Can You Refire Pottery If the Glaze Went Wrong?

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If you open your kiln after a glaze firing and the pottery doesn’t look the way you expected, it can be tempting to simply put it back in the kiln.

Sometimes, refiring pottery can help. But it isn’t always the best solution, and another firing can sometimes make an existing glaze problem worse.

Whether you should refire depends on what went wrong, what glaze you used, and what firing temperature the piece has already experienced.

Can You Refire Pottery After a Glaze Firing?

Yes. Pottery can be fired again after a glaze firing.

Refiring is sometimes used when a glaze appears underfired, when a decorative finish needs another firing, or when a potter is intentionally trying to change the surface.

However, you should first identify the problem.

If the glaze problem was caused by incorrect application, contamination, incompatibility, or an unsuitable firing schedule, simply firing the piece again may not fix it.

When Does Refiring Make Sense?

Refiring can make sense when the glaze hasn’t fully matured or when the firing itself appears to have been incomplete.

For example, you might consider refiring if:

• The kiln did not reach the intended temperature
• The firing was interrupted
• The glaze appears clearly underfired
• A compatible decorative layer needs another firing
• Testing shows that the glaze can safely tolerate another firing

Before refiring, determine why the first firing didn’t produce the expected result.

What Is an Underfired Glaze?

An underfired glaze hasn’t received enough heatwork to develop as intended.

Depending on the glaze, it might look different from the manufacturer’s sample, remain unusually dry or rough, or fail to develop its expected surface.

If you know the kiln didn’t reach the required temperature, a carefully planned refiring may sometimes improve the result.

But don’t automatically assume that every unattractive glaze is underfired.

A glaze can look different for many other reasons.

Can Refiring Fix a Glaze That Is Too Dry or Rough?

Sometimes.

If the glaze is underfired, additional appropriate heatwork may allow it to mature.

However, you need to stay within the recommended firing range for the glaze and clay.

Firing at a higher temperature than the materials are designed for can create additional problems.

The goal isn’t simply to make the kiln hotter. The goal is to use the appropriate firing schedule for the materials.

Can You Refire a Glaze That Is Too Thick?

Refiring usually isn’t the first solution to an overly thick glaze application.

A glaze applied too heavily can produce problems such as running, crawling, blistering, or other surface defects.

Another firing may cause the glaze to become even more fluid.

Before refiring, consider whether the glaze thickness or application was the original problem.

What If the Glaze Ran?

Be careful about refiring pottery with a glaze that has already run.

A runny glaze can move even more during another firing, especially if the second firing gives it additional heatwork.

It can potentially damage kiln shelves or cause the piece to stick to the shelf.

If the glaze has already flowed significantly, simply firing it again may not be the safest or most useful solution.

Can Refiring Fix Pinholes?

Sometimes, but not always.

Pinholes are small surface openings that can occur for several reasons, including glaze application, firing conditions, clay body characteristics, and gases escaping during firing.

In some cases, another firing can help heal minor surface defects.

In others, the underlying cause remains and the pinholes return.

If pinholing is happening repeatedly, it’s better to investigate the firing schedule, glaze application, and materials instead of repeatedly firing the same piece without making changes.

Can Refiring Fix Crawling?

Usually, simply refiring isn’t the best solution for crawling.

Crawling occurs when glaze pulls away from parts of the ceramic surface instead of forming a continuous coating.

Possible causes include:

• Glaze applied too thickly
• Dust or contamination
• Poor adhesion
• Improper glaze preparation
• Incompatible glaze application

Adding more heat doesn’t necessarily solve the cause.

What If the Glaze Color Is Wrong?

This is one situation where refiring may or may not help.

Glaze color can change because of firing temperature, kiln atmosphere, glaze thickness, cooling conditions, and interactions with other materials.

If the color is different because the glaze was underfired, another firing at the correct temperature may change it.

But if the glaze chemistry or application is responsible, refiring may simply produce another version of the same result.

Can You Add More Glaze Before Refiring?

Sometimes, but this requires care.

After a glaze firing, the ceramic surface is no longer porous like bisque ware. New glaze may not adhere in the same way.

Potters sometimes apply additional compatible glaze or decorative materials to an already fired piece, but the method depends on the product.

If you’re considering this, follow the glaze manufacturer’s instructions and make sure the added material is suitable for another firing.

Can Refiring Make Pottery Worse?

Yes.

This is one of the most important things to understand before putting a disappointing piece back into the kiln.

Another firing can potentially cause:

• More glaze movement
• Glaze running
• Changes in color
• Loss of surface texture
• Additional cracking
• Warping
• Overfiring
• Damage to the kiln shelf

A piece that looks imperfect after its first firing isn’t automatically a good candidate for refiring.

Should You Refire at a Higher Temperature?

Don’t assume that a higher temperature will fix the problem.

The correct firing temperature depends on the clay and glaze.

If a glaze is designed for a particular temperature range, firing substantially above that range can cause the glaze to become excessively fluid or produce other defects.

The clay also has its own firing limits.

Always check the manufacturer’s recommended firing range before changing the temperature.

What About Refiring at a Lower Temperature?

A lower-temperature firing may be appropriate for certain decorative materials or products specifically designed for lower-temperature firings.

However, lowering the temperature doesn’t automatically correct a glaze problem either.

The important question is what material are you firing and what result are you trying to achieve?

How Many Times Can You Refire Pottery?

There isn’t a universal number.

Some pieces can tolerate several firings, while others may develop problems after additional heatwork.

The number of firings matters less than the total heatwork and the compatibility of the materials.

Every firing adds another thermal cycle, so repeated firing should be intentional rather than simply experimental on an important piece.

What Should You Do Before Refiring?

Before putting the piece back into the kiln, ask:

1. What went wrong?
Identify the actual glaze defect rather than assuming it needs more heat.

2. Did the kiln reach the correct temperature?
Check the controller, firing record, and cones if you use them.

3. Is the glaze compatible with another firing?
Check the manufacturer’s instructions.

4. Is the glaze already too fluid?
If it has already run or moved significantly, another firing could make things worse.

5. Is the clay still within its firing range?
The clay body has a maximum recommended firing temperature.

6. Can you test the solution first?
If possible, experiment with a less important piece before risking valuable work.

When Should You Not Refire?

Refiring may be a poor choice when the pottery has serious structural damage, the glaze has already overfired, or you don’t know whether the materials can tolerate another firing.

It’s also not a good idea to keep firing a piece repeatedly without understanding the cause of the problem.

Sometimes the best lesson is to document what happened, identify the cause, and change the process on the next piece.

Final Thoughts

Yes, you can refire pottery when the glaze goes wrong — but refiring isn’t a universal fix.

It can make sense when a glaze is underfired or when a compatible decorative process requires another firing. But if the problem comes from excessive glaze thickness, contamination, incompatibility, overfiring, or glaze movement, another firing may make the result worse.

Before refiring, identify the problem, check the clay and glaze firing ranges, and consider what the second firing is actually expected to accomplish.

Sometimes the best solution is another firing. Sometimes it’s changing the glaze application or firing schedule on your next piece. Knowing the difference can save your pottery, your kiln shelves, and a lot of frustration.