US2231233A - Process of finishing materials - Google Patents

Description

Feb. 11, 1941. H. ViENHAUS PROCESS OF FINISHING MATERIALS Filed July 14, 1939 ROUGH CASTING w m mm Rm. mww G A mum 5E AMN N mmw 6-...

APPLY BRUSH coAT 0F 11 FREE sanome GLAZEAND DRY FOR TWO HOURS.

m smoo'rH wn'u FELT PAD SOAKEDIN LACQUER CLEANER.

APPLY comma or FREE 11 SANDING GLAZE WITH KNIFE OR BLADE.

Y SMOOTH WITH FELT PAD AS lN STEPIII.

SMOOTH SURFACE WITH SAND PAPER.

MI APPLY SPRAY conr 0F SEALER AND fHR'DRY FOR ZOMINUTES:

APPLY FINISH COATOF LACQUER ENAMEL SHJI .fwuvwob HENRY VIENHAUS (BY p Patented Feb. 11, 1941 UNITED STATES PATENT OFFICE PROCESS OF FINISHING MATERIALS Henry Vienhaus, Springfield, Ohio Application July 14, 1939, Serial No. 284,520

2 Claims- (CI. 91-68) My invention relates to a process of finishing articles and more particularly to an improved process of finishing metal articles such as castings, press sheet metal parts, machine tools and 5 similar materials having metal surfaces. While my process is especially adapted for the finishing of metal surfaces, it is to be understood that the process is also applicable to the finishing of wood, glas and the like articles.

It has heretofore been conventional practice to finish articles of this character with a lacquer or paint composition after the surface has been prepared by the application of primer and sand ing surface coatings to provide a base coating which will tenaciously adhere to the metal sur face and an intermediate coating which is adapted to present a smooth adherent film to which the finishing coat applied thereover will adhere.

In the prior processes, however, a great deal of time and labor are required in performing the sanding operations. Further; it is nec s arvto allow an appreciable lapse of time vbetween the sanding operations in order tov producea satisfactory -finish. Aside fr0m this,,heretofore no; p v s on. made n; t fl e lw s for-- producing ,an oil-resistant mealtim coatin so e ma catthi Contact W t o r s 1 p ir o etc" th finishing, lacquer coat willladheresatisfawl y- In he s l t dn arti le w t he conventional lacquer coating compositions v the sanded under-coat surfaces considerable porosity and readily absorb oleaginous substances, and the like which, have not been removed before the application of additional coatingsorthefinallacquercoatwillresultin producing a film having poor adhesion and consequently of unsatisfactory durability.

It is an object of this invention to provide provided with a durable finish in much less time and atmateiiallylesslaborcost ascompared with prior methods.

Another object is to provide a process of finingmachinepartssothatthesurfacefilmof the built-up coatings is oil-resistant and exhibits less porosity. v

Afm'therobjectofthlsinventionistosubstantially eliminate the labor and time involved in sanding the intermediate coatings in the finishing of articles.

Another object is to provide a method of treating the various coating film surfaces so that the outermost portion of the film surface is 5 made to consolidate to produce a very hard, substantially non-porous, uniformly smooth surface which is oilresistant.

The accompanying drawing illustrates diagrammatically the several steps of my process T of finishing metal castings. I have illustrated the difl'erent steps in connection with the finishing of a metal casting. However, it will be appreciated that my process is applicable for finishing various types of articles which may be made of any suitable material such as wood, paper, metal, glass, ceramic materiaLfetc.

As shown in the drawing thevarioussteps to be performed in finishing a rough metal casting by my improved process comprise the follow- 20 1 Step I.-'1he surface of the casting to be finished is ground to provide a with -a suitable wheel or mechanism.

In .this mannerall =protuberances, fins, 25

sandon the surface of the metal are ved... I 1 1 Step en t o n surfac o the -1 ing is applied a free sanding glaae material which is allowed to dry fromfi e to two hours. 30 This glaze coating may be of the, brush or spray type and may belaid down in one or more coats. Preferably a brush coating is applied. Conventional sanding primer glazes may be employed in practicing my invention. As an example of 35 a free sanding glaze composition the following typical formula is given:

Free sanding glaze lbs. whiting 45 lbs. barytes '18 lbs. pigment ground 35 lbs. lithopone lb. carbon black 36 lbs. blown castor oil 30 lbs. xylol paste comprising gala'raw castor oil 45 l5 gals. butanol 20 gals. butyl acetate 10 gals. shellac varnishngg fi shellac A suitable lacquer thinner applicable for mixing with the above glaze so as to vary the consistency as desired for applicationby brushing or spraying is as follows:

Sanding glaze thinner Gallons Toluol or xylol 20 Butanol or alcohol 10 Butyl acetate or amyl acetate 18 Step III .-After the free sanding glaze coating has been applied and allowed to dry the coating surface is smoothed over with a felt pad, or suitable absorbent material, soaked in a special lacquer cleaner composition having the property of producing a hard, uniform, smooth film surface which is substantially resistant to oil, grease, finger marks and the like. The lacquer thinner employed in this instance is a composition that will function to slightly soften the outer film surface of the coating during its application but will evaporate before it has fully penetrated the coating film. In this way the outer film surface is made to flow together producing a denser surface film which dries to a hard, uniformly smooth non-porous, oil-resistant surface.

