How to use a hydrometer
A hydrometer is a tool used to measure the specific gravity of a glaze, which will tell you how thick the glaze is.
– Thoroughly stir the glaze
– Put exactly 1,000 milliliters of the glaze into the beaker labeled “Hydrometer Testing”
– Wet the hydrometer
– Carefully lower the wet hydrometer into the beaker with the glaze in it
– Wait at least 15 seconds for the hydrometer to naturally settle into the glaze
– Gently tap the side of the beaker a few times to make sure hydrometer completely settles
REMEMBER: Glazes will have different hydrometer readings. Here is the list of approximate measurements that our glazes should read on our hydrometer:
| Liz Kraus Shino | 50 |
| Rutile Blue | 50 |
| Rutile Green | 49.5 |
| Steve’s Copper Red | 52 |
| Temple’s Persimmon | 46 |
| Jeff’s Long Beach Blue | 53 |
| IUS Celadon | 48 |
| Monica’s Seafoam | 49 |
| Iron Saturate | 48 |
| Missouri Straw | 32 |
| Mackenzie White | 50 |
| Steven Hill Clear | 49 |
| Cushing Satin Black | 52.5 |
| Horsley’s Satin Matte White | 50 |
– When testing, if the number on the hydrometer is higher than listed above, add a little water and repeat the testing process until the hydrometer reads the correct number.
– If the number is lower than listed above, make a note on the bucket to have someone screen some water off the top of the liquid amount. (This of course has to be done AFTER the glaze has settled – usually after a day or so has gone by without anyone stirring the glaze) After screening some water off, then repeat the testing process until the hydrometer reads the proper number.
Here’s a Ceramics Arts Daily article on how to make your own hydrometer: http://ceramicartsdaily.org/clay-tools/making-clay-tools/how-to-make-a-floating-stick-hydrometer-for-the-cost-of-a-milkshake/