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Manual of Painting Outside Cover



Manual of Painting Outside Cove









  This manual has been prepared for distribution to vessels for general information relative to the source, use, and efficiency of paint and the raw materials from which paint is manufactured. It is also desired to present information relative to the preparation of surfaces to be painted, the application of paints, and the care of mixed paints and paintbrushes, in a form that will be readily available for the use of first lieutenants of vessels, painters in the Navy, and others concerned.
  The formulas for the paints used on naval vessels, together with instructions for their procurement and use, are contained^ in "Paint-ing and Cementing Vessels, General Specifications, Appendix 6," obtainable from Bureau of Construction and Repair, Navy De-partment.
  Much of the information and many of the definitions contained in this manual are taken from other publications.













Principal white pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
     (a) White lead (basic carbonate) . . . . . . . . . . . . . . . . . . . . . . . 1
     (b) Sublimed white lead or basic sulphate of white lead . . . . . . . . . . . 2
     (c) Zinc oxide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
     (d) Leaded zinc oxide . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
     (e) Titanium oxide pigment . . . . . . . . . . . . . . . . . . . . . . . . . . 3
     (f) Lithopone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
     (g) Inerts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Principal color pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
     (a) Natural earth pigments . . . . . . . . . . . . . . . . . . . . . . . . . . 3
     (b) Chemical colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
     (c) Carbon blacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4


Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Oils, drying and semidrying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
     Linseed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
     Poppy-seed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
     China-wood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
     Menhaden fish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
     Cottonseed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
     Corn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
     Soy-bean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Varnishes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Volatile thinners, general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
     Turpentine, gum spirits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
     Turpentine, wood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
     Mineral spirits (turpentine substitute) . . . . . . . . . . . . . . . . . . . . . . 7
     Benzol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
     Toluol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
     Coal-tar naphtha . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
     Alcohol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Driers, general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7


Ready-mixed paint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Settling of pigments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Prevention of settling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Value of thorough mixing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9


Preparation of surfaces to be painted . . . . . . . . . . . . . . . . . . . . . . . . . 11


Application of paint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12


Care of mixed paint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13










Brushes and how to care for them . . . . . . . . . . . . . . . . . . . . . . . . . 14
    Different types used on board ship . . . . . . . . . . . . . . . . . . . . . . 14
    How to prevent bristles from falling out of brush . . . . . . . . . . . . . . . 14
    How to properly clean a brush . . . . . . . . . . . . . . . . . . . . . . . . . 14
    Binding of brushes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15


Varnishes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16


Bituminous compositions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
    Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
    Nature of material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
    Notes on the use of bituminous compositions . . . . . . . . . . . . . . . . . . 17


Bottom paints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
    Kind used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
    Object of anticorrosive paint . . . . . . . . . . . . . . . . . . . . . . . . . 18
    Object of antifouling paint . . . . . . . . . . . . . . . . . . . . . . . . . . 18
    Preparation of surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
    Application of anticorrosive paint . . . . . . . . . . . . . . . . . . . . . . . 18
    Application of antifouling paint . . . . . . . . . . . . . . . . . . . . . . . . 19


A few "don'ts" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20


Poisonous effects produced by paints and their prevention . . . . . . . . . . . . . 21















  * Paint is a mixture of pigment with vehicle, intended to be spread in thin coats for decoration or protection, or both.
  According to this definition, a mixture of pigment and varnish is a paint, and on the other hand, a solution of stains in oil or varnish, no pigment being present, is not a paint.
  * Pigment.-The fine solid particles used in the preparation of paint and substantially insoluble in the vehicle.
  Asphaltic materials are not pigments except when they contain substances substantially insoluble in the vehicle in which they are used.
  The pigments used in paint manufacture may be divided into (a) white bases, (b) inerts, (c) natural earth colors, (d) chemical colors, (e) lakes, etc.
  * Vehicle.—The liquid portion of a paint.
  Here anything that is dissolved in the liquid portion of a paint is a part of the vehicle.
  The vehicles used in paints may be divided into (a) drying oils, (b) semidrying oils, (c) varnishes, (d) volatile thinners, (e) driers.

