How To Mix a Ceramic Glaze From Scratch

 
A red iron oxide glaze in the process of being run through a Talisman Glaze Sieve.

A red iron oxide glaze in the process of being run through a Talisman Glaze Sieve.

 

This post is an overview of how to mix a ceramic glaze from dry ingredients, including the tools, techniques and procedures to get you started.

Whether you buy a pre-mixed dry glaze or weigh each ingredient, there are a lot of advantages to mixing your own glaze:

  • Save money: Mixing glazes in your studio is always cheaper, sometimes as much as 80 to 90 percent cheaper than bottled glaze.

  • Customize: Learn how to modify slips and glazes to suit your kiln and clay bodies.

  • Learn glaze chemistry: Even a bit of info can help you get the results you want.

A variety of our favorite glaze recipes are posted here, and there are lots of websites and books with glaze recipes. There are endless amounts of glaze recipes, so if you are new to this, just start with one basic one such as a glossy clear. There are also pre-mixed, dry glazes which are effective and still save some money over buying bottled glazes.

Keep reading for the complete how to instructions.

Table of Contents

  • Glaze Mixing Tools and Accessories

  • How To Mix Glazes From Scratch

  • Testing and Storing Glazes

  • Summary

Glaze Mixing Tools and Accessories

Here’s what you need to mix glaze in your studio:

How To Mix Glazes From Scratch

  1. Review recipe.

    Check to make sure you have enough of each ingredient. It can be helpful to calculate and write out the amount of each material, to be used as a checklist.

  2. Prepare work area

    Put on a dust mask, clean your scale and work area. Get your materials, buckets, and scoops together.

  3. Zero scale

    Place your measuring pan or bowl on the scale and turn it on. If needed, press the tare button so that the scale is zeroed out.

  4. Weigh ingredients

    Weigh each ingredient (this is where your checklist is handy) and put them in a dry bowl or bucket. After measuring all the ingredients, mix the dry ingredients together. Some glaze ingredients, such as bentonite, are prone to clumping so it is important to mix everything dry first.

  5. Add to water and mix

    Add the mixed glaze materials to water and mix until it is thick cream or buttermilk consistency. An electric drill with a proper mixing blade greatly speeds up this process. A large plastic scraper will dislodge material from the side of the bucket. Once all the dry ingredients have been mixed with water, you can remove your mask if desired.

    Note: it’s best to add glaze materials to water. If you add water to a bucket of dry materials, it’s hard to get everything in the bottom corners mixed.

  6. Sieve and homogenize

    Prepare another clean bucket with a sieve, preferably a fine 80 mesh sieve. Run the glaze through the sieve this first time, to break up any clumps. A brush can help push material through the sieve, or a Talisman Glaze Sieve is a tool made specifically for mixing glaze into 5 or 10 gallon buckets.

    Then, clean the bucket where you will be storing the glaze. Run the glaze through the sieve a second time into this clean bucket.

  7. Test glaze consistency

    Glazes are typically mixed to a specific gravity, which measures the amount of dissolved solids in the water. Usually glazes are around 1.50, which means 50 parts dissolved solids to 100 parts water. Keep records and mix the glaze to a consistency that works for you.

    Specific gravity can be measured with a specialized (but fragile) hydrometer, or you can use a graduated cylinder on your scale. With your cylinder zeroed out on the scale, pour in 100ml of the mixed glaze and check the weight. Add water as needed, and mix.

  8. Label and store

    Glaze containers and lids should be labeled with the name, temperature, and any other information that will help you. Laminated, waterproof labels are best but packing tape can also protect a label for some time.

Testing and Storing Glazes

Testing Glaze

It is helping to make a test tile of a glaze, on each clay body you use. Vertical test tiles such as tubes from an extruder are best, as they show how a glaze will “move” with gravity. Dip your test tile with one and two dips to show how different thicknesses of glaze affect the color.

Some studios choose to make a test tile with each batch of glaze. But if you are careful to mix the glaze accurately to a similar specific gravity, and your firings are repeatable, you should get roughly the same glaze results each time. There are no guarantees with glaze though. It is important to keep records, both in a glaze book and a kiln log, in order to get standardized results. But, glaze materials do change over time so as necessary you can make new test tiles.

