US1988450A - Finish surface and method of applying same - Google Patents

Description

Jan. 22, 1935. R, E KELLEY y 1,988,450

FINISH SURFACE AND METHOD OF APPLYING- SAME- Filed July ll, 1931 IIII' IIIIIII Z2 6' @WMM/fl@ i INVENTOR WWW/@m ATTORNEYS Patented Jan. 22, 1935 vFINISH SURFACE AND METHOD F APPLYING SAME Raymond E. Kelley, Snyder, N. Y., assigner to Helene T. Kelley, Snyder, N. Y.

Application .myI 11, 1931, serial No. 550,181

1 Claim.

This invention relates to a method of surfacing or finishing structural surfaces by mechanically applied process of permanently binding plaster, stucco or cement to concrete masonry of other structural surfaces in such a manner as to positively prevent cracking, straining or the separation of the finish from its base and also overcoming dampness and at the same time overcoming the plane o! cleavage.

The principal object of this invention is obtained by applying to the structural surface to be plastered a coat of bonding material which renders the structure damp-proof and at the same time applying with the bonding material an inert material such as grit or sand blast sand which is completely embedded and covered by the bonding material butv which forms a roughened surface forming numerous keys so that when the plaster is applied it is keyed to the structure.

It has heretofore been proposed, as outlined in the Parkin Patent, No. 1,282,460 to apply to the masonry surface a. coating of cold asphalt or other binding material and after such coating applied to blow against the coating a blast of sand or gravel, the sand sticking to the asphalt and forming numerous `keys for the plaster which is subsequently applied. After such a surface has been applied, however, the weakness of the bond between the stone and the asphalt is readily made apparent when the surface is scraped with a stick or the like, the inert sand or gravel readily rubbing off and leaving the asphalt surface exposed. This weakness of the bond between the inert and the bonding material continues after the plaster is applied and forms a plane of cleavage which is relatively weak so that the plaster in time cracks andy breaks away. Moreover, in applying the sand or gravel to a ceiling very little of the sand or gravel sticks to the asphalt coat- 4 ing so that in ceilings not only is there a weak bond between the sand or gravel and the asphalt but also there is a much smaller amount of sand or gravel to form keys for the plaster.

The present invention relates primarily to the improvement of the bond between the inert and the asphalt and is achieved by applying the asphalt and sand or gravel at the same time and in such manner that the sand or gravel is completely embedded in the asphalt and not merely stuck to it and at the same time the sand or gravel is large enough so as to form keys for the plaster. By this means the weak plane of cleavage between the asphalt and the sand or gravel is eliminated without in any way sacrificing the strength of surface to the upper face of which it is desired to apply a coating of plaster, stucco or the like. 10

Fig. 2 is a similar viewshowing a coating of asphalt and gravel applied thereto, the gravel being completely embedded and forming keys for the subsequent application of the plaster.

Fig. 3 is a similar view showing the plaster ap- 15 plied to the coating.

Fig. 4 is a longitudinal section through a gun suitable for use in simultaneously applying asphalt and an inert substance in accordance with the invention.

Fig. 5 is a longitudinal section taken at right angles to Fig. 4.

In Fig. 1 is illustrated a concrete or masonry structure 10 although itwill be understood that the invention can be carried out with any kind 25 of a body or surface to which asphalt or other similar bonding material will adhere. In apply- .ing plaster or stucco to such a body the first step,

in accordance .with thepresent invention, is to apply simultaneously a coating of cold asphalt 11 3o and sand or gravel 12. These two materials are applied simultaneously and preferably by means of a suitable gun, such as is shown in Figs. 4 and 5.

This gun comprises a head 13 having an exter- '35 nally threaded nipple 14 and an internal hollow stem 15, the tapered outer end 16 of which projects out through the nipple 14. On one side of the head another nipple 17 is provided which connects with an air line 18, a passage 19 leading 4o from this air line to the internal passage 20 of the stem l5. 0n the opposite side of the body another nipple 21 is provided which communicates with the interior of the nipple 14 and also connects with a line 22 supplying cold asphalt. 45 Over the outlet nipple 14 a cap or nozzle 23 is screwed. this nozzle having an opening 24 through which the tapered end of the stem 1511s adapted to project. It is apparent that the air issuing from the hollow stem 15 will draw out the bond- 50 ing material and spray it upon the surface toward which the gun is pointed and that by screwing the nozzle 23 backwards or forwards the amount of bonding material can be increased or reduced as desired. Formed integrally with the nozzle 23 is an inclined sleeve 25 which is adapted to receive a sand supply line 26, this sand supply line being directed toward the center of the stream of air and bonding material issuing from the nozzle 23. The sand or gravel is applied under pressure and since all three streams are sprayed upon the surface at the same time the gravel or coarse sandlis'completely embedded in the asphalt and all sides of each piece of sand or gravel is completely embedded in the asphalt, as best shown in Fig. 2. By this means a strong bond is obtained between the inert and the asphalt and since the asphalt adheres with great strength to the concrete or masonry surface a strong bond is obtained between the inert and the concrete or masonry structure.

From twenty to forty pounds of sand (this being from .20 to .44 cubic feet, based on the weight of sand as 100 lbs. per cubic foot in Machinery's Handbook, sixth edition, and 90 lbs. per cubic foot given in Kents Mechanical Engineers Handbook, tenth edition); to one gallon of asphalt can be applied but preferably approximately one gallon of asphalt is appliedto each thirty pounds of sand (.30 to .33 cubic feet) and it will therefore be apparent that the coating around each piece of sand or gravel is'relativelythin and that therefore the sand or gravel and asphalt surface' so applied is very rough; and forms numerous irregular keys or undercut indentations on its surface. This undercut, irregular. rough surface forms an excellent key and supportx for the coating of plaster 27 which issubsequently applied, the plaster entering into the keyways and undercut indentations formed by the coated rough sand particles and being firmly united thereto. After the rst and second (scratch and brown) coats of plaster have set a finishing coat 28 can be applied to the scratch and brown coat of plaster in the usual and well known manner.

From the foregoing it is apparent that a strong bond is obtained between the asphalt and the concrete or masonry structural surface to which it is applied, a strong bond is obtained between the sand or gravel and the asphalt since the sand or gravel is completely embedded in the asphalt and at the same time the sand or gravel forms a very rough and irregular surface which has numerous undercut indentations so that when the plaster coating is applied it is firmly keyed to the sand or gravel and asphalt coating thereby eliminating the plane of cleavage between the coating and the plaster.

I am aware that coarse sand or gravel and cold asphalt have been applied separately to a structural surface, as previously described, without resulting disadvantage of a Weak plane of cleavage between the sand or gravel and the asphalt. The present invention therefore comprehends the simultaneous application and embedding of sand or gravel in a coating of asphalt in such manner that the sand or gravel is completely embedded and at the same time forms a roughened key surface to which a plaster coating will be firmly bonded.

I claim as my invention:

The methodI of finishing and coating a structural surface which consists in simultaneously forcing a spray of a relatively small amount of asphalt and a stream of a relatively large amount of coarse sand against said surface, said materials being applied in proportions of one gallon of asf phalt to. from .20- to .44 cubic feet of sand, said stream mingling and said sand being coated with said asphalt while in the air and before reaching said surface and said asphalt forming 4a. coating on said surface and also causing the adhesion of the pieces of sand to said surface and providing voids between the grains of sand of suiilcent size to form a key or clutch for the reception of a plastic coating and subsequently applying a plastic coating thereto.

RAYMOND E. KELLEY.

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