Monthly Tech-Tip | No tracking! No ads! |
Description: High calcium borosilicate frit
Oxide | Analysis | Formula | |
---|---|---|---|
Al2O3 | 10.25% | 0.33 | |
SiO2 | 57.50% | 3.18 | |
Na2O | 3.25% | 0.17 | |
K2O | 3.25% | 0.11 | |
CaO | 11.25% | 0.67 | |
MgO | 0.40% | 0.03 | |
BaO | 0.50% | 0.01 | |
B2O3 | 13.50% | 0.65 | |
Oxide Weight | 332.29 | ||
Formula Weight | 332.29 |
These sixteen GBMF test balls have melted down onto a slab of grogged clay. Kiln fired at 108F/hr for the last 100 degrees F and held for 15 minutes. This demonstrates the comparison value of this test and how various frits compare in their melting character.
These are higher temperature frits. 10 gram balls were melted on to this tile.
16 GBMF tests on a slab of grogged clay. Kiln fired at 108F/hr for last 100 degrees F and held for 15 minutes.
These were 10g balls melted using our GBMF test, the tile they are being fired on is a grogged stoneware clay. A few of the more interesting ones here are frit 3470 lead zinc, 3185 super high boron, CC257 high barium, FR003 high alkali and F49 and FR001 opacifieds. Notice how early and vigorously some are melting. But notice 557 and 556, they aren’t doing anything - that is not by accident. These are fast-fire frits, they are designed to melt later and more quickly. This is only 1700F, since no one fires this low it makes sense that if a glaze has not started melting it will be able to pass escaping gases of decomposition. This avoids the bubbles and surface defects these cause, as 3185, CC257 and 3470 are already demonstrating. What about FR002, FR002 and 3565, they are melting and look fine? They have higher surface tension and much less contact with the body generating the gases.
Typecodes |
Frit
A frit is the powdered form a man-made glass. Frits are premelted, then ground to a glass. They have tightly controlled chemistries, they are available for glazes of all types. |
---|
Co-efficient of Linear Expansion | 71 |
---|---|
Frit Melting Range (C) | 980-1030C |
By Tony Hansen Follow me on |
Buy me a coffee and we can talk