David Hendley on tue 5 jun 01
This whole 'arch made with straight bricks' question started out
concerning hard bricks. Now it's transmuted into making arch shapes
with insulating fire bricks.
This is reasonably doable.
If you have a table saw, it's pretty easy. Just install an old worn-out
blade backwards on your saw mandrel, and set the blade angle by
trial and error. You'll get it after a few test cuts. Once the blade is
set, the bricks can be run through the saw as fast as you can pick
them up and feed them through. To do it right requires a cut on each
side, and your bricks will make a 100% accurate arch.
This operation is, as you would expect, very dusty, so don't even think
about doing it unless your saw is outside and you have a good-quality
good-fitting dust mask.
If you don't have a saw, you can make arch shapes by making a jig
to set a brick in and then removing material with a rubbing stone.
Years ago, I set a straight hard brick on each side of an IFB, and
put a 9"long piece inch quarter-inch key stock under one edge of
the IFB. I then ground down the IFB until it was flush with the
hard bricks. This made fine #1 arch bricks.
This will take 3 or 4 minutes per brick, definitely not worth any
savings of buying straight bricks over arch bricks, but well worth
the time in certain situations. In my case, I bought a pallet of new
bricks for $1 a box (hey, it was the 70's), so I was happy to spend
a day shaping bricks to save hundreds of dollars.
There is no truth to the assertion that bricks made in this way will
sift particles down into the kiln. All IFBs are cut and sanded to
exact size. It's either done at the brick factory or you do it yourself.
As a funny addendum, in the 70's, I also built a kiln entirely out of
#1 arch bricks. Again, it was a deal too good to refuse, new bricks
for 5 cents each. I stacked 2 bricks together to make a 'semi-rectangle'
9" X 4 1/2" X ~ 4 3/4", as my basic building unit. What a relief to
finally get to the arch and use the bricks for their intended purpose.
The kiln lasted for years and years, and was finally unstacked when
I moved. Still have that big pile of arch bricks.
David Hendley
Maydelle, Texas
hendley@tyler.net
http://www.farmpots.com
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