As an example of a lacquer thinner composition which may be employed for this purpose the following is given:

LACQUER CLEANER Example 1 Per cent Acetone (by volume) 90 to 95 Triphenyl phosphate (by volume) 5 to 10 In some instances acetone may be used alone if the conditions of application are such that solvent will not evaporate too rapidly. In place of acetone other substances such as alcohol, ether, or similar lacquer solvents, may be used. Likewise phenyl phosphate, tricresyl phosphate, dibutyl phthalate or equivalent materials may be optionally employed in place of triphenyl phosg Another example of a suitable lacquercleaner may comprise the following formula:

LAc UnR CLEANER Example 2 a Gallons (V. M. P.) Petroleum naphtha or turpentine- 11 Toluol or xylol 7 Denatured alcohol 7 Y Acetone 7 used in step II which in its natural state is of a consistency of putty. This glaze coating may be applied with a knife, blade or other suitable implement. In some instances the glaze may be applied in the form of a spray. Preferably, however, it is applied as a knife glaze. Since the glaze putty comprises only a small amount of I solvent no drying time is necessary as it dries to a smooth surface immediately after application.

Step

V.After applying the glaze putty the film surface is smoothed over with the felt pad soaked in lacquer thinner as in step III.

Step VI.-In this step the treated glaze surface is sanded smooth to remove any imperfections with sandpaper. For this purpose a fine grit sandpaper, on the order of 120 or finer, may be used.

Step VII.When the surface has been sanded smooth in the previous operation the coating is then ready for the application of a sealer or surfacer, which may be of the air drying type, preparatory to the application of the finish lacquer or enamel coat. A typical example of the formulation of the lacquer surfacer which may be used is as follows:

Lacquer surfacer Lithopone lbs 300 Slate flour pigment do 300 Barytes do 250 Carbon black d0 10 Bentonite do Raw caster oil; ga1s 14 Tricresyl phosphate do 10 Ethyl acetate do 10 D'ewaxed dammar solution do 14 Toluol do. 14

The above materials are suitably ground on a mill and incorporated with a nitrocellulose solution comprising:

/2-sec. nitrocellulose cotton lbs 200 20-sec. cellulose cotton do 50 Toluol gals 15 Butanol do 5 Butyl acetate do 15 Ethyl acetate do 10 The above ingredients are mixed together to form a homogeneous lacquer surfacer composition which is sprayed onto the sanded surface coating and allowed to air dry for approximately twentyv minutes. This surfacer composition forms a seal over theunder-coating and provides a tooth base upon which the final lacquer coat-. ing composition may be applied so as to produce a thoroughly adherent coating. Step .VIII.-O.ver the surfacer is applied the finishing coat'of. lacquer enamel of any desired composition whichwill adhere to the surfacer and dry to a hard, smooth durable finish.

[As an example of a finishing lacquer coating composition which is of gray color, the following is illustrative:

Finishing lacquer 705 lbs. lithopone 50 lbs. of a composition 235 lbs. zinc oxide comprising 150 lbs. blown castor oil 150 lbs. xylol or benzol 10 lbs. carbon black 12 ms. U1 a carbon black 50 lbs. dammar (dewaxcd) ground paste comprisgum ing 37% lbs. blown oastor oil 37% lbs. dibutyl phthalate 128 lbs. iron oxide lbs. blown castor oil 50 lbs. toluol or benzol 104 lbs. %-sec. nitrocellulose cotton 76 lbs. 4-sec. nitrocellulose cotton 35 lbs. dibutyl plithalato 13% gals. toluol 5 gals. xylol 15 gals. butanol 6% als. ethyl acetate 30$fgals. butyl acetate 14 gals. dewaxed dammar gum 8 lbs. ground paste comprising 64 gals. of a nitrocellulose lacquer comprising 48 lbs. y -sec. nitrocellulose cotton 60 lbs. 4-sec. nitrocellulose cotton 22 gals. carbon black ground paste, supra 4}2 gals. dammar gum (dcwaxed) 3 gals. of a mixture comprising 4 lbs. of ester gum and 1 gal. toluol 1V gals. benzol 4% gals. ethyl ,acetate 11% gals. butyl acetate 20% gals. toluol 4% gals. butanol 3% gals. dibutyl phthalate It will be understood that the above compositions are merely illustrative of the type of coatings to be used and it is to be understood that the process is also adapted for use in connection with oil type glazes, putties and surfacers as well as nitrocellulose base compositions.

It is a particular feature of my invention that, by finishing articles of the method herein described, a satisfactory under-coating system may be rapidly built up and a finishing lacquer coat applied thereover so as to produce a finish that is adherent, flexible and durable.

Further it is desired to be understood that widely different embodiments of the compositions may be made in following my improved process without departing from the spirit and scope thereof; and that this invention is not limited to the specific details of the process and compositions except as defined in the appended claims.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The process of finishing rough metal cast- 12 gals. of a composition comprising ings consisting in the steps of (a) grinding oif the surface to remove foreign matter and protuberances thereon, (b) applying thereover a coating consisting of a lacquer sanding glaze and drying, (c) smoothing the surface film thereof by rubbing only with a pad soaked in lacquer solvent thinner which is a solvent for the film former of the coating, (d) applying thereover a lacquer sanding glaze composition in the form of a putty, (e) smoothing the surface thereof by rubbing only with a pad containing lacquer solvent thinner, said lacquer solvent being a solvent for the binder of said putty, and after evaporation of said lacquer solvent rubbing the surface over with fine sandpaper, (j) applying thereover a spray coating of lacquer surfacer composition adapted to fill and seal the imperfections in the previous coating, and finally (g) applying thereover a finishing coat of lacquer enamel.

2. The process of finishing castings with lacquer coating compositions comprising the steps of: (a) grinding off the surface to remove imperfections on the surface thereover, (b) applying a lacquer sanding glaze coating over said ground thereover a coating of said sanding glaze having I a consistency of putty, and (e) smoothing the surface thereof by rubbing only with a pad soaked in solvent thinner which thinner softens the outer film surface, (I) rubbing the surface over with fine sand paper and applying a coating thereover to seal the same, and (g) finally applying a finish coat of lacquer enamel.

HENRY VIENHAUS.

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