Litharge cements

Similar reactions have been employed to form polystannoxanes and mixed lead-silicon polymers. The lead-containing polymer, glycerin-litharge cement, exists as a mixture of chains and crosslinks . 

Litharge cements Sulfur cements Hydraulic cements... 

It is quite necessary that the welding of the tank is perfect and free from pin holes. Leaks frequently appear where the tubes are welded in the top of the tank. These may be eliminated by brazing the joints. A less satisfactory way is to use a cement of litharge and glycerol. This cement may also be used with success on leaky valves. Occasionally leaks occur in the rubber tubing or its connections with the bottle or tank, but these are unusual. 

This cement may be applied on cracks but not on joints because it becomes as hard as stone on standing. A litharge putty may be prepd by mixing 73 ps of litharge, 8 ps of flock asbestos and 19 ps linseed oil. The mixt sets in about 7 days and resists acids up to about 50% strength. The so-called "German putty consists of 70 ps quartz flour, 8.5 ps fluosilicate, 1.5 ps clay in 20 ps of water glass (NaaO 20, SiOa 60 and... 

A somewhat crude though convenient classification can be made on the basis of the principal ingredients, thus. (1) Portland cement, (2> high alumina cemenl. (3) sodium silicate. (4 magnesium oxychloride plus copper powder, (5) litharge or red lead plus glycerol. (6) rubber latex, and (7) synthetic resins. Supplementary materials to be considered are asbestos, white lead, plaster of Paris, sulfur, graphile, sand, pilch, tar, rosin, and boiled linseed oil. 

Mortars used in the past have primarily been composed of Portland cement, silicates, and litharge and glycerine. Except for Portland cement, these traditional materials have generally been replaced by resin mortars utilizing epoxy, polyester, vinyl ester and furan resins. 

Fluorinated hydrocarbons of fatty consistency can be used for lubricating metal surfaces and taps, with an external seal of piceine. Packing rings of lead, soft iron, or copper are used when connecting metal apparatus. Litharge in glycerol is a suitable cement. 

The resultant HF still contains traces of entrained KF and can be redistilled at 30-35°C into the second receiver. For very pure HF, silver equipment should be used [2Q. Since organic substances are immediately decomposed by HF vapor, joints can be made tight only by means of the Cu cones described. Alternatively fused sulfur may be used, with picein or a like substance covering cracks in the sulfur mass. As a temporary expedient, resulting in not quite anhydrous acid, the seal can be made with well-dried litharge-glycerol cement. 

Mixtures of glycerin and litharge (lead oxide or PbO) are used as adhesives in the repair of tubs and sinks, pipe valves, glass, stoneware, and common gas conduits. A mixture of one part slightly diluted glycerin with two to three parts of lead oxide requires approximately one day to form a crystalline compound. The resulting cement resists weak acids and nitric acid, but reacts with sulfuric acid. These materials have also been used as ceramic seals in potting electronic equipment. 

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