Scientific American 21, 21.11.1859
Messrs. Editors: The communication on page 165, this volume of the Scientific American, on the subject of graphite paint, over the signature of Quarterman & Son, deserves correction. The analysis is wrong; "20 of linseed oil, and 80 graphite" will not make paint. The paint to which they refer has only pure raw linseed oil or graphite in it, but long experience taught the necessity of properly preparing the graphite for grinding; it is this knowledge which enables the company to make the best paint of this kind in the world. The comunication referred to, while admitting the excellence of graphite paint for wood and iron, alleges that it is "not good for copper and new tin," but it very carefully omits to venture any reason for this assertion, which is in the face of the facts. Graphite is, according to all chemical authority, the most indestructible of all materials, insensible to acids and alkalies, to heat and cold, neither contracting nor expanding; being the purest of carbon; rivaling the diamond; it is antiseptic, will prevent and stay rust in iron and decay in wood. It is alike good for new tin as for other substances. Graphite, in the language of Professor Emmons, possesses "a nature unequaled for strength by any substance," it is of great body, and works with marvelous facility. New tin roofs painted 12 years ago, are now apparently as good as when first painted. For bridges and railroad timber, it is the cheapest and most efficient prevention of decay. Graphite will keep the bottoms of vessels clean from grass or barnacles. If the paint be rubbed with fine sandpaper and a hard brush, it will become as smooth as enamel, and can always be kept bright by rubbing. Painters are in the habit of buying the dry graphite and mixing it with oil; this mixture will not compare with the ground graphite paint when properly prepared. Graphite paint effectually excludes damp; being antiattritious it turns water like the back of a duck.
- W. H. W.
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