Storing glazes

Glazes can be stored in sealed containers or buckets almost indefinitely. Most glaze ingredients are inorganic and will not rot. But some ingredients, such as bone ash, can cause some rotting smells. To avoid this, make sure the glaze is mixed with some frequency. If the odor persists, you can add a trace amount of copper to any glaze (even white glazes!) without affecting the color. Copper is an anti-fungal and can cut down or eliminate odor. Read our post on that here.

Remixing glaze

As they are used, glazes do lose some moisture to evaporation and bisqueware can suck extra water out of the glaze mix. It can be helpful to mix and then do a quick visual check of the glaze. If necessary, you can re-check the specific gravity and add water. If a glaze seems thick or is glopping onto your pieces, it’s definitely time to check it and probably add water.

In addition, when I mix glaze, I will usually run all the old and new glaze through a sieve. Small bits of bisque and other contaminants can fall into a glaze bucket. When I’m using it, I want to know what I’ve got in that bucket. It does take extra work but having a double-sieved, homogenized glaze will result more even glaze application and hopefully, better results.

Summary

This post has covered a basic overview of mixing glazes from scratch. It covered the tools, techniques, and a few helpful hints to mix and store glazes. If you can follow a recipe, you can mix glaze. There is an overwhelming amount of glaze info out there, but if you start with just one basic recipe and grow from there, you will be a glaze master in no time and you will be able to customize and mix glazes to suit your own needs.

If you are looking for more info on mixing glazes, the glaze books by John Britt are some of the best resources.

The Complete Guide to Mid-Range Glazes

Buy at Bookshop.org

Buy at Amazon

The Complete Guide to High-Fire Glazes

Buy at Bookshop.org

Buy at Amazon

Questions or comments? Let us know in the comments.

The Best Glaze Mixing Accessories For Ceramic Studios

Mixing your own glazes from scratch is cost-effective and allows you to customize glazes to suit your studio. Whether you are mixing a powdered glaze with water, or weighing each ingredient and starting from scratch, having the ability to mix glazes opens up possibilities in your studio. You don’t need a huge set up to get started, a few simple tools and buckets are all you need. Below are reviews of our favorite glaze-mixing accessosories.

This list includes:

  • Drills

  • Immersion Blenders

  • Sieves and Strainers

  • Dust Protection

  • Mixer Blades

  • Scales

Drills

A drill is one of the most important glaze-mixing tools. Sure, you could get a big whisk or paddle and mix your glaze by hand, but….I wouldn’t recommend it.

For a drill, my favorite is the Milwaukee M12 3/8” Drill. It’s compact, well built, and affordable. And it has enough power to mix a 5 gallon bucket and just enough power to mix 10 gallons of glaze. It’s also cordless, which I find easier to use in the studio but you do sacrifice some power and you’ll have to deal with recharging batteries.

There are a lot of drill options out there, with all sorts of options, battery and cord styles. For more info, check out the Studio Manager Cordless Drill Review and our Corded Drill Review

Immersion Blender

For small batches of glaze, especially test batches, an immersion blender is a great tool. Designed for kitchen use, these definitely have enough power to hold up in the studio. I would just make sure you have one dedicated for studio use and a separate blender for kitchen use.

For an immersion blender, I have never noticed much of a difference between name brands and generics. You just want a blender that will work and get your glaze mixed. A great option for this is the Mueller Austria 9 Speed Immersion Blender. You probably don’t need all those speeds, but it does have a turbo button which speeds things up. And at around $30-35, this is one of the more affordable immersion blenders on the market.

Sieves and Strainers

A sieve is an important part of mixing glazes. A sieve insures that particles are broken up and that the ingredients are evenly distributed in the glaze. Proper mixing and straining also reduces glazes flaws, generally resulting in a more even glaze. If you are mixing glazes from dry powder or from scratch, you must run them through a sieve. Generally, I have a variety of sieves in the studio including a simple kitchen sieve, a smaller tea strainer, and specialized tools such as the Talisman Rotary Sieve.

