Gayle Bair on wed 22 sep 99
Hi all,
A customer called me today with a leaking oil
lamp problem. This piece is about the size and
shape of a grapefruit, has a very small
hole for the wick. It is glazed inside but
heavily carved, lightly glazed on the
outside, no glaze on the bottom and was fired
to ^6.
The oil is apparently leaking from the bottom.
Is there something she can use to seal the bottom?
Since the oil has saturated the bottom I am assuming
it has to be something that will not need a clean
oil-free surface.
I think I have learned a valuable lesson. My next
oil lamps will be glazed on the bottom!
Thanks,
Gayle-enjoying what is probably the season's last
SUNNY day on Bainbridge Island WA
gaylebair@earthlink.net
Vicki Ferris on thu 23 sep 99
Hi Gayle,
Try sealing your lamps with an acrylic spray on the outside. It works for me.
Also
a friend mentioned Thompson's water seal but I haven't tried it yet.
Vicki from Cool, CA
Steve Dalton on thu 23 sep 99
Gayle,
Here's something...Axner sold (I'm not sure if they still do) a sealer used
inside of oil lamps.
The oil is leaking through the pores in the fired clay. I read about it in
I think either CM or
CT or even PMI. You might want to contact Howard down there and ask if the
piece
has to be free of oil.
Steve Dalton
----------
> From: Gayle Bair
> To: CLAYART@LSV.UKY.EDU
> Subject: Leaking oil lamp
> Date: Wed, 22 Sep 1999 14:17:52 EDT
>
>----------------------------Original message----------------------------
>Hi all,
>A customer called me today with a leaking oil
>lamp problem. This piece is about the size and
>shape of a grapefruit, has a very small
>hole for the wick. It is glazed inside but
>heavily carved, lightly glazed on the
>outside, no glaze on the bottom and was fired
>to ^6.
>The oil is apparently leaking from the bottom.
>Is there something she can use to seal the bottom?
>Since the oil has saturated the bottom I am assuming
>it has to be something that will not need a clean
>oil-free surface.
>I think I have learned a valuable lesson. My next
>oil lamps will be glazed on the bottom!
>Thanks,
>Gayle-enjoying what is probably the season's last
> SUNNY day on Bainbridge Island WA
>gaylebair@earthlink.net
Cindy Strnad, Earthen Vessels Pottery on thu 23 sep 99
Gayle,
Aftosa carries oil lamp sealer. I think you'll do better to just replace the
lady's lamp than to try and seal it at this point, though.
I've never had a problem with this--due, I'm told, to a lucky combination of
clay and glaze. Many glazes do allow oil through for one reason or another.
Something to do with their molecular structure. That's why Aftosa sells a
lamp sealer. If the oil is getting through one layer of glaze, I expect it
can make it through two as well. I recommend you check out the sealer, and
test before you sell.
Good luck.
Cindy Strnad
Earthen Vessels Pottery
Custer, SD
=?iso-8859-1?Q?Ren=E9?= Sprattling on thu 23 sep 99
Hi Gayle,
I remember reading some time back (maybe on Clayart) that oil molecules are
smaller than water molecules and can seep through clay even when water
can't. At C 6 Your clay is probably not vitrified enough to stop the fow
of these sneeky oil melcules. One way to fix this is to coat the inside of
the lamp with a marine varnish or similar type of sealant. Just pour a
small amount in, swish it around and pour it out. Then let it dry
thoroughly before refilling with oil. Glazing the bottom of future lamps
may not solve the problem if you have a less than perfect glaze fit, so you
may want to keep up the swishing.
>----------------------------Original message----------------------------
>Hi all,
>A customer called me today with a leaking oil
>lamp problem. This piece is about the size and
>shape of a grapefruit, has a very small
>hole for the wick. It is glazed inside but
>heavily carved, lightly glazed on the
>outside, no glaze on the bottom and was fired
>to ^6.
>The oil is apparently leaking from the bottom.
>Is there something she can use to seal the bottom?
>Since the oil has saturated the bottom I am assuming
>it has to be something that will not need a clean
>oil-free surface.
>I think I have learned a valuable lesson. My next
>oil lamps will be glazed on the bottom!
>Thanks,
>Gayle-enjoying what is probably the season's last
> SUNNY day on Bainbridge Island WA
>gaylebair@earthlink.net
Des Howard on thu 23 sep 99
Gayle
First & foremost your customer does not have a leaking oil lamp
problem, YOU have a leaking oil lamp problem.
