/ground back to a powder, in order to give greater chemical stability and to eliminate toxicity resulting from water solubility of raw material. All frits are ground glass and are toxic in inhalation. FERRO 3124—high-alumina calcium-borate frit, gives greater strength in LT claybodies. FERRO 3134—calcium-borate frit often used as substitute for Gerstley borate in low-fire glazes when greater reliability and/or long-term insolubility and/or greater transparency are desired. Makes good cone 04 transparent glaze by itself. FERRO 3110 and 3195—Both very similar to 3134—run tests to determine which works best for your needs. Source: Clay: A Studio Handbook

 

While I've limited experience and expertise with glaze formulation, understand that glaze chemistry can impact the final glaze effect.  Here's an excerpt from Peter's Pottery that explains some factors that the New Zealand based author considers as he converts Cone 10 glazes to Cone 8.  (Full post here http://opopots.blogspot.com/2017/03/cone-8-glazes-change-and-new-clay.html).

 

I take notice of what the fluxes are, these can have a substantial affect on the oxides that are added to a glaze for colour. A glaze high in magnesium will have a lovely silky feel, but a cobalt blue may end up purple. Zinc will brighten copper or cobalt and may assist with glaze fit and durability, but it will also turn chromium oxide or chrome based stains brown. High levels of calcium will assist with making chrome reds or pinks, and will help make a physically strong glaze, but may "bleach" iron and give yellow rather than brown. And so on!

 

Factors like the type and amount of fluxes may provide a clue as to why a certain frit was used in the glaze recipe......desired alumina levels could be another factor.... and so on (as way more experienced and proficient members on CAD can elaborate).

 

Hope this was helpful,

 

-SD

[Min]

Perhaps we can make this a bit simpler for you Ron. First 2 glazes you want to make is a clear and a white. Good start. If you let us know what type of clay you are using, porcelain or stoneware, and if you have any problems with glaze crazing with your commercial glazes we could probably give you 3 or 4 clear recipes for you to try with minimal ingredients. The clears can be made white with zircopax (so add that to your list for sure, can also use tin but much pricier). Then do fit tests with your glaze tests to determine which one fits the bill there and overtop of your underglazes to check colour response there.  Roy and Hesselberth's book has a series of low to high expansion glazes as does the John Britt book I believe, or if you don't have those I can email you my series of clears.  Some people take a shot gun approach to finding a good glaze, some people like using glaze software to narrow the range down. 

[Guest]

Looks like I ran out of Likes

 

Thanks SD -  a lot of good info

 

Min,

I'm using ^6 stoneware and I haven't had any crazing problems with any commercial glazes I've used. I also have John Britt's Mid Range book and just returned The Ultimate Ceramic Artist's Guide to Glaze and Color by Brian Taylor and Kate Doody.

 

I'm a little analytical for a shotgun approach, can you suggest a glaze software?

 

Right now I'm trying to compile a grocery list of materials, More questions to come I'm sure

[GEP]

While you're making a shopping list:

 

You need an 80 mesh sieve. You really don't need any other meshes. But I recommend getting both a small test sieve and a full size sieve for 5 gallon buckets.

 

You need a scale that can measure down to 0.1 grams, and up to at least 2000 grams (more is better). These have gotten much cheaper in recent years.

[High Bridge Pottery]

Only me that uses a 120 mesh sieve? Sure can take some time getting it through.

[Roberta12]

RonSa, some very good points here.  Callie and Min both talk about testing.  See what fits your clay and firing schedule.  I went through years of trying to find a white stoneware that I loved.  I have actually settled on a porcelain that I love.  But I have tried a few clear recipes and always go back to the one in Mastering Cone Six.  I have had clears that craze.....so I stick with what works reliably for me and my clay.  My clear recipe works on the porcelain, the buff, and the dark red that I use.  I am not messing with success.  But you will find what works for you.  I use an 80 mesh screen and I have a 100 mesh that I bought by mistake.  I love my little digital scale.  It goes to 2600g.  I started with FF 3124,3134,3195  and added 3110 later.  Try to keep it as simple as you can to begin.  If you live close to a supply place, all the better. Then you don't feel like you have to "stock up". 

