Can Pottery Glaze Be Frozen - Pottery Crafters

When living in cold climates where freezing temperatures are common, your glaze may be left outside for delivery or other reasons. You may wonder, Can Pottery Glaze Be Frozen? If you’re not sure what happens when pottery glaze freezes, you’re not alone. A lot of people don’t know the answer to that question.

The short answer is yes. But it’s important to know that not all pottery glazes can withstand freezing equally. Some glazes can withstand freezing much better than others. The reason for this difference is the composition of different glazes and how well they can withstand what happens when water turns to ice.

Read on for more information about what happens if glaze freezes, how to know if your glaze was frozen, how to reclaim frozen glaze, and more.

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What Temperature Does Glaze Freeze?

Most liquid pottery glazes don’t freeze at 32℉ (0℃). Usually, 28℉ (2℃) is the tipping point for them to start freezing. At 0℉ (18℃), the glazes will be in a solid freeze.

If you are worried about your pottery freezing, you can take some preventative steps. For example, you can insulate your pottery during transport or ship your pottery during warmer months. By taking these simple steps, you can help ensure that your pottery glaze arrives safely and without any damage.

What Happens When Pottery Glaze Freezes?

For one, If the glaze is in liquid form, it will expand when it freezes and could damage the container.

Also, for the pottery glazes to be stable, they need suspending aids such as CMC gum, Veegum, and Bentonite. The freezing process can degrade the suspend aid in the glaze and ruin the glaze, especially in a solid freeze.

an image of frozen deep firebrick and sandstone glaze — Frozen Amaco Deep Firebrick and Coyote Sandstone glaze

On the plus side, some glazes can withstand freezing better than others. For example, the newer glazes can withstand freezing better than the older glazes because of their suspending agents. In addition, the newer deflocculating agents (suspending aids) are more stable and can withstand a wider temperature range. Also, the finer milled particles in the commercial glaze formulas bind better with the water and prevent easy separation when freezing.

If you’re unsure if your liquid glaze is freeze-resistant, it’s best to test it out on a test tile before applying it to your entire piece.

How Do You Know if Ceramic Glaze Has Been Frozen and Thawed

If your ceramic glaze has been frozen and thawed, the materials in the liquid will have separated. This is because when water freezes, the molecules expand and separate from the ingredients in the glaze. As a result, the ingredients will settle and leave the liquid on top.

an image of thawed glaze — Thawed Coyote Sandstone glaze

Also, look at the color of the glaze. Frozen and thawed ceramic glazes can tend to be lighter in color than those that have not been frozen. If you see this in your glaze, it has likely been frozen and thawed.

How to Reclaim Frozen Glaze

Reclaiming frozen glaze is simple, once the glaze thaws to room temperature. The best way to mix your glaze is with an Electric Mixer to ensure the glaze is back to an even consistency. You can also add a Suspendaid or CMC Gum to your glaze, which will help the glaze adhere to the pottery with even consistency.

an image of mixing thawed coyote sandstone glaze

After mixing, you can run the glaze through a Strainer. If you’re unsure of how the finished product will look, you can always apply it to a test tile and fire it in the Kiln. With this method, you can be sure that your glaze will come out looking professional and beautiful every time.

Can Pottery Glaze Be Frozen and Reused

The answer is yes and no. First, freezing and thawing will not ruin the glaze for many commercial pottery glazes. But it is important to note that thawing the frozen glaze will NOT cause the ingredients to re-suspend on their own.

Second, freezing may ruin the pottery glaze because of the different ingredients depending on the type of suspending aids used in the glaze. Suspend aids like CMC gum can break down and degrade when frozen and thawed.

I Tested a Few Frozen Brushable Glazes:

It’s important to test the thawed brushable glaze on a test tile before applying it to your entire piece. I was surprised at the results.

Frozen Amaco Pottery Glaze

If your glazes freeze, the liquid will separate out from the glaze particles. Once your glaze thaws, mix thoroughly. A mixer and a sieve may be required to bring the glaze back to a brushable or dipping consistency. See Amaco Frozen Glaze Advisement.

I have the Amaco Deep Firebrick Glaze that I froze on the left and not frozen on the right.

an image of amaco deep firebrick glaze test tile frozen on the left and not frozen on the right — Amaco Deep Firebrick glaze test tile was frozen on the left and not frozen on the right

I found that the glaze had reconstituted fine, with no difference in look or texture.

Frozen Mayco Pottery Glaze

The Mayco technical lab conducts freeze/thaw tests on its glaze products. They have determined that glazes can withstand numerous freezes without negative results. See Mayco’s Freeze Advisement.

I froze the Mayco Lavender Mist glaze. The lavender mist test tile was frozen on the left and not frozen on the right.

an image of mayco lavender mist glaze test tile frozen on the left and not frozen on the right — Mayco Lavender Mist glaze test tile was frozen on the left and not frozen on the right

After being fired. The glaze that was frozen looks the same and has the same texture as the glaze that was not frozen

Frozen Spectrum Glaze

If the Spectrum Glazes freeze, you can thaw and mix very, very well.

