Painting.
In order to use paints and oils economically, a clear understanding of their purpose and action is absolutely necessary. Linseed oil is said to “dry” after being applied. That is only partially true. It rather oxidizes and changes to a tough, gummy substance not unlike hard glue. This action is accelerated by the use of “driers,” as they are called. But in no case does it give the same results as when left to dry of its own free will. The carbonate of lead or mineral which is added to the oil gives the color and assists in making up the body. The life of the paint is the oil, and when it is oxidized, it alone is the binding element. Upon it depends the durability of the paint. A piece of wood dipped in linseed oil and hung up to dry, or oxidize, in the air, will soon become covered with a beautiful translucent film of oxidized oil, which grows harder daily. It will take a high polish and preserve the wood. Another piece dipped in carbonate of lead, or mineral, mixed in turpentine, or any fluid to allow it to spread evenly over the surface, will when dry have a dead or flat color without polish or body to bind it together, and the slightest abrasion will remove portions of it. All painting is done either with pure oils or with the admixture of a fluid like turpentine, which assists in the distribution of the mineral, but does not add to the body. When the surface of wood has been covered with a thick coating of oxidized oil, it can be washed and rubbed to look clean and polished. Boats, when of a light color, are often painted with a mixture containing much turpentine, in order that all marks may be removed with a little beach sand, by rubbing off the mineral, which is not bound together securely by oil, but only loosely by turpentine. Car builders now often paint their cars or varnish them a second time soon after the first, say after about six months’ run. This gives them a good coat of oxidized oil to withstand the weather and preserve the wood. A few coats applied within short intervals produce a fine covering which is very durable and will take a polish after washing.—Master Mechanic.