US2488068A - Method of refinishing old furniture - Google Patents

Description

c. ROMAN 2,488,068

METHOD OF REFINISHING OLD FURNITURE Nov. 15, 1949 Filed April 8, 1949 J71 0671 for, C/zaries Pomazz Patented Nov. 15, 1949 UNITED STATES PATENT OFFICE 2,488,068 METHOD OF REFINISHING OLD FURNITURE Charles Roma-n, Miami, Fla. Application April 8, 1949, Serial No. 88,847 6 Claims. (01. 51-282) The commonly accepted and most widely practiced methods of refinishin painted, varnished or lacquered furniture to again restore the grain of the wood to visibility is to first remove the paint, lacquer or varnish with varnish remover, inone or more steps and tothen sand-paper the surface to such a degree as to expose the original wood. The cleansing of the wood is continued until as much of the paint, lacquer or varnish, as possible, is removed andthe sand-papering is carried right down-to the raw wood. is still'darker than desired, by reason of penetrating stains having been applied to it, .it may be bleached. The wood is then re-finished in the usual and conventional way by the application of lacquers or varnishes, fillers or stains, in any desired order and by these methods a fairly good job of restoring the visibflity of the original grain of any wooden object and especially of old furniture has been had.

However, under the method above described some of the old finishing material such as the filler, lacquer o r varnish originally employed, still clings in the pores and the softer (cellulosic) portions of the grain. My method differs from the procedure above described in that I sandblast the surface to be treated, as presently set forth. By sand-blasting I am not only able to If the wood expose the original surface of the wood with a minimum of labor and cost but I am able to rout out of the pores and recesses delineating the grain, every particle of foreign matter constituting the original finishing coatings. Further, I am able to accentuate the original grain because the sand-blast when judiciously and carefully applied at the right pressure cuts out the cellulosic portions of the wood faster than it does the hard or ligneous portions (lignin) I have found that by judicious selection of the texture and size of the sand granules or other abrasive material, and with practice and use of the proper air pressure and by holding the blasting nozzle at the proper distance from the work, I can safely remove the finish from and restore to a condition for refinishing, the surfaces of very thin wood veneer. Since most furniture of the more expensive types, such as mahogany, walnut and the like, is veneered it follows that my method makes it possible to restore to a condition of great beauty many valuable pieces of furniture which would otherwise be a loss.

In addition, by my method I am able to impart to the cheaper grades of wood such, as for example, poplar, gum, fir and the like which have, in their natural state, little if any visible grain,

2 a very decided grain of such beauty as to cause these cheaper woods, when subsequently finished, to rival in beauty the more expensive woods. This is due to the fact above recited that when gently sand-blasted in thedirection of the length of the grain, the-softer or cellulosic part of the wood yields much more rapidly than the lignin and this quickly produces a pronounced grain characteristic of the particular wood being treated and differing from other woods.

' While the degree of fineness of the sand and the amount of air pressure employed varies somewhat with the hardness of the woods and the ruggedness of the piece being worked upon, i. e., whether solid or veneered, I have generally found that a fine sand discharged at a pressure of from 20 to 85 pounds per square'inch will take care of most jobs because the effectiveness of such blast may, as before stated, he modified to some degree by varying the distance of the nozzle of the blasting machine from the work. However I find it desirable to maintain the nozzle of the sandblasting machine a fairly uniform distance from the work and to control the effect by the degree of pressure employed. This is so because if the nozzle is held too far away the aim of the worker is not accurate and the blast is likely to cut across and destroy the lignin portions of the wood. Since the vast majority of the old pieces of furniture to be restored are veneered with relatively high priced veneers it is very important to so control the blast as not to cut through these veneers. The veneers encountered do not ordinarily exceed a sixteenth of an inch in thickness.

