Vince Pitelka on sun 25 apr 04
> Several people have noted that after using mortar, it's impossible to
> recycle your bricks for the next kiln. The wet stuff that comes in a can
> has cement in it, and makes your $3.00 bricks a "one time" proposition.
> If you make your own kiln mortar, without cement in it, you CAN clean
> the old bricks easily.
Paul -
Sorry to seem contrary tonight, but now I must be contrary again. Let's
keep things on track here. If there is a situation where mortar must be
used, then your advice is good. But for a normal downdraft or updraft kiln
with 9" IFB walls, there is no reason at all to mortar the bricks, except in
the floor of a car kiln. Mortaring the walls offers no advantage in such a
kiln, and considrable disadvantages.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
Paul Herman on sun 25 apr 04
Hi Vince,
Greetings from the sagebrush scrub.
No need to apologise for contrariness, it's one of your strong points.
Hoho!
You're right that I got a little off track. As for whether Earl should
mortar his kiln, I have no strong opinion. My point was that you can use
mortar that is easily removable. I do have a strong opinion to not use
cement mortars, unless it's in a place where it's truely needed.
I'm curious as to what the disadvantages of mortar are, from your point
of view.
Building my gas kiln, using a mix of old and new softbrick, I was glad
to use mortar in the whole structure. I can see that with all new
materials and a nice straight foundation, dry stacking might be best.
What about a sprung or catenary arch, would you normally dry stack it?
best wishes,
Paul Herman
Great Basin Pottery
Doyle, California US
http://www.greatbasinpottery.com/
----------
>From: Vince Pitelka
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Re: Stak-O-Brix kiln - To mortar or not?
>Date: Sun, Apr 25, 2004, 8:15 PM
>
>
> Paul -
> Sorry to seem contrary tonight, but now I must be contrary again. Let's
> keep things on track here. If there is a situation where mortar must be
> used, then your advice is good. But for a normal downdraft or updraft kiln
> with 9" IFB walls, there is no reason at all to mortar the bricks, except in
> the floor of a car kiln. Mortaring the walls offers no advantage in such a
> kiln, and considrable disadvantages.
> Best wishes -
> - Vince
Paul wrote:
> Several people have noted that after using mortar, it's impossible to
> recycle your bricks for the next kiln. The wet stuff that comes in a can
> has cement in it, and makes your $3.00 bricks a "one time" proposition.
> If you make your own kiln mortar, without cement in it, you CAN clean
> the old bricks easily.
Vince Pitelka on mon 26 apr 04
Paul -
You bring up some very good points. When building with used brick, where
there is some discrepancy in size, mortaring is usually necessary, and I
certainly agree that a non-setting fireclay/fine sand or fireclay/fine grog
mortar is the best choice for that.
With new materials and a good flat foundation, there is no need to use
mortar, so the kiln assembles much faster. Years later, when the potter
changes her/his mind about the design, or sleeps through the night and wakes
up to cone 16 and a good meltdown, it is a simple matter to disassemble some
or all of the kiln for modifications or repairs.
And whatever mortar you use, it is still a considerable amount of work
cleaning it off the bricks, especially if the kiln has survived years of
high firings.
I would never mortar any kind of arch, because it is inevitable that the
bricks will shift a little with time, and then the mortar materials start
sifting down on the wares. With a mortarless arch, whether IFB or hard
brick, caternary arch or sprung arch, you get a lot less junk sifting down
on the wares.
Amazing what those Gothic cathedral-builders could accomplish with
dry-stacked stone.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/
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