   NOTE.-Definitions marked with the asterisk (o) are quoted from "Standard definitions of terms relating to paint specifications," A. S. T. M. (1924), pp. 876-880.








Chapter 1


  The most important white pigments are white lead, zinc oxide, basic sulphate of lead, lithophone, titanium oxide pigment, and certain inert pigments, such as barytes, asbestine, silica, etc.

  White lead (basic carbonate) is a compound of metallic lead with carbonic acid gas, oxygen, and water. It is manufactured by a number of processes, the two most important of which are the well-known "old Dutch process" and the more modern "cylinder" or "quick process." White lead made by either process is acceptable to the Navy Department under the standard specifications for white lead.
  In the "old Dutch process" metallic lead is melted and cast into perforated disks, called buckles. These buckles, which are about 6 inches in diameter, are placed into pots containing about 1 pint of dilute acetic acid (vinegar). The pots are placed in rooms, in tiers or layers, 600 to 1,000 pots to each tier. They are covered with boards and layers of tanbark are placed between tiers. The rooms, known as "stacks," are kept closed for three or four months, during which period the heat and carbonic acid gas generated by fermentation of the tanbark, together with the acid vapors, combine to corrode the lead more or less completely into a white flaky substance (basic lead carbonate).
  This white substance after it is crushed, screened, floated, ground in water, and dried forms the white lead of commerce, and is either sold in the dry state to paint and color manufacturers or ground in linseed oil and sold in this form for general painting purposes.
  In the "cylinder" or "quick process" method melted lead is blown into fine granules by means of a jet of superheated steam. This powdered lead is charged into large slowly revolving wooden cylin-ders or drums, moistened with dilute acetic acid, and subjected for several days to the action of air and carbonic acid derived from burning coke. The subsequent procedure resembles closely the: methods of the old Dutch process.
  White lead is a useful and valuable pigment on account of its opacity and working qualities. Paint containing white lead as the sole pigment is subject to somewhat rapid disintegration. Though the durability of such a paint may be from three to five years, it will, in the meantime, have begun to disintegrate on the surface and wear off in the form of a fine- powder ("chalking"). This type of disintegration, if not allowed to proceed too far, has the advantage




of affording a surface requiring little preparation preparatory to repamting
  White-lead paint is apt to lose its original whiteness, being dark-ened by the action of sulphur compounds contained in tho, atmosphere.

  This product is so named because it is obtained from Galena a lead sulphide ore, by a sublimation process. The ore is mined crushed, concentrated by removing associated rock, etc., and roasted' The fumes arising from the roasted ore unite with the oxygen in the air and form a white powder, basic lead sulphate, which does not require grinding.
  Sublimed white lead exceeds in the fineness of the particles the ordinary grades of white lead (basic carbonate), and is considered equal to them in whiteness, body, covering power, and wearing quali-ties. It differs from basic carbonate white lead in that it resists to a much greater degree the blackening action of the sulphur compounds of sewer gas and of fuel gas.

  Zinc oxide, as its name implies, is a compound of zinc and oxygen. It is produced by two methods, one known as the "French process" and the other as the "American process."
  In the American process zinc ores, such as franklinite and zincite, mixed with finely powdered anthracite, are roasted in a closed furnace having perforated grate bars. The resulting zinc oxide, after being blown through a series of cooling flues, is collected in fabric bags.
  In the French process metallic zinc, known as spelter, is roasted in a current of air, and the product of combustion-zinc oxide-is collected in closed chambers.
  Zinc oxide being a fume product is extremely fine. It is among the whitest of the so-called white pigments. French process zinc oxide is more nearly pure white than the American process pigments. It costs more, however, and should be used only in paints where whiteness is of special importance. It is unaffected in color by any gases present in the atmosphere, has no effect upon any pigment with which it may be mixed, and is nonpoisonous.
  Zinc oxide, when used alone, produces a paint of extreme hardness. Owing to the hardness of the film it is less resistant to temperature changes than is the film of a white lead paint. Zinc oxide is used to advantage in the white enamels and in combination with white lead and various other pigments in paints for general use.