The Spectrum Sangria Glaze test piece was frozen on the left and not frozen on the right.

an image of spectrum sangria glaze test tile frozen on the left and not frozen on the right — Spectrum Sangria glaze test tile was frozen on the left and not frozen on the right

I found no difference in the look or texture of the glaze after being fired to cone 6 in the kiln.

Frozen Coyote Glaze

I also froze the Coyote Sandstone Glaze with the same results.

The glaze that was frozen is on the left, and the glaze that was not is on the right.

an image of coyote sandstone glaze test tile frozen on the left and not frozen on the right — Coyote Sandstone glaze test tile was frozen on the left and not frozen on the right

I was pleased with the results of the thaw tests. The glaze ingredients in all the glazes withstood a hard freeze for over a week.

Can Pottery Glaze Be Frozen With Dipping Glaze?

Because most Dipping Glazes generally do not contain suspend aids, you can freeze them. Then, thaw to room temperature and blend really well with a mixer.

Then run the glaze through a Sieve. Mesh Size 1/50″ is good.

It’s best to check the label to ensure your dipping glaze ingredients do not have suspend aids like CMC gum that can degrade in the glaze when frozen. The glaze manufacturer will indicate that the dipping glaze will remain suspended longer and or take a little longer to dry. For example, Coyote Dry glazes contain the same ingredients as their wet glazes; therefore, they contain suspend aids.

Can Underglaze Be Frozen?

Underglazes contain Water, Colorants (stains or iron oxide), and Clay (Kaolinite, also called Aluminum silicate) and have a little Frit (mixture of silica and flux) to help the underglaze fuse to the pottery. Underglaze also may contain suspend aids such as CMC, Veegum, and Bentonite. The amount of clay and suspend aids depends on the underglaze manufacturer.

If the Underglaze contains Suspension aids, it can degrade after being frozen. This would also depend on the type and amount of suspension aids used in the underglaze. In some cases, underglaze can be more vulnerable to being ruined when frozen. The liquid in the underglaze will separate like this underglaze.

If the underglaze has been compromised, the texture and color will change like this handle. The red underglaze was frozen, and the black was not.

an image of frozen red underglaze not frozen black underglaze on handle — On the handle, frozen red underglaze – not frozen black underglaze

If you know the underglaze was frozen, mix it really well. An Electric Mixer is best. Apply the underglaze to a test tile before using it on your piece. Use the same precautions as you would with brushable glazes. If you live in a colder climate, be aware of your delivery time, watch the local weather or wait until the warmer months.

To be cautious, you can ask the manufacturer, or don’t allow your underglaze to freeze.

Can Wax Resist Be Frozen?

If Wax Resist freezes, the only thing you can do is throw it away. It is very sensitive to the cold, and the chemical changes in the ingredients from freezing are irreversible. If you live in a colder climate, it is best not to order wax resist in the cold weather months and wait for the warmer months.

Can Glaze on Bisqueware Pottery Be Frozen?

Since Bisqueware pottery is created through a process of firing clay. Bisque Firing removes the water molecules from the clay, turning it into a ceramic material with an open pore structure. Once the glaze is applied and dried, it can withstand being frozen without damage because there is no liquid to separate from the glaze ingredients.

However, glazed bisqueware may get compromised if frost from the water molecules in the air settles on your glaze. This would also depend on what glaze you are using and the effect it would have on your glazed piece. Generally, it is safe to assume that freezing your glazed bisque ware will not damage it.

Summary

Although pottery glaze can be frozen, it is always best to check with the manufacturer to see if their pottery glaze ingredients can withstand a hard freeze. Glazes that contain suspend aids, such as CMC gum, are more likely to be damaged from being frozen.

If you live in a colder climate, be aware of your delivery time, watch the local weather or wait until the warmer months to order your glazes. And remember, if you are worried about your wax resist being damaged by the cold, it is best to avoid being delivered in the winter months. While freezing pottery glaze can be done successfully. In some cases taking caution and doing your research is always the best approach to ensure that your pottery looks its very best!

FAQ

Can Glaze-Fired Pottery Be Frozen?

Pottery can be frozen because it is now more of a glass-like substance after being glazed and fired in the kiln. I have put my pottery pieces in the freezer many times without problems. However, It is important to note that not all clay bodies and glazes are created equal. Some pottery may crack or break if frozen.

If you are unsure whether or not your frozen dish will crack, it is always best to err on the side of caution and test freeze a piece of your pottery.

How Do You Reclaim and or Dispose of Pottery Glaze?

Here are a few Glaze Reclaim tips to help lessen the environmental impact. You can add a stabilizer like Suspendaid. You can mix the glaze well and run it through a sieve. You can also add water or combine glazes.

For more detailed information, go to how to Properly Disposing Of And Recycling Glazes.

Can Pottery Clay Be Frozen

When clay freezes, the clay particles push apart as the water freezes and becomes unevenly distributed. But don’t worry, you can still use the clay for making pottery!

However, the clay may take a long time to thaw, and you will need to do some extra wedging to get the clay to a workable state. This article Can Pottery Clay Be Frozen to give you some tips on how to handle frozen clay and still create beautiful pottery pieces.