Resolutions:
1. Refund money to customer immediately, along with apologies.
2. YOUR oil leak is occurring despite inside glaze, conclusion is glaze &
body
are not oil tight, so, glazing bottom of pot will be useless.
3. Do not sell any more items of this type until the glaze/ body problems
have been resolved.
The ethics of your problem attracted this one & only post from me,
the technical aspects I'll leave to the other Clayarters.
Des
Des & Jan Howard
Lue Pottery
LUE NSW 2850
Australia
Gayle Bair wrote:
> ----------------------------Original message----------------------------
> Hi all,
> A customer called me today with a leaking oil
> lamp problem. This piece is about the size and
> shape of a grapefruit, has a very small
> hole for the wick. It is glazed inside but
> heavily carved, lightly glazed on the
> outside, no glaze on the bottom and was fired
> to ^6.
> The oil is apparently leaking from the bottom.
> Is there something she can use to seal the bottom?
> Since the oil has saturated the bottom I am assuming
> it has to be something that will not need a clean
> oil-free surface.
> I think I have learned a valuable lesson. My next
> oil lamps will be glazed on the bottom!
> Thanks,
> Gayle-enjoying what is probably the season's last
> SUNNY day on Bainbridge Island WA
> gaylebair@earthlink.net
Gayle Bair on fri 24 sep 99
Dear Des,
The very first words out of my mouth was,
"I will be glad to refund your $."
I haven't even deposited her check!
It is my problem and never assumed anything
other than that! However the fact that she
purchased it makes it her possession, as she
loves it and wants to keep it also
makes it a problem for her!
I am sending this post through Clayart as you
didn't send your comments directly to me. Call
me anything you want but do not call me unethical!
I have received several technical posts
that suggesting the need to use a sealant.
Here are some of them:
..........................
I remember reading some time back (maybe on Clayart)
that oil molecules are
smaller than water molecules and can seep through
clay even when water
can't. At C 6 Your clay is probably not vitrified
enough to stop the flow
of these sneaky oil molecules. One way to fix this
is to coat the inside of
the lamp with a marine varnish or similar type of
sealant. Just pour a
small amount in, swish it around and pour it out.
Then let it dry
thoroughly before refilling with oil. Glazing the
bottom of future lamps
may not solve the problem if you have a less than
perfect glaze fit, so you
may want to keep up the swishing.
Try sealing your lamps with an acrylic spray
on the outside. It works for me.
Also a friend mentioned Thompson's water seal
but I haven't tried it yet.
I suspect you or customer will have to heat the
lamp base to boil off the
oil (slowly!), a convection oven would likely be
best (if the kiln isn't
to be used). Then with the oil all gone, you can
treat the pot (in an out)
with a high quality epoxy resin which is a thermosetting
type that will
subsequently not be affected by the lamp oil.
...................
I hope this clarifies the matter,
Gayle
gaylebair@earthlink.net
----------------------------Original message----------------------------
Gayle
First & foremost your customer does not have a leaking oil lamp
problem, YOU have a leaking oil lamp problem.
Resolutions:
1. Refund money to customer immediately, along with apologies.
2. YOUR oil leak is occurring despite inside glaze, conclusion is glaze &
body
are not oil tight, so, glazing bottom of pot will be useless.
3. Do not sell any more items of this type until the glaze/ body problems
have been resolved.
The ethics of your problem attracted this one & only post from me,
the technical aspects I'll leave to the other Clayarters.
Des
Des & Jan Howard
Lue Pottery
LUE NSW 2850
Australia
Gayle Bair wrote:
> ----------------------------Original message----------------------------
> Hi all,
> A customer called me today with a leaking oil
> lamp problem. This piece is about the size and
> shape of a grapefruit, has a very small
> hole for the wick. It is glazed inside but
> heavily carved, lightly glazed on the
> outside, no glaze on the bottom and was fired
> to ^6.
> The oil is apparently leaking from the bottom.
> Is there something she can use to seal the bottom?
> Since the oil has saturated the bottom I am assuming
> it has to be something that will not need a clean
> oil-free surface.
> I think I have learned a valuable lesson. My next
> oil lamps will be glazed on the bottom!
> Thanks,
> Gayle-enjoying what is probably the season's last
> SUNNY day on Bainbridge Island WA
> gaylebair@earthlink.net
Gavin Stairs on fri 24 sep 99
At 11:04 AM 9/23/99 -0400, you wrote:
>----------------------------Original message----------------------------
>Hi Gayle,
>
>I remember reading some time back (maybe on Clayart) that oil molecules are
>smaller than water molecules and can seep through clay even when water
>can't.