  Leaded zinc oxide is prepared from ores obtained in Missouri, Kansas, Colorado, and Wisconsin in the same manner as American process zinc oxide, the essential difference being in the character of the ores used, which contain variable amounts of lead sulphide. In the process of manufacture the lead sulphide is converted into basic lead sulphate (sublimed white lead) and intimately mixed with the zinc oxides.



  Titanium oxide pigment of the grade used in Navy paints is corn-nosed of approximately 25 per cent titanium oxide coalesced with 75 oer cent blanc fixe (precipitated barium sulphate). It is of a high degree of whiteness, highly inert, and has good hiding properties. Paints made with titanium oxide pigment have exhibited a tendency to chalk, and for this reason it is commonly used in combination with other pigments, such as zinc oxide.

  Lithopone is essentially a combination of zinc sulphide and barium sulphate (blanc fixe or "permanent white"). It is very fine, white, and amorphous, and, if properly made, has excellent body and valuable properties as a pigment.
  The peculiar tendency of the earlier grades of lithopone to darken in sunlight and recover their whiteness in the dark has been largely overcome by improved methods of manufacture. Grades which are very satisfactory as regards fastness to the light are now available. As a paint pigment lithopone is best suited for interior use in wall finishes and enamels.

  In the strictest sense an inert pigment is one which does not react with any other constituent of the paint in which it is used. Commonly the term is applied to certain white or colorless pigments added to paints for various purposes, such as to form the base on which staining colors are precipitated (as in lake colors), to decrease the amount of chemically active pigments in the paint, to limit spreading power and thus increase the thickness of the paint film, to give "tooth," to prevent or retard settling and caking in the containers, etc. Some pigments, though chemically inert, are not classed among the inert or reinforcing pigments because of their importance in other respects. Among these are lampblack, graphite, carbon black, etc.
  Some of the more important inert pigments in common use are:
  Barium sulphate (barytes, blanc fixe, permanent white').
  Silica (silex, siliceous earth).
  Magnesium silicate (asbestos, asbestine, talc).
  Aluminum silicate (china clay, kaolin).
  Calcium sulphate (gypsum, terra alba).
  Calcium carbonate (white mineral primer, Paris white, whiting, etc.).
  These pigments are inert in that they are, broadly speaking, chem-ically stable and do not affect color nor destroy the life of the vehicle.

  Color pigments are used in conjunction with white base pigments, to produce any desired shade or color. They are also used alone with the necessary vehicles. They may be divided into the following classes, based on the methods of manufacture, viz:
  Natural earth colors.-These are found as deposits in the earth and utilized as pigments either in their natural state, after grinding and purification, or after further treatment, such as oxidation by burning, calcination, etc. Some of the colors are Indian red, ochre, metallic brown, siennas, umbers, mineral blacks.

  458066 O - 42 -2



  Chemical colors.—Chemical colors are pigments produced bv chemical action of one substance, usually in solution, upon another substance, resulting in the formation of a colored compound. Some of the chemical colors are: Prussian and Chinese blue, chrome yel low, chrome green, ultramarine blue, cobalt blue, vermilion and" orange mineral.
  Blacks.-The blacks comprise (a) lampblack, which is a specially prepared soot from oil lamps; (6) gas blacks, from natural gas-(c) graphite, which was originally a natural product, but which now may also be produced by means of the electric furnace; (d) bone black, ivory black, drop black, vine black, etc., made by carbonizing animal and vegetable substances. With the exception of those named under (d), the above blacks are practically pure carbons.
  The blacks have enormous covering capacity in proportion to their weight. Their durability and tinting power are good. They are used alone as pure colors, also ground with other pigments.




















