Glistering Phaeton on wed 5 aug 09
Dear Melinda/David/Nan,
Thanks all for your replies on my grog question. My responses to all =3D
are below, and I easily could be wrong about any of it...
Fireclay instead of grog: I always thought that grog is made of clay =3D
that has been fired to maturity and then ground to a specific mesh size. =
=3D
That would lead me to believe that it wouldn't meld with the Electric =3D
Brown (being vitrified it wouldn't absorb anything), but rather would =3D
retain its light color through the firing process. I also figure I'd =3D
start with what I have on hand and see if I can get the contrast I'm =3D
looking for. Of course, if it ends up looking like crap or doesn't show =
=3D
at all, I'll have to start with a mulcoa replacement strategy. I will =3D
try the sprinkling method you describe for the fireclay though...never =3D
thought of spraying it down before I wedge. I'd probably have just =3D
tried to get it all rolled up before it blew away!
Molochite: I got the 48 and 200 mesh Mulcoa from Laguna here in =3D
California, so I thought I'd give it a whirl and see what it looks like. =
=3D
If it ends up firing without enough contrast then I will definitely =3D
have to find a whiter grog (or fireclay if it looks like grog just won't =
=3D
cut it). I think I'll start with 6% per your suggestion and go up from =3D
there. Maybe 6%, 10%, 15% and see what I get. I'm an avid reader of =3D
this list so I know the testing/record-keeping drill!
Dark slip and wedging: I usually clean all the slip and finger marks =3D
from my pots before I wire them off, so I'm hoping that that would be =3D
enough to show any contrasting grog mixed into the clay. I'll do some =3D
carving as well (these are tests after all!) to see if that makes a =3D
difference in showing the contrast. In terms of the blending process, =3D
it's just me and my hands. What I thought I'd do is take three 400 gram =
=3D
balls of dark clay, roll them out, sprinkle on three different =3D
percentages of grog (24g, 40g, 60g), spray them down, slice and stack, =3D
and then begin the slam wedging process. As Michael Wendt mentioned =3D
back on March 29th, "20 doublings creates over 1,000,000" layers so I'm =3D
hoping it will be pretty well mixed.
Thank you all again for your advice, and I will certainly keep you =3D
posted with the results.
=3DE2=3D80=3D94Adam
-----Original Messages (drastically edited)-----
--snip--
Goldart fireclay
--snip--
Molochite
--snip--
dark slip will cover the lighter grog
--snip--
Date: Mon, 3 Aug 2009 14:22:48 -0700
From: Glistering Phaeton
Subject: Adding grog
I want to add some white grog to my dark brown claybody to see if it =3D
will make nice contrasting speckles. I know I need to test, test, =3D
test...but my two questions are: =3D20
1. What ballpark percentage grog should I start with? I don't want to =3D
start testing 3% by weight if that's not going to have any effect. Does =
=3D
anyone have a rough target I can work either side of until I get the =3D
effect I'm looking for?
2. I plan on sprinkling the grog onto a slab of clay (dust mask firmly =3D
in place). Since I'm adding the dry grog to wet clay, would slam =3D
wedging be the best way of evenly mixing the two? The only equipment I =3D
have is my hands.
If it matters, my grog is Mulcoa (I have both 48 and 200 mesh; thought =3D
I'd start with the 48 for best visibility) and the clay I'm using is =3D
Laguna's cone 5 Electric Brown (WC=3DE2=3D80=3D91866).
Any guidance would be appreciated, and if anyone's interested, I'll post =
=3D
my tests online when they come out.
Thanks!
=3DE2=3D80=3D94Adam
Snail Scott on wed 5 aug 09
-
On Aug 3, 2009, at 4:22 PM, Glistering Phaeton wrote:
> I want to add some white grog to my dark brown claybody to see if it
> will make nice contrasting speckles...1. What ballpark percentage grog
> should I start with?
The finer the grog, the less it will alter the
working properties of the clay, so you can
add more fine grog than coarse. I'd start
with 5% increments. 200 mesh is too fine
for much -visibility, though. Use the 48.
If you really want grog to show, lightly scrape
the surface after it's stiff leather-hard. This will
remove the covering of brown clay and expose
the grog clearly. You can use technique just on
limited parts of the piece for contrast, if it suits
your intentions. Some glazes are prone to
pinholing over a raw scraped surface, so
smooth it a bit after scraping.
Personally, I hate the look of white grog in
brown clay. I used to use the Muddox firebrick
grog, for its softer yellow color. (Anybody have
a good substitute available in the Midwest?)
-Snail
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