CHAPTER VIII. 



Cements, Mortars, Paints and Glues. 



Cement and Mortar.— 



Cements for Iron.— 1. Sal ammoniac, 2 ozs. ; sulphur, 

 1 oz. ; clean iron-boring-s or filings reduced to powder, 12 lbs. ; 

 water enough to form a thin paste. 



2. Sal ammoniac, 2 ozs. ; iron-filings, 8 lbs. ; sufiBcient 

 water. • 



3. 1 or 2 parts of sal ammoniac to lUO of iron filings. 

 When the work is required to set quickly, increase the S9,l 

 ammoniac slightly and add a small amount of sulphur. 



4. Iron-filings, 4 lbs. ; pipe-clay, 2 lbs. ; powdered pot- 

 sherds, 11 lbs. ; make into a paste with moderately strong 

 brine. 



5. Equal parts of red and white lead, mixed into a paste 

 with boiled linseed oil. Used for making metallic joints of 

 all kinds. 



6. To 4 or 5 parts of clay, thoroughly dried and pulverized, 

 add 2 parts of iron-filings, free from oxide, 1 part of peroxide 

 of manganese, }4, of sea salt and X of borax ; mix Avell, and 

 reduce to a thick paste with water. Use immediately. Ex- 

 pose to warmth, gradually increasing almost to white heat. 



7. Sifted coal-ashes, 2 parts, and common salt 1 part. Add 

 water enough to make a paste and apply at once. This is 

 also good for stoves and boilers, as it stands heat. 



Boiler Cements.— 1. Chalk, 60 parts ; lime and salt, of 

 each, 20 parts ; sharp sand, 10 parts ; blue or red clay and 

 clean iron-filings, of each, 5 parts. Grind together and cal- 

 cine or heat. 



2. Powdered clay, 6 lbs. ; iron-filings, 1 lb. Make into a 

 paste with linseed oil. 



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