Chapter 2


  Vehicles may be subdivided as follows:
     Drying oils—
        Linseed oil
        Poppy-seed oil.
        China-wood oil.
        Menhaden or fish oil.
     Semidrying oils—
        Cottonseed oil.
        Corn oil.
        Soy-bean oil.
   Volatile thinners:
     Turpentine (pure gum spirits).
     Wood turpentine.
     Mineral spirits (turpentine substitute, petroleum spirits).
     Coal-tar naphtha.

  Oils are divided into "drying," "semidrying," and "nondrying" oils. Drying oils have the property of absorbing oxygen and forming a tough elastic film. Semidrying oils possess this property in a less degree, and for this reason are not used as extensively as the drying oils. The Navy Department does not use semidrying or non-drying oils in its paints. Oils are used in paint to give it the necessary fluidity, to insure the uniform distribution of pigment on the painted surface, to form a firmly adherent and coherent film, and to impart to the paint the desired luster.
  Linseed oil.—Linseed oil is generally used to form the nonvolatile part of the vehicle. It is extracted from the seed of the flax plant. The seed is first ground, then subjected to steam heat, and the oil extracted by means of a hydraulic press. The oil after this treatment contains various foreign substances called "foots." These 'foots" are removed by settling or filtration. As storage has the effect of settling the "foots," linseed oil should not be unnecessarily shaken up just prior to its introduction into the paint. The oil accepted by the Navy Department is practically free from "foots";




but it is good practice, in spite of this fact, not to shake up the oil any more than is absolutely necessary.
  Poppy-seed oil.—Poppy-seed oil is obtained from the seed of the poppy plant. It is nearly colorless and very clear and is for this reason very desirable for use in white paints and enamels. Its price being very high, it is only used in the more expensive paints and in artists' colors. The Navy Department does not use it.
  China-wood oil.—China-wood oil, or tung oil, as it is sometimes called, is the oil obtained by heating and crushing the nuts of tung trees, which grow in China and Japan. This oil, when properly treated, will dry to a clear waterproof elastic film. It is now used quite extensively in waterproof varnishes and paints. The Navy Department does not use this oil in paints, but permits its use in some of the varnishes. It possesses one objectionable feature when ued in varnishes, i. e., it causes the varnish to thicken to a jellylike mass if the latter is left exposed to the air. It is because of this property of tung oil that waterproof varnishes should be kept in absolutely air-tight containers.
  Menhaden or fish oil.—This oil is obtained by steaming and pressing menhaden or "piogey" fish, which are caught in large quantities off the Atlantic coast. There are several grades, the most satisfactory of which is the grade known as "light winter pressed." This oil is of pale straw color.
  Cottonseed oil.—This oil is pressed from the seed of the cotton plant. It is little used in paint manufacture.
  Corn oil.—This oil is a by-product in the manufacture of starch and alcoholic liquids. It dries slower than cottonseed oil and is used principally in color grinding.
  Soy-bean oil.—This oil is obtained by crushing, steaming, and pressing the seed of soy-bean plant. When mixed in proper propor-tions with linseed oil it gives fairly good service in some paints. It is a semidrying oil, but can be made to dry quickly by mixing it with lead manganese driers.

  Varnishes as such are discussed in more detail in chapter 8. Their principal applications as paint vehicles are in enamels, floor and deck paints, boot-topping paint, etc., where hardness, gloss, water resistance, and such properties are desired.

