I need help regarding Under glazes

[Caree J]

HI! I bought the Laguna Underglaze. I fired with BMX to cone 06. After that, I applied Laguna Underglaze silk to the bisque and did 3 coats of the flamingo to cone 5. That did not turn out, so did it again to cone 6. It looks like it never fired. It is chalky/white.  Please advise

 

[Kelly in AK]

Most underglazes will fire dry and chalky looking unless coated with a clear glaze. The sample tiles for Silk underglazes on Laguna’s website show one half coated with clear glaze and the other half unglazed.

[Hulk]

The color might matter.
The Axner site* indicates they've had good luck firing some of the colors to Cone 6.
Both Laguna and Axner otherwise indicate the Silky products are Cone 06. 

"Some Silky underglazes can be fired to cone 6 for similar results as shown below; we've had great results with SIL10, SIL44, SIL45, SIL47, SIL54, SIL55, SIL58, SIL60, SIL61, SIL67, SIL70, SIL71, SIL74, SIL76, SIL82, SIL84."'

Flamingo is SIL22?
Still, might try it with a clear glaze - test it with a clear glaze over the underglaze.

*Laguna and Axner merged some time ago. If I recall, Axner bought the Laguna company.

[neilestrick]

Most underglazes will remain matte and chalky unless they are covered with a clear glaze.  Typical underglazes do no melt out and go glossy like a glaze does. There are exceptions, like the Mayco Stroke 'n' Coat products, but they are more of a wide-firing-range glaze than an underglaze (although they can be used like an underglaze in many cases). Most underglazes are formulated for low fire work, but many will fire to cone 6 just fine, some colors will distort at cone 6, and some colors will burn out completely. If your pink glaze is now white, I think it's one of those that burns out, which is not entirely surprising since warm colors are often very sensitive to higher temps. First thing to do is to try it again on a fresh piece, and use a clear glaze. If it still burns out white then you need to find a different brand that has a pink you like. When you find one, look at that brands resources and see if it will work at cone 6. I know from experience that Speedball's pink will work at cone 6, however I don't love that color- it's a little too salmon. So I mix it 50/50 with white to get a good pink. Underglazes of the same brand can be mixed to get new colors, however you have to test fire them because the color you see before firing may not be the same after firing since different colorants have different strengths. An 80/20 blend of two colors may look perfect before firing, but after firing you actually need a 30/70 blend. I run a line blend when testing- 90/10, 80/20, 70/30....10/90 so I get the full range to select from.