Not smaller: bigger. But water is strange stuff. It is polar, meaning it
is like a little magnet with north and south poles, only it not magnetic
but electric. So it has a negative side and a positive side; two little
knobs, actually, where the hydrogen sits nestled into the oxygen. This
polarity means that water tends to stick to other polar things, like the
edges of fired clay cracks. So water tends to clog up a very fine crack or
pore, while oil doesn't, since it is essentially non-polar. Inorganic, or
mineral, oil molecules are mostly covalently bonded carbon and hydrogen.
Organic oils have a little more polarity, and they will eventually dry and
fill cracks, but they will also do the same to wicks and such.
There are a number of penetrating, drying materials that will seal your
lamps. The commercial materials have already been mentioned. I rather
think that some drying oils would work as well, as well as some wood
sealants. Maybe acryilic medium. Even milk. What would work on a lamp
already saturated with lamp oil is another story. The oil tends to prevent
the polarizing attachment process referred to above in reference to water.
So not everything that will work on a dry pot will work on a used one. My
guess is that a drying oil would be the best bet. Thin some linseed or
tung oil in some petroleum spirits or turpentine, fill the lamp for a while
until some of the oil has seeped out, then dump out the oil and set it to
dry for a few days. No guarantees though. If you try this, please let me
know how it works out.
Gavin
Ruth Gill on fri 24 sep 99
Hi everyone, I just want to tell you that if you completely glaze the bottom
of the oil lamp inside AND out,and fire upside down on a glaze clean top
edge, it will help. You should also use a sealer. I used to use a good
concrete sealer, pour it in and let it sit over night. Oil will seep thru
anything, and it is your responsibility to make sure it is not a fire
hazard, at the very least. From Rikki in Berkeley, where not only did we
have no summer this year, we are not having any indian summer, either.
rikigil@cwnet.com
Tom Wirt on fri 24 sep 99
> Gayle Bair wrote:
>
> > ----------------------------Original message----------------------------
> > Hi all,
> > A customer called me today with a leaking oil
> > lamp problem. This piece is about the size and
> > shape of a grapefruit, has a very small
> > hole for the wick. It is glazed inside but
> > heavily carved, lightly glazed on the
> > outside, no glaze on the bottom and was fired
> > to ^6.
> > The oil is apparently leaking from the bottom.
> > Is there something she can use to seal the bottom?
> > Since the oil has saturated the bottom I am assuming
> > it has to be something that will not need a clean
> > oil-free surface.
I have rarely seen oil lamps fired at cone 6 that don't seep....even with
glaze inside. There must be something about the vitrification at cone 10
that produces a body that is tight enough to hold in the oil molecules which
are much smaller than water molecules.. Certainly I have not seen all cone
6 bodies, but probably a random sample of 10 or so....and every one of them
had the same problem. But the person with the ring on their shelf has
reason for concern.
Which all brings up a point....don't you test your own products in everyday
use. Don't you regularly bring pots from your production into your house?
This would have discovered the problem before it got very far outside.
Sorry, but dammit, your customer should not be your tester.
Tom Wirt
Lori Pierce on sat 25 sep 99
Tom, I think if the number of oil lamps I made were few, I'd take ten pounds
of the ^6-10 commercial body, that I fired to ^6, and add about 3% talc to
it and try to tighten it up that way...I would turn the talc into slurry and
wedge it in well and TEST. Lori in New Port Richey Fl.
-----Original Message-----
From: Tom Wirt
To: CLAYART@LSV.UKY.EDU
Date: Friday, September 24, 1999 10:45 AM
Subject: Re: Leaking oil lamp
>----------------------------Original message----------------------------
>> Gayle Bair wrote:
>>
>> > ----------------------------Original
message----------------------------
>> > Hi all,
>> > A customer called me today with a leaking oil
>> > lamp problem. This piece is about the size and
>> > shape of a grapefruit, has a very small
>> > hole for the wick. It is glazed inside but
>> > heavily carved, lightly glazed on the
>> > outside, no glaze on the bottom and was fired
>> > to ^6.
>> > The oil is apparently leaking from the bottom.
>> > Is there something she can use to seal the bottom?
>> > Since the oil has saturated the bottom I am assuming
>> > it has to be something that will not need a clean
>> > oil-free surface.