  The term "volatile thinner" has been defined as "All that liquid portion of a paint, water excepted, which is volatile in a current of steam at atmospheric pressure." The volatile thinners are liquids which form homogeneous solutions with the nonvolatile vehicle (oils or varnishes), and which, on exposure to the air, evaporate rapidly and more or less completely.
  Thinners are used in paints to thin or "cut" the oil or varnish to facilitate spreading, to reduce excessive proportions of oil or varnish, to hasten the "setting" of the paint, to assist penetration of the priming coat on wood, to reduce the gloss of undercoatings and improve the adhesion of subsequent coats, and to destroy gloss where flat finishes are desired.
  Thinners, however, should not be used in excess, as they will then seriously impair the durability of the paint by reducing the



proportion of nonvolatile vehicle (oil or varnish). As the nonvolatile vehicle in the paint is the "binder" or life of the paint, the thinning of the binder results in lessened durability.
  This result is very apparent in what is known as "flat" paint, where the proportion of oil is reduced by the addition of thinners to such an extent that the paint dries without gloss.
Turpentine.—Gum spirits of turpentine is obtained from pine trees by cutting pockets in the bark of the trees and collecting the sap drippings. When this sap is distilled it yields turpentine.
  Wood turpentine is produced by destructively distilling or steam distilling pine wood. High-grade refined wood turpentine has a sweet smell, is transparent, and equal to gum spirits as a solvent. It is accepted for use on a par with gum spirits of turpntine.
  Mineral spirits (turpentine substitute).—Turpentine substitute is a light volatile product collected in the distillation of crude oil. Where this product has the proper evaporating value, high flash point, and freedom from sulphur, it is very suitable as a paint thinner. It differs from the two turpentines in that it completely evaporates as the paint dries, and therefore serves only to dilute the oil. Turpentine, on the other hand, leaves on the surface of the paint a small percentage of glossy material, which, in a slight degree, acts as a "binder" for the pigments.
  Turpentine substitute is sometimes used as a thinner in varnishes. Varnishes made with turpentine substitute can not always be further reduced with substitute, because of the tendency of an excess to separate the gums in the varnish from the oil.
  If varnishes on board ship become too thick for proper application they should be thinned with turpentine.
  Benzol.—Benzol is a product obtained from the distillation of coal tar. A small portion of benzol is a valuable constituent of some paints.
  Toluol.—Toluol or toluene is a light oil distillate from coal tar. It has a higher boiling point than benzol. It is produced in commercial grades suitable for paint trade. It is not used by the Navy Department.
  Coal-tar naphtha.—Coal-tar naphtha is not used much in above-water paints, but is used in bottom paints and in varnishes. It is one of the products obtained in the distillation of coal tar.   Alcohol.—Alcohol is a product of the fermentation of sugar. The sugar solutions may be derived from grains, molasses, or fruit sirup, or by the treatment of wood with sulphurous acid. It is a colorless, very limpid liquid, having a pleasant odor and hot burning taste. It is very volatile when exposed to the air and evaporates completely. Although it is not much used in the trade, due to the high excise duty imposed on it, it is used extensively in the Navy as a solvent for shellac. The Navy Department purchases alcohol duty free, and for this reason it can be economically used.

  Driers are used to expedite the drying of a paint. It has been found that certain metallic compounds, when mixed with oil, add to its drying properties. When raw linseed oil is treated in this way and heated to a certain temperature for a definite length of time it becomes "boiled oil." It is for this reason that boiled oil dries more



quickly than raw oil. Liquid-paint drier, such as used in the Navy, is composed of compounds of lead, manganese, or cobalt, or mixtures of these, combined with an oil and reduced with volatile thinners.
  A drier acts on the oil in a paint and does not affect the pigment. The drier acts as a conveyer of oxygen which it takes from the air and gives up to the oil. The drier during this process temporarily changes its own composition, but immediately resumes its original condition as soon as it has given up the oxygen. This type of chemical action is known as catalysis.
  Linseed oil, when it absorbs oxygen, changes into a compound consisting of oil and oxygen known as linoxyn. This material, unlike the oil from which it has been formed, is a hard, elastic, nonsticky product, insoluble in most solvents. The same compound may be formed by applying some raw oil to a clean glass plate and exposing it to the air. The oil will absorb about 16 per cent of its own weight of oxygen from the air.
  Other oils, such as cottonseed, corn, and soy-bean oil, do not take up oxygen as readily as does linseed oil. The oxidizing properties of an oil determine whether it is classed as a "drying" or "semi-drying" oil.
  Driers are added merely to expedite the absorption of oxygen. The absorption process is too slow in oil without a drier to be of service in most paints, especially in quick-drying paints. However, as the final destruction of a paint is due to oxidation of the vehicle, anything which hastens oxidation shortens the life of the paint. Therefore, the addition of driers should be carefully limited. Too much drier may also cause "browning" or darkening of the paint.


















