Tip #56: Tips on Resists (Wax, Latex, Melted Wax)
Using wax resist for even drying: It is often helpful to slow down the drying of one part of a piece while the rest catches up. For example, on the rims of plates, or where handles are attached to mugs. Brushing wax resist on these areas is a great solution. The wax slows drying in the areas where it is applied, and burns off in the bisque firing!
Did you know that we now carry Black Wax Resist? This is great for painting on lines (with a slip-trailer works great!) It creates a wax separation which makes it easy to fill areas with glaze. When fired, the wax leaves a black line behind, separating the colors.
Some people think that waxing the bottom edges of a pot helps keep the glaze from running off the pot. However, the wax burns off way before the glaze melts, so this unfortunately doesn't help. The only purpose of the wax is to make it easier for you to wipe the glaze off. It does help to have an undercut or small break in the surface toward the bottom of the piece. This break will help stop glaze at that point. (But don't depend on it too much. Runny or too thick glaze will still run right over.)
Dip your brush in soapy water or fabric softener before using wax resist, and the brush will be easier to clean.
People having trouble applying wax resist often are using it too thick. Try taking some into a separate container and thinning it with water. It will dry faster and may work better for you.
Once you use a brush for wax resist, don't use it for anything else. You might want to paint the ends of all your wax resist brushes a certain color.
When waxing lids, add alumina to the wax resist before brushing on. This keeps the lid from sticking. (Note, This works great on bisque. But if you happen to be refiring a high fired, very vitrified porcelain or stoneware piece, just apply alumina and water to the rim. The vitrified clay is not porous enough for the wax to penetrate, and the wax sometimes causes runs.)
One easy way to brush an even line of wax on the bottom of a pot is with a good banding wheel, or your pottery wheel. The trick is getting the piece centered, then the rest is easy. We have a variety of tools to help you recenter your pots quickly, such as the Giffin Grip, a foam trimming bat, or the BatGrabber. (The last 2 are on the Bat page.)
Another great way to cover the bottom of a pot quickly and evenly is to use those cheap "sponges on a stick" that are used for painting.
Resist can be used to create an even line between an inner and outer glaze, such as on a bowl.
Latex resist has a few advantages over wax resist. If you make a mistake, it can be peeled off of most surfaces. In fact, the way that latex resist forms a rubber film and can be peeled off is what makes it interesting. You can cover areas that you have already designed, glaze around them, and peel up the rubber latex to continue decorating beneath. We sell "Mask-n-Peel" latex resist. The biggest drawback of latex resists is that they clog your brush easily, but water based latex's clean much easier than oil based. Some people swear by dipping their brushes in Murphy's Oil Soap prior to use.
Hot wax is also sometimes used, but it can be dangerous due to the risk of fire and fumes. Paraffin wax is melted in an electric skillet, and the pieces are dipped in. This makes a very even line at the bottom. If using this technique make sure you keep the temperature low, and a fire extinguisher nearby just in case. If the wax smokes it is too hot.
Crayons can be rubbed over a surface to create a wax resist pattern. Sometimes the pigments in crayons will burn away and sometimes they will be left behind.
Shellac can also be used as a resist. One interesting technique is to paint on a pattern, then use a wet sponge to sponge away the clay that isn't covered by the shellac.
And a great tip came from a teacher. It is very difficult in a school situation to keep the wax brushes separated from the glaze brushes. And it is also very difficult to get students to adequately clean the glaze off the bottoms of their pieces. So she doesn't use wax at all. She created clay "pebbles" and discs, which she has the students hot glue to the bottom of the pieces after sponging the glaze off the bottoms. If the pieces run, the glaze is much less likely to reach the kiln shelves.
A sprayer without a compressor?
Have you seen the new Paintec Sprayers? You pump the handle to create air pressure, then spray. This is a great way to experiment with glaze spraying before investing in a lot of equipment. This product has had very favorable review, and the price is great!