After the old finish has been removed both from the surface and from the pores the wood may be bleached or not according to its color and according to the final finish desired. The wood being then dry and clean, I refinish it in any desired fashion. For example, I may apply one or several coats of lacquer in any color. After this has dried,I apply a coat of glaze or filler which contrasts in color with the first applied lacquer and when this coating of glaze or filler is partially set it is wiped off except for what remains in the pores or depressions of the grain. When this coat of glaze or filler is dry one or two finish coatings of clear lacquer or varnish or,

wax are applied to impart any sheen (gloss, semigloss or fiat) to the finished piece of furniture or other article. While I have placed particular emphasis upon the refinishing of old furniture because of the great adaptability of the method to use in the cleaning out of the original grain of very thin veneer, I have found that this method I to the article.

is also of great utility in the refinishing of wood carvings where repeated applications of paint, varnish or the like have filled and destroyed the fine lines which gave much of the original beauty For example, I have refinished decorative screens, the panels of which presented a multiplicity of intertwined leaves and tendrils in the original carving. Not only was the outside shape of the leaf presented but fine lines were present in the carving representing the veins of the leaves. these fine lines had been completely filled and nothing was left but the bare outside shapes of the leaves and this in a dark brown, almost black, varnish stain. When refinished by my method to present a light silvery appearance this screen again became a thing of beauty with the delicate tracery of the veins of the leaves restored. It would have been utterly impossible to have accomplished this result with ordinary sand-papering because sand-papering would have left the veins of the leaves filled with the original finishing materials. Further many portions of such carvings are inaccessible to successful manual operation. The marked advance presented by my method is illustrated in slight measure in the accompanying drawings, wherein:

Fig. 1 is a photographic reproduction of a piece of mahogany veneer, the left hand end showing old finish, the central section showing the sandblasted surface from which the old finish has been completely removed and the right hand end showing the finished surface in which the grain has been accentuated;

Fig. 2 is a like view in which the wood treated is oak veneer having an original finish of mission oak and;

Fig. 3 is a like view in which the wood treated is a piece of solid gum showing little grain in the left hand old finish section, showing more pronounced grain in the central sand-blasted section and showing marked and attractive grain characteristics in the right hand finished end to which a coating of light colored lacquer has been applied.

While I have described the coatings applied to the finished product as being lacquers or varnishes, glazes or fillers, it is to be understood that the invention resides primarily in the sand-blasting of grained veneers to remove old surface coatings, completely clean the grain from all particles of old finishing materials and, if desired, in addition, to accentuate the grain beyond its original or normal condition, by enlarging the pores or depressions beyond their normal state. Further, the invention resides in thus sand-blasting new woods of the cheaper grades to so accentuate their grained characteristics as to cause them to rival in appearance and beauty more expensive woods. Therefore, I wish it to be understood that While the coatings described yield a very beautiful product of a two-toned effect the invention contemplates any of the finishing steps commonly employed in the wood-finishing art, whether the coatings be lacquers, enamels, stains, fillers, varnishes, shellacs, or otherwise.

I have referred to the sand as being fine sand. I may state that as supplied to the trade for sand- In repeated paintings of the screen 4 my abandoned application Serial Number 736,030, filed March 20, 1947.

Sandblasting is an old art. It has been used on metal, stone, brick, castings, numerous other things and even on wood such as the sides of old houses where fine work was not required. However, I believe that I am the first to "tame" or adapt sand-blasting to the removal of embedded finishes from fine furniture without destroying the furniture in the process. Sandblasting is usually done at relatively high pressures. Such pressures do no damage to the side of a house, the side of a steel boat, or a plank of wood, but the results on fine furniture are different and quite considerably different when delicate carvings, turnings and extremely thin veneers and even when soft, delicately grained, solid woods are en countered. The high spots on fine, solid wood turnings will invariably be worn away and the shape distorted by high pressures, and thin veneers are often worn through. It is in such instances that my technique of pressure regulation and sand grain selection enables" me to remove firmly embedded finishes from fine furniture without damage to the wood grain, veneer, and without distortion of the shape of the furniture.

Veneers are of various thicknesses. Crossbanding or subveneers, those lying beneath the top veneer, are usually from one-twentieth inch to one-eighth inch. Such veneers are usually of cheaper grades of lumber such as poplar or gum.

blasting purposes, sand is delivered in three grades, namely fine, medium and coarse and in handling the thin and tender veneers the fine grade is used so that it will enter the small pores of the veneer grain.

This application is a continuation-in-part of However, the U. S. standard for furniture face veneers is one-twenty-eighth inch. This veneer, after scraping and sanding, is usually somewhere near one-fortieth inch. Such veneer, as may well be imagined is very easily destroyed by high pressure blasting and by coarse sand. Of course, there are instances wherein surface veneers onesixteenth inch thick are used. Such veneers after sanding are reduced to one-twentieth inch or less. Even such thicker veneer is easily destroyed by high pressures and coarse sand.