  A ready-mixed paint consists of a pigment, or more usually a combination of various pigments, nonvolatile vehicle composed of oil or varnish, or both, thinners, and driers. All of these ingredients have been described in the preceding pages.
  The ingredients of ready-mixed paints and the proportions of these ingredients are carefully selected to produce those coatings which will be most satisfactory under the conditions to which the paints will be exposed when used for the purposes for which they are intended. Only in rare instances is any advantage obtained by an attempt to alter ready-mixed paints, other than by the usual addition of small quantities of thinner for the priming coats on wood, etc.

  As a paint is essentially a mixture of solid and liquid ingredients, the pigments may, on long standing, separate from the vehicle and settle to the bottom of the container. A separation of this kind takes place in many paints where heavy pigments are used. Where the pigment sediment remains soft and can readily be stirred up, little or no harm results from such settling. Some paints, especially those containing chemically active pigments, such as red lead with a high litharge content, not only settle but harden so that the pigment becomes caked. Every effort is made to avoid such settling, as it is very difficult to remix a paint which has caked in this manner.

  The settling and caking is greatly reduced by incorporating in the paint an inert pigment of the type already described. These inert pigments get in between the particles of other pigments, prevent the uniting of the latter, and thereby reduce settling and almost entirely obviate caking.

  Experience has shown conclusively that a good paint will give unsatisfactory service if not thoroughly mixed before application. It is quite evident that when a paint has settled, the upper portion of the paint, near the surface, contains too much oil and too little pigment, A partial mixing of the paint, though it may appear to be uniform, if only casually examined, will not restore those proportions of pigment and vehicle which were put into the paint. It is essential that the mixing be thoroughly accomplished or the paint will not give the satisfactory service which it was designed to render.



  Experience and good judgment are required to know when a paint has been properly mixed.
  In general it is advisable to pour off most of the clear liquid at the top of the containers and thoroughly mix the material remaining in the container. Then add a little of the clear liquid, mix thoroughly and repeat the process, using a little liquid at a time until the whole has been added and the paint is uniform. There should be no streaks of color through the paint when stirred, nor any settled or "balled-up" pigment on the sides or bottom of the container.



























  Next in importance to a properly compounded, well-mixed paint is the careful cleaning of the surface. The old biblical adage, "A house founded on the sand will fall," holds true in paint work. The most expensive paint will be of little value as a protective or decorative coating if it is applied on an insecure foundation. The paint secures its hold on the surface by the penetration of part of the vehicles in the pores of the surface. If loose old paint, rust, dirt, dust, moisture, or grease exists on the surface, it will prevent the new paint from entering the surface pores.
  It should be borne in mind, therefore, that the first essential to good paint work is the proper preparation of the surface. Any in-fraction of this rule on the part of a painter will surely result in loss of his labor and his employer's material.
  When painting ironwork it is very important to remove all scales, grease, rust, and moisture. Rust has the property of spreading and extending from a center if there is the slightest chance to do so. Hence a small spot of rust on the metal may grow under the surface of the paint until in time the paint will flake off. For this reason it is very essential that all traces of rust shall be removed. Deep-seated rust spots may be removed by applying heat from a painter's torch. The heat converts the rust into another form, which is harmless and can be easily dusted off.
















