WOOD FLOOR FINISHES One of the most notable developments of lumber manufacture in recent years has been the production of flooring materials of great serviceability from many different woods, the most prominent of which are maple, beech, birch, oak, edge-grain yellow pine, and Douglas fir. The use of such floors has become so popular and widespread that it is worth while to quote from Radford's "Estimating and Contracting" as follows, upon the finishing of floors: "The first thing necessary in order to obtain a good job of floor finishing, is to get a perfectly smooth surface. Until recently the only way to do this was the tedious, back-breaking method of planing and scraping, the latter being done usually with the edge of a freshly cut piece of glasS. When the cutting edge wears down, a fresh piece must be taken. Sandpaper, bent over a flat wooden block, is also used to cut down any roughness or raised grain. Steel wool is preferable for this purpose, on account of the greater rapidity with which it cuts. While this method is still very generally practiced, modern invention has come to the aid of the floor finisher and has produced a planing machine or surfacer that is pushed across the floor like a lawn mower.
"The first operation is filling the wood. Oak and other open-grained woods require filling with a paste filler; and while many painters laugh at the idea of a paste filler upon such woods as yellow pine and maple, experienced floor finishers say that a better job can be done by using paste filler as a surfacer. The method of using is to apply the filler to a strip, say six or eight boards wide, running the entire length of the room. Use a short, stiff brush, and apply across the grain. By the time this strip has been completed, the filler will probably have set sufficiently to rub. It must not be rubbed before setting, or it will be rubbed off the wood; nor must it be allowed to set too hard, or it will be impossible to rub it at all or even to scrape off the filler. When the strip has set just enough, it must be rubbed well into the grain of the wood. After the filler has been thoroughly rubbed, any surplus material must be carefully wiped off with a soft rag. Before anything further can be done, the filler must be given time to dry —not less than 24 hours, and preferably two days.
"If the natural color of the floor boards is not satisfactory, they should be stained before filling; and the filler should be colored with pigment ground in oil, to bring it to the same color tone.
"If there are cracks or nail-holes in the floor, they must next be filled, in order to make a smooth and perfectly uniform surface. This filling may be done by using a pure whiting and linseed oil putty, tinted to match the floor boards; or it may be done better with a whiting and white lead putty made by mixing one part of white lead in oil with two or three parts of bolted whiting and enough coach varnish to make a stiff paste. This putty will resist moisture; and, when dry and hard, it may be sandpapered or rubbed. For large cracks, an excellent unshrinkable putty can be made by soaking blotting paper in boiling water until it forms a pulp, then mixing it with glue dissolved in water. To this, bolted whiting is added in sufficient quantities to make a fairly stiff paste, and thoroughly kneaded. This paste must be pressed into the cracks and smoothed off with a putty knife.
"For those who do not care to make their own putty, there are excellent prepared crack-fillers on the market.
"Wax Finish. By far the best material for finishing hardwood floors is wax, although this involves a little more trouble to keep in good condition. It gives a smooth, satiny luster, without the glaring effect of new varnish, and is not marred by heel-prints such as varnish is subject to. When wax grows dim, it can readily be polished again.
"Some painters advocate the application of the wax directly upon the paste filler; but the best practice is first to give one or two thin coats of pure shellac varnish. Where a slight darkening of the tone of the wood is no objection, orange or brown shellac is preferable to the bleached, since it is stronger. Shellac should be cut with grain alcohol, and not with wood alcohol. It is especially adapted where a hard and quick-drying undercoat is required. On a close-grained wood where a paste filler has not been used, either a thin coat of a first-class liquid filler, or a coat of one part of linseed oil to which from five to ten parts of turpentine have been added, should be given before applying the shellac. Unless there is an undercoating of some kind, it is very difficult to apply the shellac so that it does not show the lap. Even then it requires skill and rapidity of work. In shellacing a floor, the plan of following down a space one or two boards wide should always be followed. The shellac coat should be put on before the oil or liquid filler coat is absolutely dry.