 

Roberta

[glazenerd]

Ron:

The list I gave you is a "starter"; it will get you into the basics of glaze mixing and formulation. You can take it for a test spin before investing large sums of money. The bulk of glaze recipes have the same basic ingredients: potassium, sodium, and calcium fluxes: with silica additions. Once you get your feet wet, you can move on to adding as needed. Truthfully you can easily start without any frits. Frits add fluidity, so you could find yourself fighting glaze run early in the game.

 

I use GlazeMaster 3.0 software for glaze and clay body formulation. Ron Roy wrote the clay body portion of this program. In addition, it has 4 different sets of formula limits for cone 6 glazes included in the program. I can program it for 10 different settings that determines how the information is viewed. It will also allow you to write your own formula limits; which I have done for porcelain clay bodies: working on stoneware now. Now a word of caution from a Glaze Nerd: glaze formulation is a rabbit hole which is hard to crawl out of once you fall into it.  

Nerd

[Joseph Fireborn]

I recommend watching this new video I saw a few days ago from NCECA. If you have no understanding of glazes it really is probably one of the best videos I have seen on the topic.

 

 

[Joseph Fireborn]

For the glazes in your OP picture. The first one can be replicated pretty easy using a glaze called Nutmeg. 

 

Here is an article showing a lot of the pictures of that glaze with other glazes over it. Article also contains the recipe. I have used nutmeg a lot in the past. It definitely looks like that first commercial glaze.

 

https://ceramicartsdaily.org/wp-content/uploads/2009/02/cmfeb03woodelectric.pdf

[Guest]

So here's my list as of now, any additions or deletions?

 

Nepphiline Syenite
FeldSpar Potash/ Mavhair #63
Silica 325
Frits 3134 and 3124
EPK
Dolomite

Lithium carb
Gerstley borate
Alumina Hydrate
Bentonite
Whiting
Wollastonite

Copper carbonate
cobalt oxide
red iron oxide
Rutile
Tin Oxide

I need:
Sieves (three different sizes where mentioned here on this thread)
A way to improve the ventilation


I have:
Scales
P100 respirators
1, 2 & 5 gallon buckets
Glove and googles (not sure if I need them)

[Roberta12]

Joseph F, thank you so much for posting that clip from Steve Loucks.  I was sitting behind the tallest man in the world and could not see the screen at all.  Afterward I searched to see if Steve had written a book, but alas, no.  I didn't even think about looking for the youtube video! 

 

Roberta

[High Bridge Pottery]

So here's my list as of now, any additions or deletions?

 

Nepphiline Syenite

FeldSpar Potash/ Mavhair #63

Silica 325

Frits 3134 and 3124

EPK

Dolomite

 

Lithium carb

Gerstley borate

Alumina Hydrate

Bentonite

Whiting

Wollastonite

 

Copper carbonate

cobalt oxide

red iron oxide

Rutile

Tin Oxide

 

I need:

Sieves (three different sizes where mentioned here on this thread)

A way to improve the ventilation

 

 

I have:

Scales

P100 respirators

1, 2 & 5 gallon buckets

Glove and googles (not sure if I need them)

 

If you're buying frits i'm not sure you need gerstley borate too. I like a 120 mesh but it does take a lot longer than 80 mesh. 

[Guest]

Thanks Joseph for the video and pdf

 

Joel, I had a feeling I could use one or the other, thanks.

[Min]

I would add Minspar (kinda have to say that given my nickname) plus maybe add zircopax. Cobalt oxide will give you specks in the glaze, if you don't want specks go with cobalt carbonate. Careful on the rutile you buy, there are different grades of that, I like the fine ceramic grade (you can use titanium dioxide if the rutile you get leaves a muddy colour to your glazes). Gerstley is cheap and some recipes are difficult to adjust with frits to get enough boron into them, I would get a bit of that plus the frits. For the bentonite, since you will be making clear glazes go for the white bentonite, I think it's sometimes called Volclay? can get specks from the regular grade of bentonite. Yes, on the gloves, good idea to wear them when working with glazes. We all have our preferences for screen size, I like 80 mesh, doesn't take long to run a glaze through that size. If you already have kiln wash you could leave the alumina hydrate, since you are not working with porcelain you won't need that for adding to wax resist in pot galleries and alumina in the glaze is easy to get with the epk. Your P100 is a fitting mask/respirator and not one of those paper disposable ones right? Holy cow, this sounds way more complicated than it should, hope you can muddle through all this 

[glazenerd]

That list works for me... Nerd