>
>
>I have rarely seen oil lamps fired at cone 6 that don't seep....even with
>glaze inside. There must be something about the vitrification at cone 10
>that produces a body that is tight enough to hold in the oil molecules
which
>are much smaller than water molecules.. Certainly I have not seen all cone
>6 bodies, but probably a random sample of 10 or so....and every one of them
>had the same problem. But the person with the ring on their shelf has
>reason for concern.
>
>Which all brings up a point....don't you test your own products in everyday
>use. Don't you regularly bring pots from your production into your house?
>This would have discovered the problem before it got very far outside.
>
>Sorry, but dammit, your customer should not be your tester.
>
>Tom Wirt
>
Ditmar/Gayle on sat 25 sep 99
------------------
Oil saturating the clay makes most of the repairs un-doable at this
point.........
so, if the customer can leave the lamp with you for a while, try refiring =
it.
Take the lamp to 1100 - 1200 degrees F. ( oxidation) and soak, to burn out =
the
oil completely, cool and then seal with method of your choice. That =
temperature
shouldn't do much to the glaze / look of the lamp.... use your judgement.
>From Alohaland, Ditmar.
PS I'd also check for hairline cracks too. They could also be the culprit.
Lynn Koning on sun 26 sep 99
I have to agree with Cindy. It's probably too late to seal this lamp, but be
sure to check out the lamp liner from Axner. With this you leave the inside
unglazed and then pour in the lamp liner and pour out the excess. Works
great. I've never had a lamp to leak oil at all.
Lynn in L.A. (lower Alabama)
Lynn Koning on sun 26 sep 99
just sent that last mail and realized I said Axner and not Aftosa. Sorry.
Cindy Strnad, Earthen Vessels Pottery on sun 26 sep 99
Ditmar,
I remember a while back there was a post on the list from a woman who fired
a bowl to clean the oil her son had gotten in it--changing oil or
something. The bowl exploded in the kiln and caused a lot of damage. I don't
think I'd risk it for the sake of one little oil lamp.
Cindy Strnad
Earthen Vessels Pottery
Custer, SD
Gerard Carriere on tue 28 sep 99
------------------
Leaky oil lamp
Hi. I make mini-oil lamps and found out that most of them leaked just
enough in spite of the cone 6 glossy glaze to make it smell and possibly
damage a table or shelf. I had started to make saucers to ensure the minute
leaking would not reach the shelf. A potter friend told me she has been
using regular varnish inside in order to seal the glaze because oil is so
penetrating that it tends to go through many glazes.
I would not use varnish inside an oil container used for cooking oil
although I have noticed the same problem in that case. I have been using a
saucer to partly solve this problem but would be interested in a more
satisfactory solution. G=E9rard in No=EBlville, Ontario
----------
=3E From: Gayle Bair =3Cgaylebair=40earthlink.net=3E
=3E To: CLAYART=40LSV.UKY.EDU
=3E Subject: Leaking oil lamp
=3E Date: 22 septembre, 1999 14:17
=3E
=3E ----------------------------Original message----------------------------
=3E Hi all,
=3E A customer called me today with a leaking oil
=3E lamp problem. This piece is about the size and
=3E shape of a grapefruit, has a very small
=3E hole for the wick. It is glazed inside but
=3E heavily carved, lightly glazed on the
=3E outside, no glaze on the bottom and was fired
=3E to =5E6.
=3E The oil is apparently leaking from the bottom.
=3E Is there something she can use to seal the bottom?
=3E Since the oil has saturated the bottom I am assuming
=3E it has to be something that will not need a clean
=3E oil-free surface.
=3E I think I have learned a valuable lesson. My next
=3E oil lamps will be glazed on the bottom=21
=3E Thanks,
=3E Gayle-enjoying what is probably the season's last
=3E SUNNY day on Bainbridge Island WA
=3E gaylebair=40earthlink.net
Cindy Strnad, Earthen Vessels Pottery on wed 29 sep 99
Gerard,
I think the problem must lie with the clay body. I reached this conclusion
because my oil lamps do not leak, despite the fact that I've had many of
them, filled with oil, sitting around my home for at least two years. These
are glazed with at least three very different glazes, so I'm leaning toward
crediting the clay body for the tight seal.
Unfortunately, it's a pre-mixed (^6) body from a small factory in Sioux
Falls, SD, so that doesn't help you much. The point is, though, that if you
experiment with different clay bodies, you have a chance of finding one that
will suit your purposes. Personally, though, as much as I love clay, I
prefer to keep my oil in glass bottles so I can see the herbs I put in
there, and also to allow for a visual check on the quality of the oil.
Cindy Strnad
Earthen Vessels Pottery
Custer, SD
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