- CMC Gum (Carboxymethyl Cellulose) Powder – Ceramic Grade Gum for Glazes
- Makes Ceramic Glazes Brushable – Slows Drying time and allows ceramic glazes to be brushed smoothly and evenly without drag or chattering.
- Renews Old Dried out Glazes – Easily make your own brushing medium or gum solution to reconstitute dried out glazes.
- Binds Glazes – Additive Prevents glazes from cracking upon drying on bisque of greenware. Binds Underglazes so won’t smear when applying clear overcoat.
- Improves Troublesome Dipping Glazes – Small addition (.25-.5%) of CMC gum to dippable ceramic glazes improves suspension and binds glaze to bisque.
As a potter or ceramicist glazing (and then firing) is the make or break it step of the pottery process. It’s important for serious potters and hobbyists to have a full glazing tool kit to make this step successful. Ceramic grade CMC Gum powder is a useful glaze additive to make glazes perform better. CMC Gum is a natural gum substance derived from wood fibers and when dissolved in water creates a gelatin like gum substance. When added to ceramic glazes it acts as a binder or glue that slows the drying process and allows for smooth brushing. The gum also binds the glaze to the surface of the greenware or bisque ceramic. CMC gum is used in primarily 3 glazing application.
Brushing Aid for Glazes: Dry CMC gum is blended into dry glaze powder at 1-1.25 weight percent. Water is then added and vigorously mixed. After 20-30 minutes gum will have fully dissolved into the glaze and is ready to be brush applied.
Reconstituting Dried our Brushable Glazes: A gum solution is prepared by adding dry gum powder (250 grams gum powder to 2 gallons warm water) slowly into a container of warm water while the water is being vigorously mixed. Allow the mixture to sit 1-2 hours and the gum will dissolve and create a jelly like liquid. This gum solution is then added to dried out glazes to reconstitute and turn them back into a smooth creamy brushing consistency.
Suspender/Binder for Dippable Glazes: Dry CMC gum is blended into dry glaze powder at .25-.75 weight percent. Water is then added and vigorously mixed. After 20-30 minutes gum will have fully dissolved into the glaze and is ready to be dip applied. Dipping glazes with gum added will take longer to dry than glazes without CMC. The CMC acts as a binder and will harden the dried glaze and bind it to the bisque or greenware glaze surface and is useful with glazes that tend to crack on drying.