  As all painting on board ship is done by brush, only this method of application will be considered. The following advice will be of value if properly followed.
  First, Hold the brush by the handle and not by the stock. If the brush is held by the stock the hands become covered with paint, which may cause blood poisoning, especially if small cuts are exposed and lead paints are used.
  Second. Hold the brush at right angles to the surface, with the ends of the brush alone touching, and lift it clear of the surface when starting the return stroke. If the brush is held obliquely to the surface and not lifted the painted surface will be uneven, showing laps and spots and a generally dauby appearance.
  Third. Do not completely fill the brush with paint. Dip only the ends of the brush into the paint. Do not charge the brush with paint until the preceding charge has become sufficiently exhausted.
  Fourth. Apply the paint with long strokes parallel to the grain of the wood. When painting along smooth surfaces draw the brush along the whole surface if convenient, so that there will be fewer "breaks in the lines.
  Fifth. Cross the work by laying off the paint over a small section with parallel strokes and then crossing the first application with parallel strokes at right angles to the first one. A medium pressure should be applied during the crossing and a light pressure during the final laying off. All final laying off should be in the length direction of the work.
  Sixth. When painting overhead surfaces, the ceiling panels should, as far as possible, be laid off fore and aft, and the beams athwartship. Where panels contain a great many pipes running parallel with the beams it would be difficult to lay off the ceiling panel fore and aft. In such cases better results will be obtained by laying off parallel with the beams.
  Seventh. When painting vertical surfaces, bulkheads, etc., the work should be laid off vertically. In all cases each succeeding coat of paint should be laid off in the same direction.
  Eighth. Keep the paint in the pot well mixed while the work is proceeding.
  Ninth. Remember that paint applied in a too heavy coat will show brush marks and will give an uneven finish. Better results will be obtained by applying two coats of thin or medium body paint than one coat of heavy paint.
  Tenth. Do not apply a succeeding coat of paint before a previous coat is sufficiently dry. A paint dries because of its contact with the air, and the drying of the first coat will be retarded if the second coat is applied too soon.











  After a container of paint has been opened and the paint partly used it should be covered and kept as air-tight as possible to prevent a paint scum from forming on the surface.
  When scums or foreign substances become mixed in with the paint it should, before being used, be strained through fine-gauge wire or cheesecloth.
  Do not expose shellac unnecessarily to the air, as the alcohol evaporates quickly from the shellac, thereby producing a thick, stringy mass.
  Do not allow nails or other iron substances to fall into shellac, as iron will discolor the shellac sufficiently to render it useless. Shellac should not be applied on a damp day, as moisture has a tendency to turn it white. Always pour unused paint back into the stock container and wipe out the empty pot with a brush. This will prevent skin forming on the sides of the pot and will keep the pot in good condition for the subsequent use.

























  For general work on board ship the following brushes have been found to be most suitable:

  Steps should be taken to tighten the bristles of all brushes before they are put in use, since paint and varnish brushes which are in every way satisfactory at the time of inspection when delivered by contractors may when issued from store be defective in that they shed bristles to a very objectionable extent. This shedding of bristles is due to the drying out of handles while in store. The bristles may be tightened by holding the brush in a vertical position with the bristles pointing up and wetting the end of the wooden handle inside the bristles with about a teaspoonful of water, then allowing about half an hour for the handle to swell, thus restoring the original pressure of handle and ferrule on the bristles; or it is still better to immerse the brush for 24 hours in water to top of ferrule.

  No matter how good a brush may be it will be ruined very quickly if not properly treated when not in use. A paintbrush after use should be thoroughly cleaned out in turpentine substitute or soap and water. If left in water for any length of time, the bristles are liable to twist and lose their elasticity. After cleaning, the brush should be kept in a trough containing a sufficient quantity of raw linseed oil to cover about one-half the bristles. Large brushes should have a small hole bored through the handle well up toward the stock. A wire can be inserted so that the brush can be suspended in the trough of oil. Brushes should never be stowed standing in buckets with the weight of the brush on the bristles. If large brushes




are allowed to stand on the point, they soon lose their shape and become useless.   (NOTE.—Should a paintbrush become quite hard with paint, it should be soaked for 24 hours in raw linseed oil and then in hot turpentine. This treatment will generally loosen up the bristles.)
  Varnish brushes should be suspended in the same kind of varnish with which they are used. If this method is not possible, boiled oil may be used instead. If a varnish brush has been thoroughly cleaned in turpentine substitute, gasoline, or soap and hot water it may be kept lying flat on its side in a suitable box.
  Lettering brushes should be washed in turpentine substitute or gasoline until clean. If they are not to be used for some time they should be dipped in olive oil and smoothed from heel to point.
  Shellac brushes should be kept in a small amount of mixed shellac or alcohol. Never put them in water. If the brush is not required for use in the near future, clean it in alcohol.

