Bob Hamm on tue 26 sep 00
Jonathan wrote
> These items will always have a potential to leak because of a few things.
>
> 1. Poorly applied glaze on the interior
> 2. Poor choice of glaze for the interior.
> 3. Higly viscous nature of liquid paraffin and lamp oils.
I agree with these statements by Jonathan. I would also add a fourth factor;
an improperly fired glaze can have the defects of a bad glaze. We also have
made more of these lamps then I want to count and the only ones that were
returned were because of incomplete glaze coverage on the inside. They were
all from one batch. A bad day glazing I guess. We had sealed them, but found
out the sealer did not work over the raw clay, and probably did not have any
effect over the glaze. Another knock against sealers. Like trying to repair
a hole in a dam with a coat of paint.
> Use a glaze that is a durable, well balanced hard glossy glaze and you oil
> lamps won't leak. The glaze should have no crazing and fit the body
> perfectly. Don't use matt glazes to line oil lamps.
The glazes I use now are satin matt to gloss fired to cone 6, with no lamps
returned because of leakage. I think the important point that Jonathan makes
is that the glaze must be sound and I would also avoid a very matt glaze.
Because the damage from leakage could be so serious, I tend to go for
overkill to deal with any unseen flaws in the materials and/or process. To
protect against possible oil sweating, I glaze the pot inside and out, and
then glue small bisqued clay buttons onto the glaze using white glue. This
provides feet to support the pot during the glaze firing. Should there be a
flaw and the pot sweats, the space these feet create will allow air to
circulate and the oil to evaporate. It works great and the buttons look like
they are an original part of the body, not an after glaze add on.
> Take some responsibility for glazing the ware correctly with a correct
> glaze and eliminate using what ever these aftermarket liners are and make
> better ware!
I agree and watch the firing.
Bob Hamm
Super Mud Works
Kelowna B.C. Canada
Phone (250) 765-8876
Email bobhamm@look.ca
Veena Raghavan on wed 27 sep 00
Message text written by Ceramic Arts Discussion List
> To
protect against possible oil sweating, I glaze the pot inside and out, and
then glue small bisqued clay buttons onto the glaze using white glue. This
provides feet to support the pot during the glaze firing. Should there be a
flaw and the pot sweats, the space these feet create will allow air to
circulate and the oil to evaporate. It works great and the buttons look
like
they are an original part of the body, not an after glaze add on.<
Hi Bob,
What a neat idea! I had stopped making oil lamps, because of the
danger of leakage. Now, I will try them again.
Thanks for sharing.
Veena
Veena Raghavan
75124.2520@compuserve.com
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