Check For Correct Consistency of Clear Glaze
A viscosity cup measures the consistency of glaze or liquid. It is like a ladle and includes a plastic cup or scoop with a single hole on the end of a handle. The hole allows the glaze to flow out. The cup has a handle so that it can be dipped in the glaze.
Simply fill the cup with glaze and time how long it takes for the liquid to dispense through the hole. Our Hobby Colorobbia and Duncan Ceramics Clear Glazes will take about 19-24 seconds to dispense from full to empty. Note: not all clear glazes need to be the same consistency - please ask for guidance from your supplier or manufacturer.
Experience is the best guide to determine the consistency of glaze but unfortunately experience takes a while to develop. A viscosity cup will give added confidence to the novice glazer.
A viscosity cup is a device used to compare or measure the density of liquid. Glaze will usually arrive at “nearly” the recommended consistency. Concentrated or powdered glazes need to be mixed by following the manufacturer’s guidelines or recommendations. However, some glaze containers have no instructions on the labels.
Remember water is the thinnest ingredient in glaze. If there are lots of items to dip glaze or if the glaze itself is stored in a warm environment, then the water will evaporate leaving a thicker consistency of glaze. This evaporation often makes it difficult to calculate whether glaze is too thick - the effects of thickened glaze are only noticeable after an item is fired (and by then it is too late and a piece could get ruined).
(click on the image below to see a video created by Bisque Imports):
You will need a stopwatch or a watch with a second hand.
Click here to see more step-by-step guidance from Duncan Ceramics.
Click here to watch a video from Bisque Imports.
Please note the advice and recommendations given in this document are provided as an aid to novice glazers and firers. The notes given are not step-by-step instructions but are provided as “general” suggestions following years of glazing and firing experience. Country Love Crafts will not be held liable for any sub-standard results as a consequence of the guidelines given. However, please do contact us for advice if the desired results are not achieved.