This Glaze Thinner is a solution of sodium hexametaphosphate in water. It is a very powerful thinning agent and should be added very sparingly. For example, 2 or 3 drops in a 4 oz. jar should have a significant effect. It is a useful product for thinning glazes, underglazes, etc. when you do not want to dilute the strength of the glaze by adding water.

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Na2SiO3 Deflocculant, De-flocculant Formula: Na2SiO3 Alternate Names: Waterglass OXIDE ANALYSIS FORMULA Na2O 50.78% 1.00 SiO2 49.22% 1.00 Density (Specific Gravity) 2.40 Melting Point (MP) 1080°C The most popular deflocculant used in casting slips for many years. It is nearly always used with soda ash (when employed alone it can make a slip 'stringy' and thixotropic). The material is effective, reliable and inexpensive. However, it attacks the plaster in molds much more than more modern deflocculants and it is easier to over-deflocculate a slip with sodium silicate. There are potassium based deflocculants that are similar to the corresponding sodium ones. They can be employed where the presence of sodium is undesirable. Soda ash is more suitable for deflocculating glazes. In addition, a wide range of organic deflocculants are available as alkali salts of pyrogallic, humic or tannic acids. They have long working ranges and can increase the apparent plasticity of the clay. As noted, their use prolongs mold life compared with sodium silicate and soda ash and they are less prone of over-deflocculation. Tetramethylammoniumhydroxide is also an organic compound that is used where residues from inorganic salts cannot be tolerated. It is a strong base that can even attack glass and quartz. Also used as a binder in ceramic bodies. ~ from Digitalfire Ceramic Materials Database

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Darvan is a deflocculant and used to disperse ceramic suspensions to minimize their water content. It is a liquid alternative to the long popular sodium silicate. About twice as much is required typically (0.4-0.5%) however Darvan does offer a number of advantages. Typically soda ash is not needed as a complement and Darvan does not attack plaster molds. In addition slurries are much less sensitive to over deflocculation and are more stable. It is thus easier to reprocess scrap. However a number of engineers still prefer using a sodium silicate:soda ash mix to control thixotropic properties better, especially if little scrap is being added. Darvan 811 is a low molecular weight short chain polymer for use in vitreous and semivitreous bodies and glazes. In comparison to the conventional soda ash-sodium silicate system, these polyelectrolytes produce slips with longer casting range, higher solids content, improved viscosity stability, fewer "soda" or "hard spots", and significantly increased mold life. Slips also tend to reclaim better without the need for constant adjustments with more deflocculant. The active agent in Darvan is polyacrylic acid. Its molecules are negatively charged along their length. They attach to clay particles and cause them to repel each other. There are two cautions with this material: -It has a shelf life of two years -Some types cannot go below 40 degrees F without detrimental effects on their performance. Darvan definitely cannot be frozen. In either of these cases, it will simply not disperse your slurry as expected.

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Darvan is a deflocculant and used to disperse ceramic suspensions to minimize their water content. It is a liquid alternative to the long popular sodium silicate. About twice as much is required typically (0.4-0.5%) however Darvan does offer a number of advantages. Typically soda ash is not needed as a complement and Darvan does not attack plaster molds. In addition slurries are much less sensitive to over deflocculation and are more stable. It is thus easier to reprocess scrap. However a number of engineers still prefer using a sodium silicate:soda ash mix to control thixotropic properties better, especially if little scrap is being added. Darvan No. 7 is a high molecular weight, long chain polymer that has been used successfully as a general purpose dispersing agent for both ceramic bodies and glazes. Like 811 and 812, this poly-electrolyte shows the advantages mentioned above. Slips prepared with Darvan No. 7 show little tendency to thicken on standing (thus this version is considered better for glazes). The active agent in Darvan is polyacrylic acid. Its molecules are negatively charged along their length. They attach to clay particles and cause them to repel each other. There are two cautions with this material: -It has a shelf life of two years -Some types cannot go below 40 degrees F without detrimental effects on their performance. Darvan definitely cannot be frozen. In either of these cases, it will simply not disperse your slurry as expected.

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