US1920486A - Pickling vat and coating therefor - Google Patents

Description

Aug. l, 1933. w.; sMi-rh 1,920,486

PICKLING VAT AND COATING THEREFOR Filed'Nov.- 29. 1929 lNvENToR BY M /q Afm /A ATTORNEY Patented ug'. 1, 1933 PATEN'il OFFICE PICKLING VA'll` AND COATING THEREFOR William E. Smith, Lakewood, Ohio Application November 29, 1929. Serial No. 410,424

5 Claims.

My invention is an improvement in protective coating compositions and in the method of applying the same.

In pickling steel or other metals it is the common practice to place the parts in a vat or tank containing a bath of suitable material, such as sulphuric, muriatic and nitric acids, ammonia, oil, etc. Such tubs or vats areusually formed of wood, steel or concrete, and heretofore great difficultyA has been experienced in protecting the materials of the vat against charring, corrosion,

, or other destructive reactions. Lam aware that faces of the vat material are protected from conattempts have been made heretofore to protect the vats by coating the same with certain materials, but as far as I am aware, such attempts have not been successful to the extent of completely protecting the inner surfaces of the vat material. Furthermore, I have found that the coating compositions are exposed to contact with the pickling bath, resulting in chemical reaction between the coating and bath, and deterioration of the coating.

It is one of the objects of my invention, therefore, to overcome and eliminate the disadvantages and diinculties heretofore encountered, by applying a protective coating to a vat or other container in such a manner that the inner surtact with `the pickling bath.

Another object of my invention is to prevent injury to the protective composition or coating, due to contact with the pickling solution or with objects placed in the vat.

A further object of my invention is to enable leaky tanks or vats to be repaired by applying my protective composition in a plastic state, as, for instance, in wooden tanks lined with lead which have become punctured or damaged.

Another object of the invention is to provide a composition of matter resistant-to corrosion and active chemical reaction with a pickling bath, and which is capable of being applied to a surface in a plastic state, the exposed surface of the composition forming a protective and material supporting crust.

Other objects and advantages of my invention will become more apparent from the following description of an embodiment thereof, reference being made to the accompanying drawing in which like reference characters are employed to tion.

Fig. 2 is a broken section of a Wooden tank or vat illustrating the method of applying the protective coating.

By the use of my invention, tanks or vats of Wood, concrete or steel may be effectively protected from corrosion, injury and leakage, due to the chemical action of the pickling fluids contained in such vats or tanks. By the use of my invention the useful life of old containers may be increased indefinitely, by patching punctured portions of the usual lead lining with a material made in accordance with my invention. The lead lining of old vats may also be entirely removed and a coating of my composition applied in accordance with my invention.

I prefer to employ a composition of matter which is resistant to acids and alkalis used in pickling and plating baths, and which may be applied by means of a trowel or brush to form a smooth homogeneous coating or lining. I also prefer to employ such a composition which will dry quickly to touch and which will form an outer supporting crust.

I have discovered that the following composition of matter gives excellent results and possesses the above mentioned desirable characteristics.

The composition consists of approximately 45% pigment and 55% vehicle thoroughly and intimately mixed at ordinary atmospheric temperatures by means of suitable mechanical mixers. The pigment preferably consists of asbestos fibre, aluminum silicate, and barium spulphate in the proper proportions to produce a troweling consistency when mixed with the vehicle in the above approximate proportions. In making the pigment I find the following proportions quite satisfactory:

Parts. Asbestos fibre 28 Aluminum silicate 44 Barium sulphate 28 77 Fahrenheit. It should, for best results have a hardness of zero with a needle penetrometer at the same temperature. y

In the use of petroleum asphalt, I prefer to use av blown product having a specic gravity at 77 Fahrenheit of from .90 to 1.07 and a fusing point (ball and ring method) of 200 to 250 Fahrenheit. The stearine pitch employed should, for best re. suits, have a specific gravity of .90 to 1.10 at 77 Fahrenheit.

