Glaze is a liquid that comes in nearly any color and it’s used to waterproof, decorate and give pottery a smooth, glass-like surface once it has been fired once.
The most common way to glaze pottery is by completely dipping the piece in a five-gallon bucket of dipping glaze. However, for most precise applications and to achieve specific results, it’s possible to pour it directly on the pieces or apply it with the help of brushes or even a sprayer.
Glaze comes in a variety of presentations depending on how you would like to apply it to the pieces. It usually comes as a powder that you will have to mix with water and sift very well before it’s ready to be used. Once mixed, the liquid glaze can be used multiple times and can be stored at room temperature for weeks. As long as you stir it and make sure it’s well mixed every time you use it, you’re good to go.
It is possible to apply multiple layers of glaze of different colors on a single piece. However, they all have to be applied before the pieces are fired. Once the glazed items go into the kiln, there’s no going back; you won’t be able to remove the glaze or glaze them again.
Wax Resist and Masking Tape
Wax resist is an oil-based compound used to prevent glaze from adhering to the clay. Wax is applied (usually with the help of a sponge or a bush) on those parts you don’t want covered in glaze. It’s usually applied on the bottom of round pieces such as mugs and vases to prevent glaze to fuse to the kiln shelves when fired or simply to play with different decoration materials or other glazing techniques to create different patterns.
Once wax is applied, you’ll need to dry it for a couple of hours before you can put glaze on them. Also, it’s important you know that once wax is applied on the clay, you won’t be able to remove it unless you sand the clay off using fine-grit sandpaper. This isn’t ideal as it’s not easy, takes time, requires further supplies and might damage the piece. So, we advise you to be as precise as possible when applying wax.
Using masking tape is another way to keep glaze away from certain areas. One of the advantages of using tape instead of wax is that this way you can create straight lines quicker and easier than if you were to apply wax with a brush. Also, it makes the decorating process much faster as you don’t have to wait for the wax to dry, you can simply put the tape on and apply the glaze immediately. Glaze dries very quickly so you'll be able to peel the tape off a few seconds after the glaze is applied and the items will be ready for another layer of glaze if needed or to go straight into the kiln.
Where to buy glaze
It depends on the quantity as well as the type of glaze you need.
Glaze is usually available in any art supply store as well as online. Just like clay, there are many different types of glaze. Basically every manufacturer or brand will have their very own mix that you might like better than others. They all have different colors, textures and firing temperatures.
When you buy glaze for the very first time, it’s very difficult to guess how the liquid will look once it’s fired. But don’t worry, most shops have samples of how the different glazes look like when fired so you can check their color and texture before you buy them.
If you are buying in large quantities and want to get better prices, we advise you to go to a local pottery supply store as most of them make their very own glaze rather than selling branded ones, which means you’ll spend less while supporting a local business.
You can also check out our range of glazes and underglazes at Soul Ceramics.
How To Glaze Pottery
Glazing pottery is super simple.
Step 1: Bisque-fire your piece
Clay needs to be fired before it’s glazed. This process is known as biscuit or bisque firing and it refers to the very first time the pieces go into the kiln. Potters usually bisque-fire pottery at different temperatures, but the usual process takes several hours and the kiln tends to slowly reach temperatures of around 1000° C. Once this process is finished and the ceramics cool down, they’ll be ready to be glazed.
Keep in mind that bisque-firing pottery is not enough for clay to reach maturity. The actual temperature needed to achieve maturity changes depending on the specific kind of clay and therefore, you will most likely have to fire your items several times at different temperatures before they’re ready to be used, especially if you are making tableware.
Read our post about pottery clay if you want to know more about the subject.
Step 2: Prepare your piece for glazing
This is the stage where you wax or put the masking tapes on the parts you don’t want to glaze. As mentioned before, pay special attention to the bottom of the items and think about how you'll place them in the kiln so the glaze doesn’t come into contact with the kiln shelf to avoid the pieces sticking to it.
Step 3: Glaze your piece
When the piece is waxed, it’ll be ready for the glaze. If you are going to dip it in a big bucket of glaze, we advise you to get dipping tongs as it makes the process easier. This way you’ll be able to glaze them in a quick, single motion. It only takes a few seconds… it goes in and right out.
If you’d rather use a brush to glaze your piece, the process is not much different from painting.
Step 4: Fire your piece
The exact temperature and firing process depends on the glaze and clay you’ll be working on. The most common firing process usually takes about 8 hours and it takes the pieces around 12 hours to cool down. After that you might need to fire them again if something didn’t go quite right or if you want to achieve other looks.
In most cases, the kiln will need to reach temperatures of about 2000° C very, very slowly. Therefore, you’ll need an electric kiln as other kinds of kilns usually reach those temperatures way too fast for glaze to fire properly.
Additional Glazing tips
Glazing is very much an inexact science. It’s best to try different techniques and ideas until you come up with a solution that suits you. Here are some additional tips that might help:
Ensure there are no resist spots on your pottery
In order to avoid unsightly spots, try to ensure that you keep lotions or oils away from your pottery. Any oil will repel the glaze, so it’s best to ensure your hands are thoroughly clean or wear gloves. Gloves are probably the best idea because even the natural oil from your skin can cause issues with glaze not adhering.
Ensure that your glaze is thoroughly mixed
Whatever technique you are using to apply your glaze, you have to make sure that you mix your glaze thoroughly. Use an electric drill with a mixer attached as a cheap and effective method and then put through a sieve to really smooth and remove any unwanted particles, then continue to mix. Mixing a glaze, even if it appears to be ready mixed, is a good habit as it ensures a nice even consistency.
Make a note of what you do for next time
Keep track of what works by making some notes as you go along. In that way you’ll know what glaze mixes worked well and what techniques had the best outcomes. You could even take a picture of finishes so you know what finish can be achieved.
Apply the glaze liberally
If you use a brush to apply a glaze you can encounter streaking. Just as you would when applying paint to a wall, if you don’t load your brush with enough glaze, the finish will be streaky. Ensure that your brush is well loaded and consistently reloaded with glaze to create a nicely glazed finish.
Remove glaze drips after the piece has dried
If you apply too much glaze to an area that has already been glazed, don’t be tempted to wipe it off. Excess glaze on your pottery is best-taken care of after the glaze is dry. If it’s still wet, you will inadvertently remove too much, and it will show.
Best electric kilns
Here at Soul Ceramics, we are experts in electric kilns. If you still don’t own one, no worries! Here’s a full guide that will help you decide which electric kiln is the best for you depending on the projects you’ll be working on as well as the space you’ll be working from.
Also, you can check our Ceramic Kilns page, see all the kilns available and learn all about them.
If you’re new to pottery making and need extra help with the materials or equipment needed, don’t hesitate to contact us and we’ll help you decide what’s best for you.
Good luck with your pottery projects!
Additional resources on pottery and glazing
- Why crazing happens and how to prevent it
- A guide to China painting
- How to make pottery at home
- How to use a slump mold for pottery
