Valice Raffi on tue 18 nov 03
After searching the archives, I'm still a tad confused about using CMC...
I mixed it according to the directions I was given:
12.5 grams CMC
1 pt. hot water
blended & allowed to sit overnight
I thought it was supposed to make a gel, but it is a thick water
consistancy, is that ok?
Also, When I add it to a glaze, should the glaze be thicker than normal to
account for the wetness of the CMC solution? (in case it matters, the
glaze is Hansen's 20x5 w/ 10% zircopax). I'll be brushing the glaze on,
except for the interiors of cups and bowls, where I'll be pouring it.
Should it be mixed into the entire batch, or just into what I'll be using?
(will it make the batch go bad?)
thanks,
Valice
in Sacramento
Dave Finkelnburg on tue 18 nov 03
Valice,
You should be more concerned about how much CMC you use in your glaze --
how many dry grams of CMC per dry grams of glaze. If you mix the CMC thick,
it is a gel, thin it's as you describe. Yes, when you add this CMC solution
to a glaze, you add water also and reduce the glaze density.
You can, if you want, simply dry mix the CMC into the other glaze
ingredients and then pour that into water, let slake and mix. The premixing
you have done does let you add CMC to an already mixed glaze.
You should be aware CMC is an organic material (has carbon in it) and
thus is food for bacteria. In some glazes it will get eaten by bugs over
time. The glaze will then smell and the CMC's effects will diminish.
:-( CMC works best in glazes that will not sit in the studio too long.
Good potting!
Dave Finkelnburg in the dark (as usual?) since daylight has yet to
arrive in this winter-cooled climate...
----- Original Message -----
From: "Valice Raffi"
Sent: Tuesday, November 18, 2003 5:18 AM
> After searching the archives, I'm still a tad confused about using CMC...
> I mixed it according to the directions I was given:
> 12.5 grams CMC
> 1 pt. hot water
> blended & allowed to sit overnight
>
> I thought it was supposed to make a gel, but it is a thick water
> consistancy, is that ok?
>
> Also, When I add it to a glaze, should the glaze be thicker than normal to
> account for the wetness of the CMC solution? (in case it matters, the
> glaze is Hansen's 20x5 w/ 10% zircopax). I'll be brushing the glaze on,
> except for the interiors of cups and bowls, where I'll be pouring it.
>
> Should it be mixed into the entire batch, or just into what I'll be using?
> (will it make the batch go bad?)
Snail Scott on tue 18 nov 03
At 04:18 AM 11/18/03 -0800, you wrote:
>After searching the archives, I'm still a tad confused about using CMC...
>I mixed it according to the directions I was given:
>12.5 grams CMC
>1 pt. hot water
>blended & allowed to sit overnight
This is WAY more precision than I've ever bothered with.
When I actually do pre-mix it, I just throw it in with
a bunch of water to dissolve. That gets added with the
rest of the water when I make the glaze. How much water
doesn't matter much, but I only use as much CMC as I'll
need for that glaze batch. Maybe a pinch for a quart of
glaze, then see how it does, maybe add more if needed.
Most of the time, though, I add it dry. It makes little
tapioca-looking beads in the glaze the next day, then I
give it a good mixing. Works for me.
-Snail
| |
|
