Home › Pottery › Pottery (Take of tin any quantity)

Pottery (Take of tin any quantity)

Take of tin, any quantity, and enclose it in clay or loam and put it in a crucible. Place the crucible in a fire, that the tin may calcine, and then break it. There will be a pound of calx very white, and when it is used to paint with on a white ground, the color will come forth and be much whiter than that of the ground.

Yellow Glazing.

Take of tin and antimony, each 2 lbs.; of lead, 3 lbs.; or, according to some, equal quantities of all the three ingredients. Calcine the whole, and put them at last in fusion, that they may be vitrified. This glazing will run very soon, and be of a fine yellow color.

The calcining the tin, lead, and antimony together, as here directed, would be a very tedious operation. The calcined tin and red-lead should therefore be used, and the antimony calcined alone.

But it is not to be understood that the antimony is to be calcined for this purpose to whiteness, or the state of a perfect calx; which is not easily practicable without nitre, and, if effected, would render the antimony incapable of producing any other color than white. The operation must therefore be performed with a slow fire, by roasting, as it were, the antimony till it loses its metallic appearance, and becomes a greenish powder; as is practised in making the glass of antimony. peated fusions and levigations seem unnecessary.

Another. Take of red lead and white flints, each, 12 parts; and of filings of iron, 1 part. Fuse them twice.

This glazing will be transparent. Care must therefore be taken what ground it be laid upon or it will not answer the end of a yellow, but combine with that of the ground; and, indeed, the body of color is too weak to produce any other than a faint yellowish cast, even on a pure white ground.

Green Glazing to be laid on a White Ground.

Take of calcined copper 1 part, and 2 parts of any of the preceding yellow glazings. Fuse them twice, but when the composition is used it must not be laid on too thick, for that would render the color too deep.

Fine Blue Glazing.

Take of red-lead, 1 lb.; powdered flints, 2 lbs.; common salt, 2 lbs.; tartar, 1 lb. Calcine till it is almost white. White flint-glass, lb., and zaffre, lb. Fuse the whole mixture, and quench the melted mass in water. Repeat the same operation several times. The same proceeding must be adhered to in all the compositions where the tartar enters, otherwise they would be too much charged with salt, and the color would not prove fine. It is proper, moreover, to calcine the mixture gently, day and night, for 48 hours, in a glasshouse furnace. Another. Take 1 lb. of tartar, 1 lb. of red-lead, Another. Take 5 parts of red-lead, 2 parts of powdered bark, 1 part of sand, 1 part of any of the preceding white glazings, and 2 parts of anti-oz. of zaffre; and 1 lb. of powdered flints. Fuse mony. This mixture must be calcined and then fused, and it will give a fine yellow glazing.

Another. Take 7 parts of the mixture of the calxes of tin and lead, mentioned before in the recipe for preparing the masticot for a white glazing. Add 1 part of antimony, and fuse them together.