508 MASON WORK. CEMENTS, PAINTS, GLUES, WAXES 



10. Powdered litharge, 2 parts ; silver sand and slaked lime, of 

 each, 1 part ; boiled oil enough to form a paste. 



These cements are used for stopping leaks and cracks in boilers, 

 iron pipes, stoves, etc. They should be applied as soon as made. 



Tar cement. 



11. Coal-tar, one part ; powdered slate (slate flour), three or four 

 parts ; mix by stirring until thoroughly incorporated. Very useful 

 for mending watering-pots, barrels, leaky sash, etc. It remains some- 

 what elastic. It does not adhere to greasy surfaces. It will keep for 

 a long time before using. 



Copper cement. 



12. Beef blood thickened with sufficient finely powdered quicklime 

 to make it into a paste is sometimes used to secure the edges and rivets 

 of copper boilers, kettles, etc. Use immediately. 



Fireproof or stone cement. 



13. Fine river sand, 20 parts ; litharge, 2 parts ; quicklime, 1 

 part ; linseed oil enough to form a thick paste. Used for walls and 

 broken stonework. 



Earthenware cement. 



14. Grated cheese, 2 parts ; powdered quicklime, one part; fresh 

 white of egg enough to form a paste. Use as soon as possible. 



For fine earthenware, liquid glue may be used. 



Cement for glass. 



15. Wood alcohol to render liquid a half dozen pieces of gum-mastic 

 the size of a large pea ; in another bottle dissolve the same quantity 

 of isinglass, which has been soaked in water and allowed to get surface 

 dry, in 2 ounces of methylated spirit ; when the first is dissolved 

 add two pieces of gum-galbanum or gum-ammoniac ; apply gentle 

 heat and stir ; add the solution of isinglass, heat again and stir. Keep 

 in a tightly stoppered bottle, and when used in boiling water. 



Sealing cements. 



16. Beeswax, 1 pound; resin, 5 pounds. Stir in sufficient red ocher 

 and Brunswick green, or lampblack, to give the desired color. 



