Wiseman Ceramics

Additive A is a Lignosulphate, mainly used to produce plasticizers for the concrete, cement, and brick industry. I experimented with Additive A/ Type 2 in my porcelain for several months… I was able to acquire a 40 lb minimum at one point; however in the U.S., you may have to purchase hundreds or even thousands of lbs at a time from Borregaard LignoTech.

I was attempting to use Additive A -Type II to enhance my clay’s green strength, but found only marginal strength increases until the ware dried completely.
On that note, if you add more than just 1-2% and let it go to bone dry, it will dull even the best steel trimming blades within minutes. There is also a thin, but even harder, transpiration produced outer crust that is nearly impossible to cut through (imagine trimming dense plastic or wood).

As I said above, it is used as a plasticizer. But there are certainly better options when aiming for increased plasticity in clay (V-gum, CMC, MgSO4, Ball Clay…), so if this is the goal, Additive A wouldn’t be my first recommendation. It’s also important to note that lignosulphates are used as a deflocculant, which under normal conditions is the last thing you’d want to add to a throwing body.
The plasticity that it yielded was an odd one. It felt more like throwing a slime infused low-fire Redart body (sorry, best description I can give). It was neither naturally plastic or “rubbery”, but had a feel all it’s own.

I have heard of pottery studios and classrooms using small amounts (around 0.5%) of lignosulphate products to keep greenware from chipping –especially in terms of a public or commercial environment where pieces are handled often. However, the trade off can be difficult to get used to.
Right away, the resulting Additive A clay I mixed up smelled like dog food –and shortly thereafter, like dog “dood“!
I found the clay to work best after about 1-2 weeks of aging, but the smell permeated my skin and lingered on my hands for hours… sometimes even days. After pugging and aging for just a little over a month, the resulting clay had developed a non-plastic “black rot core” that was difficult to wedge back into a throwable condition.

Additive A will destroy the water absorption benefits of plaster, wood/Masonite, or bisqued tile throwing bats. In terms of casting slips, it will have the same result on plaster molds. A container with a 1/4 pound of liquefied Additive A once spilled onto my concrete studio floor… the resulting sticky mess took about an hour to clean up, & the stain is still visible (hey, I was gonna seal the floor anyway…).

I was also able to acquire some small samples of Lignotech’s Goulac and Ultrazine NA products. Although I experimented less with these, my limited experience with them did not make me want to continue.

Further Info:

DigitalFire Article: Additive A

“What Every Pottery Should Know” By Jeff Zamek

Has anyone seen the commercial concerning a popular allergy medication where a sculptor (wearing eye protection -but no dust mask) is creating from a block of stone with what appears to be an angle grinder? Airborne particles visually fill his immediate area as he works –then the scene cuts, and he says he uses _______ for all his allergy issues…
The next time I saw it, I noticed a cat sitting in the room with him. Were they honestly trying to insinuate that the cat dander is the real concern for this guy’s nasal, bronchial, and lung tissue irritation?

Silicosis is the result of silica (from clay, stone, glass, etc.) dust, which is toxic to the lining of the lungs. When silica particles contact lung tissue, a strong inflammatory reaction occurs. Over time, this inflammation causes the lungs to become irreversibly damaged. This falls under the term fibrosis, a condition which is both debilitating and deadly.

From the searching I’ve done, the “sculptor” is portrayed by actor Jon Eric Preston. On the medicine’s official website, all the actors are “representative of the real symptoms that allergy sufferers experience and the clear relief that ________ delivers in many real life situations”.

Ok -well, in real life Preston is skilled at many things from snake handling to firearms. Perhaps next they’ll ask him to do an adhesive bandage commercial where he acts out the fine art of Russian Roulette…

Related links:

U.S. Department of Labor: Facts on Silicosis

Silicosis and Screening by Edouard Bastarache

The specific gravity of a liquid is simply the weight of the dry components in relation to the water. If the specific gravity of your glaze or slip changes too much, you could be applying too much or too little, which may prevent you from getting repeatable results. Finding the correct specific gravity for your methods is part of a trial and error process. As a starting point, the target for most glazes and slips is between 1.50 -1.80. Once you have found what works best, taking and recording a measurement will allow you to adjust the glaze as it loses water during use, storage, etc.
I usually try to keep my glazes within a “certain window”, and use the specific gravity as a guide for returning to, when things get far enough off. Having said that, some of my glazes are extremely application sensitive (Reddn’d Rainbow is a good example), so I’ll take particular care to be accurate with those.

Since the weight of 100ml of distilled water equals 100 grams, the best way to get a reading is by taking a 100ml sample of your glaze or slip and weigh it using an accurate scale and a graduated cylinder.
Tare the scale to the weight of the graduated cylinder, and carefully fill it to the 100ml mark.

Example:
(100ml water = 100grams)
100ml slip/glaze = 160grams.
The specific gravity is said to be 1.6, as it is 1.6 times the weight of water.

If the Specific Gravity is too high, you can lower it by adding water.
Take care to add only water (not gum solution). The binder or suspension agent does not evaporate with the water, so the water content alone is all that needs adjusting. Also, understand that it takes much less water than you think to thin a glaze, so adjust a little at a time.
If the specific gravity is too low, add more dry materials in the correct proportions regarding the clay or glaze formula.

Temperature also plays a role. In the winter, I have my studio thermostat programmed for a lower temperature during the late night/ early morning hours when I’m not working. I have therefore noticed a difference when measuring the specific gravity first thing in the morning, as compared to later after the heater’s been running for several hours. I get past this by blending the glaze for a few minutes each time I take a reading. Be careful not to blend too long, as the high shear friction can cause the liquid to heat up and skew the reading.
To be really precise then, the readings should actually be done with a thermometer as well.

In a future post, I will discuss how Viscosity/Rheology factors into all of this.

Relevant Links:

Getting Started with Crystalline Glazes

Reading, Calculating, & Measuring a Glaze Recipe

Adding Water & Suspenders/Binders to a Glaze

Glaze Application: Spraying & Spray Guns