Glaze Committee

The Glaze Committee's mission is to keep the glazes and decorating materials in good shape and ample supply and to make sure that club members and students who use these materials are kept informed of all developments.

Welcome to the committee and thank you for your participation.

Committee Responsibilities

Read at least first 3 pages of the booklet called "Glaze Safety"
Wipe down glazing table, glaze dollies, glaze shelving, and outside of glaze buckets as needed.
Straighten up glazing area as needed and keep the underglazes, slips, overglazes, and commercial glazes in their designated areas.
Order supplies for mixing glazes as needed--orders are placed by the chair(s). Committee members should notify the chair if a need is noticed.
Keep an ample supply of bisqued test tiles on hand for use by the committee. Please make some test tiles if they run low.
Keep glaze tiles current and representative of existing firing conditions.
Be sure that labels on glaze buckets are legible and indicate any problems with running and possible health concerns. When a new glazze is made please label with the date made.
Look for new glaze recipes.
Periodically stir the glazes, especially those that are infrequently used.

How to Mix a Glaze

Find recipe in blue glaze recipe book. See if the ingredients are available. If they are not - contact glaze chairperson.
Find 2 clean 5 gallon buckets and a clean lid. There are various size buckets so make sure that 5 gallon buckets are used. Use small buckets for 1000g trail, and use large buckets for all others. Plug the scale in, turn it on and tare with container on top. You are ready to weigh ingredients.
Before opening or handling any ingredients, put on a mask and gloves. Do not put your health at risk.
Get the needed ingredients. The glaze materials are in the sink room, roughly in alphabetical order. Flint and Silica are considered the same (Silica is 325 mest). Colorants (oxides, stains, etc.) are on the top shelves. If there is not enough glaze material or you can't find it, check the northwest wall of the basement. Measure the ingredients and add them to the bucket. Record the amount measured on a pad. Use 1000 gram increments for large amounts. Brush out the scale tray with a brush nto the bucket after each ingredient. Whisk the dry ingredients together.
This is a good stopping point if you do not have enough time to finish the glaze. Continuing on, add approximately a quarter bucket of hot water slowly to the dry ingredients and use the drill to mix it thoroughly. Adjust the volume of water until it is less than half the bucket
Sieve the new glaze through an 80 mesh screen into the second clean bucket, rinsing the initial bucket with hot water and through the mesh screen. Again sieve this glaze through the 80 mesh screen into the first bucket, using small quantities of water to rinse materials out of second bucket. There is a spatula kept with the sieve for scrapping out the glaze. Note: It is easy to add too much water. After two screenings the glaze should have the consistency of light cream. Add water if necessary.
Place lid on bucket and label both lid and bucket with the name and number of the glaze. Put "testing" and date the glaze was made on the lid label.
Leave glaze to meld in the sink room and come back in a day or so to make the white and red test tiles.
Be sure and clean the drill bit, extra bucket etc. in the waste water bucket the rinsing in the sink, and put materials and equipment back where they belong.
A day later, stir glaze and check consistency. The glaze level is usually 2/3 to 3/4 of the5 gallon bucket. Water frequently needs to added at this point because the glaze becomes thicker when left to sit overnight after the initial making of it. Label a red clay test tile and a white clay test tile with the number of the glaze made plus the date (2/17/10) with the underglaze pencil (hanging cabinet). Dip both tiles to within a quarter of the bottom, hold for 4 seconds. Let dry, and then dip half the tile again for 4 seconds. Put them in the cabinet to be fired.
Place the bucket in the corner by the door. It will stay there until you check the fired test tile.

Follow Up

Check the outcome of the test tile firing. If the glaze looks as it should, stir the bucket and combine it with the current bucket. Wash the now empty bucket and put it away. Discard the old test tile and replace it with the new one.

If the test tile does not look right, check your recipe sheet with the original in the book. Check with the Firing Committee for any misfires and consult with other members of the committee. You may need to remove water if the glaze is too thin, or add water if the glaze is too thick.