The Talisman Rotary Sieve.

The Talisman Rotary Sieve.

Talisman Rotary Sieve

The best tool for sieving glazes is the Talisman Rotary Sieve. This is a large, hand-cranked sieve that will fit over a 5 or 10 gallon bucket. It has three brushes which can be removed for cleaning (or replaced if worn out) and removable screens. This allows you to choose which size of mesh to screen your glaze. Typically, this is done somewhere between 80 to 120 mesh. The Talisman Rotary Sieve is expensive, usually $200-250, but it makes short work of the sieving process and the brush system helps break up smaller particles, resulting in a uniform glaze batch. It’s an incredibly well-built tool and if handled with respect, it will hold up for decades of use. Talisman Rotary Sieves are typically only available from speciality clay supply stores, so shop clay stores online or contact your local clay supplier.

Talisman Test Sieve

Talisman Test Sieve

Talisman Test Sieve

Another option, especially for glaze test batches, is a cup sieve such as the Talisman Test Sieve. These small sieves are stackable, come in a variety of mesh sizes from 5 to 250, and are really well built. You probably just need one or a few, I’d suggest an 80 to start and in my own studio, I generally just use 40 mesh for a rough sieve and 80 mesh for a fine sieve.

Cuisinart Fine Mesh Steel Strainer

Cuisinart Fine Mesh Steel Strainer

Fine Mesh Steel Strainers

Another useful tool is a kitchen steel mesh strainer. These are not fine enough for a final glaze strain, but the wider mesh is still useful for quickly breaking up chunks of material. They are also great for quickly processing glaze in order to remove any bisque chunks or other small things.

When mixing glaze, materials such as Wollastonite, Soda Ash, Borax, Zinc Oxide, and most oxides used for colorants and others must be run through glaze sieve (usually 80 mesh), but if you start with a kitchen sieve, you’ll get the big chunks out quickly and can have an easier time with the glaze sieve. Smaller strainers such as a tea strainer are also useful for quickly running an underglaze or small batch through mesh. Sometimes, a simple mix and strain can bring a thickened glaze, underglaze, or slip back to being easy to use.

A great option for a kitchen steel mesh strainer is the Cuisinart 3 pack of Fine Mesh Metal Strainers. The all-metal design makes it easy to clean and maintain, and the variety of sizes will help with most small to medium glaze batches, or if you need to quickly strain a chunky material before running it through a finer mesh. There is also a link to a similar product by ExcelSteel at Home Depot.

Recommended Sieve Sizes

Here’s a useful chart of recommended sieve mesh sizes to use when mixing glaze, slip, and casting slip.

Suggested Sieve Size.jpg

Face Masks and Dust Protection

Dust protection and personal protection equipment is vital when mixing glazes. The main worry is any sort of airborne particles, particularly the finest particles such as silica. Repeated exposure to these particles, found in all dry glaze and clay materials, can lead to respiratory problems. Some also choose to wear plastic gloves when mixing and using glazes. The best thing when thinking about gloves is to assess your own risk and work to understand what is in glazes and what may be dangerous.

Respirator

The 3M Respirator

The 3M Half Facepiece Respirator with P100 cartridge style filters.

The best dust protection is a respirator. These devices are reusable, fit on your face more tightly than a dust mask, and the filters can be replaced as needed. Although moisture can build up, I find them to be more comfortable than a paper or surgical type mask, and they definitely provide a tighter fit. One drawback though, is you can’t really talk to anyone while they are on.

For a respirator, I have always used a 3M half facepiece respirator with P100 filters. They are usually widely available, so it’s easy to find replacement filters in stores or online. It can be hard to tell if the filters are getting full of dust, so I generally buy new filters every 6 months. It can round around $20 for new filters, but as someone who works full time in ceramic studios, I don’t want to take any risks with my lungs.