Veneers and their thicknesses are not, however, the only considerations in finish removal. In the case of carved, or plain, solid wood furniture it is possible to obtain only a rough surface with the standard blasting procedure. To obtain a smooth surface it is necessary to reduce the pressure to a point until only the finish isremoved and the wood grain remains smooth. This point of pressure varies according to the wood, the finish and the complexity of the furniture encountered.

The demand for light, bleached furniture is the rage. A great deal of fine furniture is done in very dark finishes. To refinish such furniture in light, bleached finishes in the regular manner is tedious, slow and expensive. Regardless of how well the varnish removing is done by conventional methods and without sandblasting there are still many oils, stains and resins remaining in the wood grains. When it is attempted to remove these, several applications, (two to four) of bleach must be applied and each application thoroughly brushed into the wood. Bleaches are water soluble and are slow in penetrating the wood. Even after this treatment it often happens that the recesses remain dark. In contrast to this standard procedure my technique of using low pressure blasting with fine sand easily accomplishes the removal of the old finish, slightly breaks the wood surface and enables the bleach to penetrate more deeply into the wood. Any slight abrasion of the wood from the blasting is removed by the wetting and swelling action of the v bleach. Sandpapering after drying of the wood results in a smooth surface to which is easily applied the customary procedures or wood finishing. I find one application of bleach is sufficient in my process and no dark spots remain in the recesses because the sand penetrates into the finest corners.

For most furniture finished with the standard veneers, I find pressures between 20 and 65 pounds to be the best and safest, according to the nature of the wood being treated. Pressures in the lower ranges, to wit: from 20 to 50 pounds per square inch yield clean, smooth surfaces with the varnish completely routed out. As the pressures get higher the final finish becomes progressively rougher but with the advantage that the resultant slight breaking of the surface opens the way for the bleach to get at and remove stubbon patches of deeply embedded stains. oils, resins, etc.

I claim:

1. A method of refinishing old furniture having a thin veneer surface which veneer is finished with a surface coating of varnish some of which is embedded in the pores of the wood of the veneer, which consists of projecting against said surface coating a blast of fine, dry abrasive particles and a carrier fluid at a pressure of from 20 to 65 pounds per square inch so as to remove said varnish coating from the surface of the veneer and also from the pores and limiting the application of the blast so as to avoid cutting through the veneer.

2. A method of refinishing old furniture having a thin veneer surfacing which veneer is finished with a surface coating of varnish some of which is embedded in the pores of the wood of the veneer, which consists of projecting against said surface coating a blast of fine, dry abrasive particles and air at a pressure of approximately 20 pounds per square inch so as to remove said varnish coating from the surface of the veneer and also from the pores and limiting the application of the blast so as to avoid cutting through the veneer.

3. A method of refinishing old furniture having a surface layer which is covered with a surface coating of hard varnish and filler some of which is embedded in the pores of the wood of the veneer, which method consists of projecting a blast of fine sand and air against said surface coating at such pressure and through such period of time as to remove the varnish and filler both from the surface and from the pores of the wood while limiting such pressure to not to exceed pounds to the square inch.

4. A method as recited in claim 3 wherein the application of the blast is continued to a degree to enlarge the pores of the wood and thereby accentuate the grain beyond its state when originally finished.

5. A method of refinishing grained woods which have previously had varnish and filler applied thereto to fill the pores of the wood and to bring the surface to a smooth and glossy condition, which method consists of lightly sandblasting the surface of the wood with fine sand and air at pressures of from 20 to 65 pounds per square inch through such period of time as to clean oi! the surface coating of varnish and to rout the hard varnish and filler out of the pores of the grain but without destroying the lignin which delineatesthe grain.

6. A method of refinishing grained woods which have previously had stains, varnish and filler applied thereto to fill the pores of the wood and to bring the surface to a smooth and glossy condition, which method consists of lightly sandblasting the surface of the wood with fine sand and air at 'a pressure of not to exceed 65 pounds per square inch through such period of time as to clean off the surface coating of varnish and to rout the hard varnish and filler out of the pores of the grain but without destroying the lignin which delineates the grain, the pressures employed being suflicient to slightly roughen the surface of the wood in the pores to permit the more ready penetration of a bleaching material in the removal of stubborn remaining stains.

CHARLES ROMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 446,961 Bryce Feb. 24, 1891 607,825 Burger July 26, 1898 2,345,942 Lehman Apr. 4, 1944

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