Snail Scott on tue 21 may 02
At 12:31 PM 5/21/02 -0400, Marianne wrote:
>I am only now beginning to try and dip pots into one or two glazes that I
know I like. However, I seem to be getting the glaze coat too thick to
suit me.
Thinning the glaze is one option, but tends to
allow more settling. Bisquing to a higher
temperature may be preferable. You can also
moisten your bisque before dipping, though this
requires consistency just like the glazing does.
Remember, if you double-dip, you're getting a
much thicker coating than a single dip, in
addition to the possibility of making a much
runnier combination, so using one of the
above thinning strategies may be necessary
for double-dipping, even if your single-coat
versions are fine.
>My glaze mixture looks thin enough but if I stick my thumb in, my
fingernail remains coated. I think I previously read that the glaze should
slid off the fingernail. Or was that a joke?
You can't really make a rule about how thick
an unfired glaze coat should be, since some
materials are bulkier in their raw form than
others. A glaze made mainly of frits may need
a fairly thin coating to achieve the same
fired effect as a glaze made mostly of gerstley
borate, for instance. And, some glazes look
better thin and others are better when thick,
never mind differences of opinion about what
constitutes 'better'. Only testing will tell
you what makes your glazes look best to you.
-Snail
Marianne Lombardo on tue 21 may 02
I am only now beginning to try and dip pots into one or two glazes that =
I know I like. However, I seem to be getting the glaze coat too thick =
to suit me.
Can someone advise me, how many seconds should I hold a pot under the =
glaze? Example glaze: Waterfall Brown.
My glaze mixture looks thin enough but if I stick my thumb in, my =
fingernail remains coated. I think I previously read that the glaze =
should slid off the fingernail. Or was that a joke?
Marianne Lombardo
Omemee, Ontario, Canada
John Hesselberth on tue 21 may 02
on 5/21/02 12:31 PM, Marianne Lombardo at mlombardo@NEXICOM.NET wrote:
> I am only now beginning to try and dip pots into one or two glazes that I
know
> I like. However, I seem to be getting the glaze coat too thick to suit
me.
>
> Can someone advise me, how many seconds should I hold a pot under the
glaze?
> Example glaze: Waterfall Brown.
>
> My glaze mixture looks thin enough but if I stick my thumb in, my
fingernail
> remains coated. I think I previously read that the glaze should slid off
the
> fingernail. Or was that a joke?
Hi Marianne,
What is more important than the number of seconds is consistency. I happen
to count to 5, but that's not better than any other number--I just always do
it the same.
When I am learning to properly apply a new glaze I first mix it my standard
way. But then I take several small pieces. One I dip normally, one I
double dip. Then I add 10% more water to a small amount of the glaze and
dip another. Repeat at least once more. Then you can get a good idea of how
thick this particular glaze needs to be to get the results you want. You
can document the right amount of water by measuring specific gravity or by
using a home made viscometer as we describe in our book. See pages 26 and 27
for more detail.
Waterfall Brown needs to be on the thin side. I found I needed to add
10-20% more water than I normally use to get it right--ditto with Waxwing
Brown.
Regards,
John
web sites: http://www.masteringglazes.com and http://www.frogpondpottery.com
EMail: john@frogpondpottery.com
"It is, perhaps, still necessary to say that the very best glazes cannot
conceal badly shaped pots..." David Green, Pottery Glazes
Jeff Tsai on wed 22 may 02
Some glazes will coat a fingernail just as they would any surface. Really,
from the description and because I've never used that glaze, it's hard to
tell whether it's too thick or thin, but if you're having a problem with the
glaze being too think...at least for you, why don't you add some water to
the
glaze.
Then, after mixing the water in really well, take a couple pieces. Dip the
first one in and hold it submerged for 2 seconds, then mark that in your
notebook. Take another one and hold it for 4 seconds, and mark that one
down.
Do the same for 6 seconds, 8 seconds, and 10 seconds. make special note of
how thick your glaze is....then, when the pieces come out of the kiln,
you'll
know how long is best. A lot of times people can't tell you from afar the
"right" way to do something, but I'm sure if you play with it, you'll figure
out what's best.
-jeff
Paul Taylor on wed 22 may 02
Dear marianne.
I dip the pots with a gentle flowing rythum taking the pot out slowly
so the surface tension of the glaze eases the excess off the pot preventing
runs. I do not hold the pot in the glaze at all because I haven't the time.
It goes in and comes slowly out - as fast as you might say that for a mug.
add water till you get the right thick ness. You should weigh a pint of
the glaze when you have it right so you can repeat the same for ever.
With one warning! waite until the glaze has been in the bucket over night
because there will be some salts coming out of the spars and frits that
defloculate the glaze and make it a lot thinner the next day.
I prevent the slop settling by adding vinegar(flocculant) but that is
another variable you could probably do with out. Too much vinegar increases
the amount of water the glaze holds which can push the shrinkage beyond the
dried strength and cause crawling . better to keep stirring and fettle off
the drips when you are new to glazing.
All these rules of thumb like having your finger hairs just showing or the
cuticles can depend on how hairy you are - they are not very helpful. How
much clay is in the glaze can affect it's absorbance. How absorbent your
biscuit is will make enough difference to make glazing a personal thing ,
and yet another skill that improves gradually with practice. I use a feeler
gage to measure my glaze thickness - obviously not every pot. I have ordered
a glaze penomiter (Or something) a fancy name for a point connected to a
measuring devise. it's a hundred 'sobs' and an expense I have managed with
out up till now, but I have to be fussy about my porcelain ( charging a lot
for it ) so the expense is worth it.
--
Regards from Paul Taylor
http://www.anu.ie/westportpottery
The boy who announced that the king had no clothes was tortured for the
names of his confederates and then shot.
> From: Marianne Lombardo
> Reply-To: Ceramic Arts Discussion List
> Date: Tue, 21 May 2002 12:31:24 -0400
> To: CLAYART@LSV.CERAMICS.ORG
> Subject: Dipping Pots Into Glaze
>
> I am only now beginning to try and dip pots into one or two glazes that I
know
> I like. However, I seem to be getting the glaze coat too thick to suit
me.
>
> Can someone advise me, how many seconds should I hold a pot under the
glaze?
> Example glaze: Waterfall Brown.
>
> My glaze mixture looks thin enough but if I stick my thumb in, my
fingernail
> remains coated. I think I previously read that the glaze should slid off
the
> fingernail. Or was that a joke?
>
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