Jeff Lawrence on tue 15 dec 98
Hello All,
I got a kick out of reading Jeff Zamek's articulo in latest CM on clay
additives. "Lignosulfate" -- now that is an euphonious word. I would be
proud to work for a company call American Lignosulfates, the makers of
Additive A (which isn't nearly so melliphonious...kind of reminds me of
Soylent Green...).
Logodigression aside, has anybody not involved in brick manufacture had
actual dust-on-the-hands experience with this Additive A? Mr. Zamek reports
it adds plasticity without the dirty nasties of ball clay. That it fattens
up overshort clay. If one added the Additive, it seems like you could
substitute kaolin for ball clay to get faster and more even drying ...
maybe whiter whites for crisper glaze colors?
THoughts to inform the inevitable experiments welcome!
Jeff
Grimmer on wed 16 dec 98
Jeff,
I played with Additive A for a bit when I was in grad school on the advice
of Frank Martin. It does, indeed, add plasticity (maybe I should say
flexibility) to a clay body. Its biggest benefit seems to be that it allows
one to manipulate a clay body when it is closer to leather hard without
having cracking problems. I stopped using it because I was decorating with
slips on greenware and singlefiring to C10. The Additive A would frequently
leave a deposit on the dry clay which I didn't like. It burns off cleanly in
the bisque, but I wasn't bisquing, so that was a moot point.
A.A. looks like really dark brown sugar in the bag, and when mixed with
water, smells sort of like soy sauce. Additive A is not people.
Frank Martin (still on this list, Frank?) can tell you lots more about it.
steve grimmer
marion illinois
>----------------------------Original message----------------------------
>Hello All,
>
>I got a kick out of reading Jeff Zamek's articulo in latest CM on clay
>additives. "Lignosulfate" -- now that is an euphonious word. I would be
>proud to work for a company call American Lignosulfates, the makers of
>Additive A (which isn't nearly so melliphonious...kind of reminds me of
>Soylent Green...).
>
>Logodigression aside, has anybody not involved in brick manufacture had
>actual dust-on-the-hands experience with this Additive A? Mr. Zamek reports
>it adds plasticity without the dirty nasties of ball clay. That it fattens
>up overshort clay. If one added the Additive, it seems like you could
>substitute kaolin for ball clay to get faster and more even drying ...
>maybe whiter whites for crisper glaze colors?
>
>THoughts to inform the inevitable experiments welcome!
>
>Jeff
Jim Horvitz on wed 16 dec 98
Lignosulfates were used as an additive to concrete starting in the early
1930's and continuing to date. They are a byproduct of the manufacture of
paper. There use in concrete is to reduce the amount of water necessary to
obtain a given plasticity. In concrete the reduction of water results in an
increase in strength. They work by dispersing the cement particles so they are
more effective. There are many new products used in concrete for similar
purposes that are much more effective. The lignosulfates are however a very
cheap material.
The pigment industry has also used them to disperse pigments.
The oil industry has used them in drilling mud and also as a dispersing
retarder in cementing wells.
I first ran into lignin doing a college chemistry paper in the 1040's and have
found them interesting since. I have not studied clay additives for many years
but expect that there are many new products that work better than Lignin.
Jim Horvitz Rancho Mirage Ca
Louis Katz on wed 16 dec 98
My experience with Additive A is limited but,
I used to add it to extrusion bodies and felt that it helped them extrude
cleaner. I used larger amounts than was normally called for, a couple of cups
in two hundred pounds of dry clay. I did have side by side batches once but
the bodies were not the same so if you want hard science?........
It also increased the dry strenght a whole lot
Additive A does not help spelling.
Also I haven't used it in years, but if I went back into extrusion hard core I
would probably buy some.
Louis Katz
>
--
Louis Katz
lkatz@falcon.tamucc.edu
NCECA Director At Large
Texas A&M-CC Division of Visual and Performing Arts Webmaster (512) 994-5987
Molly Saunders on thu 17 dec 98
I'm new to Clayart, but I'll jump in on this interesting Additive A thread
because I've been experimenting with the sticky, smelly stuff for a few months
now. I work with a clay that we dig with a backhoe out of our back field.
Called Maine "blue" clay, it's a cone 04 earthenware that fires red. The clay
is somewhat short. I've been using it as-is for years, not wanting to add
bentonite, etc., but that's another story. Additive A seems worth trying
because it burns out.
I have found that it does indeed increase plasticity, quite noticeably. It
also increases strength of dry greenware.
I get Additive A from Sheffield in Mass. The way it comes, in a dry powder
full of large lumps , it's hard to handle. I have found that if I add water
and let it sit for several days, it eventually dissolves. I then mix it with
grog and pug it in with the clay.
I have two questions about Additive A:
First, The kind I get from Sheffield has Barium added. The Barium does indeed
eliminate the white scumming, but is it really safe? Jeff Zameck's opinion is
that barium is not hazardous to the potter. I'd like to be sure before I use
it for full production.
Second, what products are formed as the lignosulfate is burned in the kiln?
Since Additive A is a by-product of the paper industry, and paper mills use
chlorine to bleach lignates out of wood pulp, I wonder if there is any danger
of creating dioxins in the firing. This is something I wouldn't have thought
about even six months ago, but we are finding dioxin in our lake here,
pollution from paper mills. I am finally waking up to the realities of using
chemicals.
I'd appreciate any thoughts on these questions and I'd be glad to go into more
detail about my Additive A tests.
Molly Saunders, in beautiful downtown Wayne, Maine
Eleanora Eden on wed 18 jan 12
Hi Bill,
Do you by any chance refer to Agent A? I don't find "Additive A" in the
Laguna lexicon but I do see Agent A and I happen to have a bag full of
it that I bought ages ago to prevent stinky clay. I used it once and decid=
ed
I would prefer stinky clay. Can't remember why.
If it is Agent A I will dconsider giving this a try. Anything that will he=
lp with
cracking is something I like. Any downside?
Eleanora
>As I mentioned in a previous email , my clay body has 8 ingredients in
>it. The particle sizes vary, but so does the mesh size vary in the
>milling process. This helps with tiles in particular from warping or
>cracking. I also use boards to flip tiles when drying and I wax the
>outside of the tiles so the interior dries before the outside of the
>tile. I'm talking about tiles over 20 inches square.
>
>If you want extremely hard green ware, add 1 cup of Additive A per
>hundred pounds of clay. This also helps with any cracking you may
>encounter, especially with highly plastic clay bodies.
--
Bellows Falls Vermont
www.eleanoraeden.com
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