As stated above, I prefer to mix the vehicle andpigment in the ratio of 55 to 45, thoroughly and intimately mixed by suitable mechanical mixers, whereby a complete amalgamation of the ingredients at ordinary temperatures is readily accomplished. The composition of matter thus formed is quick drying and is acid and alkali resistant, being of such consistency as to enable its application with a trovvel or brush.

Referring now to the drawing, in Fig. l I'have illustrated the manner of applying the composition to a concrete tank or vat l. The composition is applied in the form of a coating 2 of suitable thickness. The coating is applied directly to the inner Walls of the concrete vat or in conjunction with a lining of sulphur, which is commonly used in concrete pickling vats. After the protective coating has been applied and has dried sufficiently to form an outer supporting crust, the vat is lined with planks 3 preferably closely tted by tongue and groove. It is to be noted, in itting the planks in place, that, in the event the crust of the coating is punctured, a new crust willv be formed over 'the exposed portion of the compound.

By covering the coating with closely itted boards the coating is prevented from coming into direct contact with the pickling or plating solution, and is protected from injury or puncture by objects placed in the vat. It will be noted that the coating preferably extends over the entire inner surface of the vat. Cap plates 4 may be fitted along the upper edges of the vat to hold the side boards in place. v

In Fig. 2 I have illustrated in cross section -a 5 wooden tank having a base 5 and side walls 6. The

coating is applied as inthe case of the concrete tank, to the entire inner surface of the tank and is indicated at 2. In Wooden tanks already is use and which are lined with a coating of lead as is the usual practice, the protective coating may be applied directly to the lead coating, or if desired, punctures in the lead lining may be patched with the protective coating. In either case planks or boards 3 may be fitted over the coating as shown in Fig. 2, the boards being closely tted preferably by the tongue and groove method. The boards 3 may be secured in place by strong copper'nails driven through the boards, and coating and into the tank body. A strip '7 may be applied along the upper edges of the tank and secured in place by the nails 8.

My invention is not limited in its application to pickling tanks but may also be used in connection with water tanks or other containers in which thereon, and a layer of brous material supported non-acid or non-alkali solutions are deposited. In such use the planks or boards 3 may be eliminated and the coating exposed to the liquid deposited in the receptacle.

Although I have not illustrated a steel tank in the drawing, it is obvious that my invention may be suitably applied to such tanks. In this instance the protective coating may be thinned and applied with a brush, two or three coatings being sufficient to prevent contact of the steel and pickling solution and corrosion of the steel due to such contact. If desired, the coating so applied may be protected against injury from objects moving in the tank, by'a board lining as described in connection with Figs. I and 2.

It will be noted that by `my invention I have provided. a protective coating composition for tanks, vats and other containers, which is capable of resisting the attack of acid and alkali solutions, and which dries quickly upon application, forining a protective and supporting crust. By my invention the useful life oi tanks, etc. is materially increased and the coating is protected against injury or puncture by objects rnoving in the tank.

I do not intend to limit myself to the form of rny invention shown or described herein, since various changes may be rnade Without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. A pickling vat having a bottom and side Walls, an acid resisting coating applied to the inner surfaces of the Vat, said coating having the property of forming an outer material supporting crust, the inner portion of the coating being plas- 1m tic, and a layer of fibrous material supported on said crust. n t

2.l A vat comprising bottom and side walls, and a corrosion resisting layer applied in aplastic condition to the inner surfaces of said Walls, said coating having the property of forming a crust on its outer surface for supporting materials thereon.

3. A vat comprising bottom and side walls, and a corrosion resisting layer applied in a plastic condition to the inner surfaces of said Walls, said coating having the property of forming a crust on its outer surface for supporting materials on said crust.

4. A container, and a lining of acid and alkali resistant material intimately applied to the inner surfaces of the container, said material having a hard outer surface and an inner portion in a substantially plastic condition.

5. A container, and a lining of acid and alkali resistant material intimately applied to the inner surfaces of the container, said material having a hard outer surface and an inner portion in a substantially plastic condition, and a layer of brous material superimposed on said lining and comprising a plurality of wooden members closely tted together.

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