I.Lewis on thu 18 nov 99
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Burt Cohen =3Cnorthfire=40bc.sympatico.ca=3E put forward the suggestion of =
using
Sodium silicate as a binder for the surface of refractory fibre.
Using one of the sodium silicates as a binder for a refractory concrete may
provide adequate when it becomes absorbed into the fabric of a cast =
structure to
create a thermally stable mixture, but it may not be satisfactory as a way =
of
sealing and securing loose refractory fibres of a kiln wall. I say this =
because
the melting point of Na2O,SiO2 is on the map at 1089C (1992F) and NaO2,2SiO2=
is
at 874C (1605F). Only experimentation would determine whether or not it =
might
form a stable, durable mixture with the fibre it attacked as it melted.
Another query which seems to have gone unanswered is the potential of =
household
thermal insulation bats as a kiln material. Again, stability tests would be
needed. These commercial products are said to be made from molten rock. I =
used a
high temperature fire resistant grade as backup in my own small fibre kiln. =
Its
maximum service temperature was given as 800C (1472F). I would not trust =
pink
bats and since the instructions suggest you should wear a mask when laying =
the
things in the ceiling, the dust from them will be a health hazard. Yes, I =
did
wear a mask when I put insulation in the roof of our house=21
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