iandol on fri 8 dec 00
It may not be common knowledge but many clays contain small proportions =
of Fluorite as residual minerals. When fired to a high temperature, this =
material, which is regarded as a flux in ceramic terms, decomposes. The =
fluorine which is discharged mixes with water vapour to form =
Hydrofluoric acid. It is this which etches the glass. I have =
concentrated sulphuric acid which is stored in a glass container. I do =
no believe the supplier would pack it in glass if it dissolve that =
material.
Now I am sure others will confirm that Hydrofluoric acid is a serious =
health hazard.
Ivor Lewis. Redhill, South Australia
Jennifer F Boyer on fri 8 dec 00
I remember a room in which a friend was running an electric
kiln. The windows were smokey from being etched by the kiln fumes!!
Jennifer, shuddering
iandol wrote:
>
> It may not be common knowledge but many clays contain small proportions =
> of Fluorite as residual minerals. When fired to a high temperature, this =
> material, which is regarded as a flux in ceramic terms, decomposes. The =
> fluorine which is discharged mixes with water vapour to form =
> Hydrofluoric acid. It is this which etches the glass. I have =
> concentrated sulphuric acid which is stored in a glass container. I do =
> no believe the supplier would pack it in glass if it dissolve that =
> material.
>
> Now I am sure others will confirm that Hydrofluoric acid is a serious =
> health hazard.
>
> Ivor Lewis. Redhill, South Australia
>
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Jennifer Boyer mailto:jboyer@adelphia.net
Thistle Hill Pottery
95 Powder Horn Glen Rd
Montpelier, VT 05602 USA
802-223-8926
http://www.thistlehillpottery.com/
Check out this searchable sites about web hoaxes:
http://urbanlegends.about.com/science/urbanlegends/library/blhoax.htm
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