If you don’t want to get a respirator, at the very least get a N95 or KN95 mask and wear it whenever you are working with dry glaze or clay materials. Also be aware, fine particles can remain in the air for a while, use caution when mixing and try to keep dust out of the air. For more, see our complete article on dust masks for studios.

Mixing Blades and Paddles

The right mixer blade will make your glaze and slip mixing quick and efficient. It’s best to stock different size mixers for mixing different amounts of glaze. These are the mixing blades I stock in my own studio.

The small Jiffy LM10 Mixer Blade

The small Jiffy LM10 Mixer Blade, also called a laboratory mixer.

Small Mixer Blade

To mix pint jars and small cups, the Jiffy LM10 Mixer Blade is just the right size. It’s 10 1/4” long with a 1 1/4” head.

 
Helix mixer blade for 1 to 2 gallon buckets

Helix mixer blade for 1 to 2 gallon buckets

MEDIUM MIXER BLADE

For one to two gallons, I prefer a helix mixer designed for 1 gallon buckets. It’s cheaper than a metal blade but it can really mix. As long as you don’t grind the plastic blades against buckets, these economical blades should last for years and also work well for jobs such as mixing plaster.

 
The Jiffy ES Mixer Blade for 2 to 10 gallon buckets of glaze.

The Jiffy ES Mixer Blade for 2 to 10 gallon buckets of glaze.

LARGE MIXER BLADE

For 5 or 10 gallon buckets, the Jiffy ES mixer blade is the way to go. It has a 20 1/2” long, 3/8” shaft and the head is 3 3/4” wide. It’s perfect for 5 gallon buckets and it will mix up to 10 gallons as long as you have a strong enough drill (usually a corded drill or a higher powered cordless drill)

Scales and Accessories

A scale is a must-have for mixing glazes. An accurate, durable scale is a great investment. My favorite is the Oxo 11 Pound Scale. To read about other scale options, the Studio Manager scale review can be found here.

The Oxo 11 Pound / 5 KG Scale is great for home or studio use.

The Oxo 11 Pound / 5 KG Scale is great for home or studio use.

The Oxo 11 Pound Scale is designed for kitchen use but it’s a just as useful in the studio. It runs on 4 AAA batteries, and is accurate to 1/8 ounce or 1 gram. A great feature is the pull-out, light up display that allows you to use the scale with larger bowls. The scale has four buttons: a lb/kg toggle, light switch, zero button, and power. The top stainless steel platform can also be removed for cleaning. This scale can accommodate up to 11 pounds or almost 5 kilograms at a time. It’s an incredible amount of features in a scale that typically costs about $50.

Ohaus Maxi-Scoop Bowl

The Ohaus Maxi-Scoop bowl.

The Ohaus Maxi-Scoop bowl.

The Ohaus Maxi-Scoop is my favorite bowl to use when weighing dry ingredients. Made of polypropylene, it is 10 inches wide, has a pouring spout, and is durable and easy to clean. It holds a lot of material, typically up to about 2500 grams, and the open, wider design makes it easier to use in my opinion. Of course, you can use any sort of bowl to measure dry ingredients, but this one just seems to be ideal for scales and it’s the one I reach for first when I’m mixing glaze.

Metal Scoops

metalscoop.jpg

A quality metal scoop makes working with dry materials so much easier. In a pinch, I’ve repurposed small yogurt containers as scoops, but a durable, long-lasting metal scoop is better. For large storage bins or bags, you might get a scoop for each material. Or if you have a collection of 2 to 4 different sizes, you can get through most glaze batches without contaminating between materials, and then wash the scoops after glazing. For really strong ingredients such as red iron oxide, I leave small scoops in each bin so I don’t have to clean the scoops each time I use them.

Wrap-Up

This post has listed my favorite tools and accessories for use when mixing glaze, including drills, immersion blenders, sieves and strainers, dust protection, mixer blades, and scales. It may seem like a lot of stuff, but each tool has it’s role to play in the glaze-mixing process. If you are new to mixing glaze, start with the basics such as a scale, dust-protection and maybe just a wooden spoon, and go from there. You can always add tools as needed.

What are your favorite tools to use when mixing glaze? Let us know in the comments.