Martin Howard on wed 14 aug 02
As I have mentioned before, I had a lot of problem dipping mugs and teapots
in slip.
The handle and part of the wall of the pots fall off, simply due to gravity
and the slip softening the pots.
So, for such items, I have started applying the coloured slips after the
first firing.
It seems to work. The colours are slightly different to when the slips are
put on at leather hard stage, but they adhere and I see no crazing or
cracking.
BUT, can some of the worthy experts on this marvellous list tell me, with
chapter and verse, if I really am doing something stupid and should change
my ways forthwith?
The slip is the white version of my basic red earthenware clay, with 10%
stains and oxides added.
The clear glaze seems to adhere and fit well over the slip. No flaking,
except with some once fire glazes, which I have learnt to avoid for this
process.
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
Updated 6th July 2002
Timakia@AOL.COM on wed 14 aug 02
Martin you are either making a breakthrough with slip, or you are lucky, or
there are enough glaze components in your clay to allow you to slip bisque
ware. I want to predict that your problems are not over yet.
What temperatures do you bisque at? Does your clay shrink at this
temperature?
How thick do you slip?
Do you know the recipe of your clay?
The logical problem here is the shrinking of your clay in the bisque process,
versus the lack of shrinking yet in the slip.
My suggestion will be that if you really want to get all problems out of the
way, you will have to add some glaze components to your slip and change it to
an englobe. The very first time that there is a slight change in your
surcumstansas,your slip will start peeling or flaking.
Hope this is worth a penny
Antoinette Badenhorst
http://hometown.aol.com/timakia
105 Westwood circle
Saltillo, MS
38866
Snail Scott on wed 14 aug 02
At 09:06 AM 8/14/02 +0100, you wrote:
>As I have mentioned before, I had a lot of problem dipping mugs and teapots
>in slip.
>The handle and part of the wall of the pots fall off, simply due to gravity
>and the slip softening the pots.
The wetter the underlying clay, the less is will
absorb additional moisture. Some clay bodies are
more absorbent than others while damp, though.
If you're dipping your slip as early in the drying
process as possible (early leather-hard) and it
still gets too wet, you may just have to go to a
bisque application, since it seems to work for you.
Another option: a deflocculated slip will contain
much less water while still being just as liquid.
(Sometimes I even just add colorants to slip-casting
slips and use those, as a 'quickie'.) Less water =
less absorption into the clay, and less shrinkage
too, so it can be applied later.
-Snail
Steve Mills on sun 18 aug 02
If it works DO IT!
I think it was Soldner who said (in effect): Once you begin to get the
hang of this Clay thing, throw the *Rule Book* out of the nearest window
and make up your own as you go along based on experience.
Works for me!
Steve
Bath
UK
In message , Martin Howard writes
>As I have mentioned before, I had a lot of problem dipping mugs and teapo=
>ts
>in slip.
>The handle and part of the wall of the pots fall off, simply due to gravi=
>ty
>and the slip softening the pots.
>
>So, for such items, I have started applying the coloured slips after the
>first firing.
>It seems to work. The colours are slightly different to when the slips ar=
>e
>put on at leather hard stage, but they adhere and I see no crazing or
>cracking.
>
>BUT, can some of the worthy experts on this marvellous list tell me, with
>chapter and verse, if I really am doing something stupid and should chang=
>e
>my ways forthwith?
>
>The slip is the white version of my basic red earthenware clay, with 10%
>stains and oxides added.
>
>The clear glaze seems to adhere and fit well over the slip. No flaking,
>except with some once fire glazes, which I have learnt to avoid for this
>process.
>
>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
>Updated 6th July 2002
--
Steve Mills
Bath
UK
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