The Golden State: Where & How to Live, Secure, Visit, Enjoy and Thrive in California
Coloring Finishing And Painting Wood
Bleaching powders produce a whitening by a reaction of chlorine upon ordinary slacked lime when made into a thin paste with water. For walnut and some other woods, and especially for floors, this bleaching agent has been found to be quite satisfactory. The bleaching paste or solution must be mopped or brushed onto a floor promptly because the active chloride of lime is an unstable compound which decomposes rather quickly under ordinary conditions when it is moist or wet. After bleaching, the chemicals should be sponged or mopped off with clean water in order to prevent any future bleaching or any unwanted reaction with the finishes.
The ordinary bleaching powders of chloride of lime are wet with water, which brings about a chemical reaction that produces the active bleaching agent called calcium hvpochlorite (Ca(OCl)2) and also calcium chloride (CaCl2). Very recently reports have come from chemical experimenters that, tho calcium hvpochlorite is a good bleaching agent for wood and is easily obtainable from bleaching powders, they had found sodium hvpochlorite (XaOCl) in solution to be still better, and that the last-named chemical left the surface of the wood in better condition for finishing than when calcium hvpochlorite made from bleaching powder is used.
When chloride of lime paste is used for bleaching floors and other wood surfaces, it should be mixed into a thin paste prior to application and cleaned off before it becomes quite dry. If further bleaching is needed, a No. 2 solution of sodium carbonate (Na2Co3) should be applied before the wood has become completely dry. The No. 2 solution is made by placing a pound or a little more of the dry sodium carbonate salt into a gallon of hot water.
Dust from sanding of bleached floors and other large surfaces is quite irritating if the finisher forgets to wear a dust mask or wet sponge over his nose.
348. Commercially Prepared Two-Solution Bleaching Agents.—The demand for prepared, very strong bleaching agents for wood that really bleach, has become so great that there is at least one firm that has placed on the market a two-solution bleach which is sold under the name of Simpson's Bleaching Solutions No. 1 and No. 2.1 These bleaching agents may be substituted for the potassium permanganate and sodium bisulphite bleaching solutions suggested for use in the "Instruction Sheet for Platinum or Blond Maple," which follows. Rubber gloves should be worn and rubber-bound brushes should be used in applying these strong bleaching agents.
349. Procedure after Bleaching.—"Wood surfaces, in general, should be sponged off with clean water in order to remove any chemicals that have not been neutralized and which might have objectionable reaction to the wood, or to the finishes which are applied over the bleaches. The surfaces of wood which have been bleached or wet with water should be allowed to dry out thoroly, after which they need careful sanding with No. 2/0, and then with fine sandpaper (No.4,0).
