Cindi Anderson on mon 10 dec 01
I also found Ivor's technical definition very interesting as I like to know
why things work.
But I already knew it did work because that is how I have been doing it. A
couple years ago when I was getting started, I had a workshop with Mary Law
and she said she had stopped using slipping/scoring when she saw (I want to
say Warren MacKenzie but I can't swear... it was somebody famous) had
stopped. He told her that he found the slip/scored things always fell off
more. So she tried it and realized he was right. So I started
experimenting and found the same thing. I usually use pure vinegar.
What Ivor's explanation made me realize is there are probably times when
slipping and scoring is better, and I need to learn those times. And now I
have something technical to explain, when people see me not slipping and
scoring and start to lecture me about how it's not going to hold!
Cindi
Fremont, CA
Kate Johnson on mon 10 dec 01
Ivor wrote, regarding deflocculants, magic water (which is....?), vinegar,
etc., as opposed to slip joins:
"In the former case we rely on the force of electrons between clay and water
to hold the parts together. It is a precision process. In the latter we
create a mechanical key so that one part is deformed and forced into the
cavities made in the other part with a fork, needle tool or other sharp
object. This is similar in action to a dovetail joint. I would reserve it
for pieces which are thick, liable to high stress and where there is further
modelling to be done.
I am finding this all very interesting. I began playing with clay when I
took a class at age 8--that's where I first learned about slip to join
pieces of clay. Now I'm half a century older and JUST learned about Peggy's
spooze (long hiatus there...), which I did use to repair a little greenware
tea bowl that the leg had popped off of. It did very well indeed in the
bisque firing and I was well pleased.
Now I am wondering...are we talking about using similar concoctions,
vinegar, etc., to join clay parts as a regular thing, not a last ditch
try-to-save-it effort?
I made two very nice pinch pot pipkins, using the old scratch and slurry
method. Both had legs pop off in bisque firing. I THOUGHT I'd used enough
slip, and thought I'd made sure there were no air bubbles left in the scored
area, but nonetheless, one leg popped off of each of them.
(They would have been subject to stress, though, as I planned to cook over
embers with them perched on their 2 1/2" long legs...)
Might vinegar or spooze or magic water, whatever that is, have worked as
well as/better than the slip, which didn't? Or anyone have any other ideas
about that I might have done wrong?
The plan, by the way, is--for experimental purposes--to replace the legs
with Ten-X, which is apparently meant as a firebrick mortar. You can't
glaze over it, which is my main concern at this point. Is there a better
solution, now that they are both already bisque fired? (Yes, I know, throw
them out and start over, but I'm LEARNING here.)
Best--
Kate
BobWicks@AOL.COM on tue 11 dec 01
In a message dated 12/10/01 11:58:07 PM Eastern Standard Time,
graphicart@EPSI.NET writes:
> Might vinegar or spooze or magic water, whatever that is, have worked as
> well as/better than the slip, which didn't? Or anyone have any other ideas
> about that I might have done wrong?
>
>
Kate:
Your problem is very simply solved. Always dampen both pieces of clay to be
joined before you use spooze. If one piece is dry it will fall off every
time. Dampen your clay first and let it set and then dampen it again and
then when you use spooze it should stay there. If it falls off you will know
that one piece was too dry.
Bob
Kate Johnson on tue 11 dec 01
Hi, Bob...
> Kate:
> Your problem is very simply solved.
Um, unfortunately no it isn't.
Always dampen both pieces of clay to be
> joined before you use spooze. If one piece is dry it will fall off every
> time. Dampen your clay first and let it set and then dampen it again and
> then when you use spooze it should stay there. If it falls off you will
know
> that one piece was too dry.
Yup, that's what I did with the little tea bowl...someone here had told me
to wet both sides of the bone dry piece several times, then use it.
What I meant this time was in the building the piece itself. I had just
made the pinchpot body...it might have been approaching leather hard, but
not really. The leg was just freshly made too--so neither was dry, and in
that case I was using slip rather than spooze.
Advice still stand under these different circs?
Thank you!
Best--
Kate
>
> Bob
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
>
Martin Howard on tue 11 dec 01
There was a lost of chat about vinegar for joining handles as opposed to
scratch and slurry some while ago.
I tried both methods and still not sure which is best.
What does work though, is getting both pot and handle at the same water
content. That needs very careful watching, feeling and planning. But it's
worthwhile.
I love to hear the scientists on list discussing this.
There must be some way of knowing if deflocculating the clay with vinegar on
each side of the join makes the join stronger or weaker.
Some swore they would never use vinegar for a handle join.
Others went the other way. Quite confusing.
My problem is that I like to do as much dipping and pouring of clay slip
before putting on handles. I've then got to be very precise at the handle
join, or find a way of slipping after putting the handles on and not have
the top and rim or the pot near the handle flop onto the shelf as the slip
softens the pot out of leather hard.
Perhaps spraying is the better method.
Martin Howard
Webbs Cottage Pottery
Woolpits Road, Great Saling
BRAINTREE, Essex CM7 5DZ
01371 850 423
martin@webbscottage.co.uk
http://www.webbscottage.co.uk
This web-site is being updated NOW!
BobWicks@AOL.COM on tue 11 dec 01
Kate:
I neglected to suggest to you that you should wrap the complete project in an
air tight bag so that everything dries at the same rate. If you have a small
appendage on your project, it will dry first. This is bad and that is why I
always dry my projects slowly and this works best if everything is tightly
wrapped in plastic for a day or so. I'm confident you will see that this
works. Good luck and Merry Christmas.
Bob
Steve Mills on thu 13 dec 01
Martin,
Your comments on the relative wetness of pot and handle are very
interesting. For a long time now I have only used two methods of joining
clay together: for pulled handles I have always dipped my little finger
in water and scored the pot with the finger nail, the mixture of water
and the movement of scoring creates enough slurry to make a good join,
the pot is always drier than the handle, as I pull directly on the pot.
For all other types of joining I use a wet toothbrush which does the
same job but over a great area. I have never found a need to change
these techniques either for earthenware or stoneware. I reserve vinegar
for mixing with reclaimed clay to speed souring, and for joining dried
clay pieces together.
Steve
Bath
UK
In message , Martin Howard writes
>There was a lost of chat about vinegar for joining handles as opposed to
>scratch and slurry some while ago.
>I tried both methods and still not sure which is best.
>What does work though, is getting both pot and handle at the same water
>content. That needs very careful watching, feeling and planning. But it's
>worthwhile.
>
>I love to hear the scientists on list discussing this.
>There must be some way of knowing if deflocculating the clay with vinegar=
> on
>each side of the join makes the join stronger or weaker.
>Some swore they would never use vinegar for a handle join.
>Others went the other way. Quite confusing.
>
>My problem is that I like to do as much dipping and pouring of clay slip
>before putting on handles. I've then got to be very precise at the handle
>join, or find a way of slipping after putting the handles on and not have
>the top and rim or the pot near the handle flop onto the shelf as the sli=
>p
>softens the pot out of leather hard.
>
>Perhaps spraying is the better method.
>
>Martin Howard
>Webbs Cottage Pottery
>Woolpits Road, Great Saling
>BRAINTREE, Essex CM7 5DZ
>01371 850 423
>martin@webbscottage.co.uk
>http://www.webbscottage.co.uk
>This web-site is being updated NOW!
--
Steve Mills
Bath
UK
| |
|
