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refractory expansion question

updated wed 1 sep 99


Tracy Dotson on tue 31 aug 99

Just got back from the kiln in Va. Loved it and got to fire it before I
left. Sweet kiln. They will call me when they unload it today to see how
the glazes came out. Now Expansion. On the small (Compared with industrial)
kilns I only am concerned with the first firing knowing that the car will
expand somewhat and get a better fit for future firings. The refractory
materials today are not as dimensionally contestant as they usto be. This
last construction had APgreen straights 2600 IFB,s that varied upto 3/16 in
length and 1/8 in thickness from the smallest to the largest. Yes, I know
that APgreen (industry best) was bought up by Harverson Warker a couple of
years ago and have been going down hill ever since. Even the #1 arch bricks
were 1/4 " shorter on the 9" and 4 1/2" than the straight bricks. Makes dry
stacking a bitch. Hard bricks have never been consistent with the dimensions
of IFBs so you kinda have to figure out which row on the floor and wall will
make up the largest dimension and just fill in the gaps as you go along with
Square, plum and level especially at the corners. I have always felt that
all of my brick placement is a whole lot looser than the industrial
installations and allow the kiln to settle in without expansion gaps. Hope
this helps. Back to making pots for a while. Tracy