dahl

[josie]

does anyone know the coe of dahl glass?

[Bert Weiss]

Dalles are made for epoxy or concrete cast glass windows. They are not formulated for fusing. I have purchased dalles from Blenko and cast with them, but only using a single color that I bought in a single purchase. Remember that glass made in the morning may not be compatible with glass from the same furnace in the afternoon. Many colors from Blenko turn really awful colors when heated to casting temperatures. Blues are good though.

Your question about COE shows a fundamental lack of understanding of compatibility. There are other factors that make glasses compatible or incompatible, namely viscosity characteristics. PPG Starphire and Bullseye fusing compatible glasses both come referred to as COE 90, but are most definitely not compatible. The glass chemist, designing compatible glass batch formulas, will balance expansion with viscosity to make glasses that fit together.

Bullseye and System 96 both make glasses similar to dalles that they call billets, that are made for casting with other compatible glasses.

[josie]

Thanks Bert, i see i had this spelled incorrectly.
i am using one block with only itself. i am making a trial disk. i should have phrased my question more clearly.
if i have a firing schedule for say 90 coe would the blenko dalle take longer or less long?
i have it in the kiln right now and will know later today.
thx

[Bert Weiss]

Thanks Bert, i see i had this spelled incorrectly.
i am using one block with only itself. i am making a trial disk. i should have phrased my question more clearly.
if i have a firing schedule for say 90 coe would the blenko dalle take longer or less long?
i have it in the kiln right now and will know later today.
thx

It should pretty much match firing schedules.