How to achieve consistency with brushing glazes?

Strategic Glazing Q&A

This video clip is from a live Q&A session about my free Strategic Glazing class. Watch the video above or read the text version below to learn about consistency with brushing glazes.

Ideal consistency with a brushing glaze

Question: “Brush on glazes are less consistent in my experience. How do we know the ideal consistency with a brush on glaze?”

Brushing glaze is always going to be less consistent than other application methods because there’s just so much variation involved. Things like:

• The size and type of brush you’re using

• The length of your brush stroke

• How much glaze you get on your brush

• How many coats you apply

• How much overlap you get between brush strokes

These all affect the outcome. That variation makes brushing a more inconsistent method overall. But that doesn’t mean it can’t be done well—with practice and the right technique, you can get really nice results.

Glazes That Work Well for Brushing

If you’re going to brush, you want a glaze that doesn’t dry instantly when it touches the bisque. You want something that allows for nice, smooth brush strokes, so you can get even, easy coats on your piece.

When a glaze dries really quickly, your brush sticks to the bisque and you end up with lots of small brush strokes, which can make them visible on your piece. That’s not usually ideal, unless you’re intentionally going for a textured look, in which case you’re not so worried about them blending together.

I have found that flocculating a glaze with Epsom salts helps it to dry more slowly. Adding CMC gum solution is another option to improve brushability.

Choose the Right Brush

One helpful tip is to use as large of a brush as you can, based on the size of your piece or the area you’re glazing.

A nice, floppy brush that holds a lot of glaze will let you apply the glaze in long, even strokes, which is key to consistency.

If you use a small, stiff-bristled brush, you’ll end up painting stroke after stroke after stroke—and that leads to uneven coverage. A lot of glazes will highlight that unevenness, especially if the glaze changes color or texture with thickness.

When you’re overlapping strokes in some areas and only getting one layer in others, that will sometimes show. So a larger brush and a longer brush stroke will help give you a smoother, more consistent coat.

When to Use Brushing

While brushing isn’t the fastest, easiest or most consistent option, it definitely has its place.

For example, if you have a piece that’s difficult to dip, brushing (or spraying) might be more ideal. Or maybe you want different glazes on different parts of the piece—like a different glaze on the handle of a mug—so brushing that area makes more sense.

In those cases, brushing is the best choice. You just want to make sure you’re setting yourself up for success with the right brush, technique and glaze consistency.

Specific Gravity for Brushing

Question: “Is there a different specific gravity or viscosity to aim for if you want to brush rather than dip the glaze?”

And yes—there often is.

Specific gravity refers to the ratio of solid particles to water in your glaze. A higher specific gravity means less water in your glaze.

When you’re brushing, you want to have less water and more glaze particles in each stroke. That’s because when you dip your brush into the glaze, it absorbs water into the bristles and carries glaze particles along with it.

If the glaze is too watery, each brush stroke will leave behind a very thin layer of glaze, and you’ll have to do multiple coats to get good coverage. That means your bisque absorbs a lot of water, and once it gets too wet, the glaze may not stick properly.

So for brushing, you usually want to aim for a higher specific gravity than you would for dipping. This will also make the glaze thicker – higher viscosity – which is ideal for brushing.

Specific Gravity Ranges:

Ideal specific gravity very much depends on each glaze and many other factors. But here is generally what I have found works for many glazes.

• Dipping: Specific gravity around 1.45–1.50

• Brushing: Specific gravity around 1.50–1.60

A higher specific gravity for brushing helps ensure each stroke applies a good amount of glaze, without needing endless layers. That way, your bisque doesn’t get too wet and your glaze adheres better.

Summary

If you’re brushing glaze and want better consistency:

• Use a soft brush and the largest size that fits your piece

• Aim for long, smooth strokes instead of short, choppy ones

• Make sure your glaze doesn’t dry too fast—flocculate if needed

• Use a glaze with a higher specific gravity (1.50–1.60) to get more coverage per stroke

• Try to keep your bisque from getting overly wet by minimizing the number of coats needed

Brushing can be a really effective method, especially for touch-ups, detail areas, or pieces that can’t be dipped. With the right approach, it can produce beautiful, even results.

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