  To prevent the bristles in a round brush from spreading, it is good practice to bind the heel end of the bristles at the ferrule with cotton line. The effect of the serving or binding is to make the brush stiffer and to hold the bristles together. As the bristles becomes shorter, due to wear, the. binding can be removed. Flat brushes need not be bound.













  A varnish is a liquid coating material containing no pigment, which flows out to a smooth coat when applied and dries to a smooth, glossy, relatively hard, permanent solid when exposed in a thin film to the air. Some materials possessing the other characteristics dry without the usual gloss and are termed "flat varnish."
  Varnishes are used to enhance the beauty of surfaces and to protect the surfaces to which they are applied: also to increase the luster, hardness, and water resistance of other coatings, as when used for a vehicle in paints. The protective value of a varnish rests in its ability to exclude moisture, vapors, and other agencies of decomposition or corrosion.
  The varnishes used in the Navy may be classified under two types- oil varnishes, such as spar varnish and interior varnish, and spirit varnishes, such as shellac and damar varnish. The spirit varnishes are, substantially, solutions of gum resins, accomplished with or without heating in volatile liquid. Spirit varnishes dry by evaporation, usually quite rapidly. The oil varnishes are made by melting resins in kettles, mixing with heated drying oils, such as linseed or China wood oil, and cooking the melt at a temperature, and for a time, which will insure the desired consistency, waterproofness. etc., of the finished product. The varnish is then partially cooled and thinned with turpentine, mineral spirits, or a mixture thereof. Varnishes of this type dry partly by evaporation and partly by oxidation.
  After the surface to be varnished has been thoroughly cleaned, filled, and rubbed off, the varnish is applied with a brush in the form of a uniform coat by crossing the work and allowing the varnish to flow in a smooth coating. It is essential that the surfaces be thor-oughly cleaned from all dust particles, as these show plainly in the varnish.
  With oil varnishes it is essential that each coat be allowed to dry thoroughly (not less than three days) before another coat is applied. A second coat applied over a partially dried first coat will exclude air and retard the drying of the under coat. For the same reason varnish should not be applied in too thick a coating. The outer surface will dry first, forming a skin, and retard the drying of the varnish underneath. A hard surface coating produced in this way over a soft undercoating will result in early failure.
  The interior varnish used in the Navy may be employed to produce rubbed finishes. For a dull finish the varnish should be rubbed with pumice stone and water, then washed off and dried with damp chamois skin. For a gloss, rubbed finish, rub with pumice stone and crude oil, wipe and rub the surface with rotten stone, then clean with crude oil (8 parts), mineral spirits (1 part), finishing with cheesecloth or clean waste.






  Efficiency.—Experience extending over a number of years has indicated that the most efficient coating for metal work when applied on clean or new surfaces in double bottoms, inner bottoms, machinery spaces, and similar spaces is a material usually made from coal tar, pitch, or asphalt.
  Nature of material.—Bituminous composition is generally considered to consist of a bituminous solution, which is applied cold as a priming coat, and a bituminous enamel, which is applied hot over the solution. The solution consists of bituminous material thinned with a suitable solvent to a brushing consistency. The enamel consists of bituminous material of relatively high melting point, with or without the addition of mineral matter.


  (1) The solution will not adhere to a dirty surface, and as the solution forms a bond between the metal and the enamel, it is essen-tial that, prior to applying the solution, the metal surface be ab-solutely free from oil, grease, or rust. Many of the failures of bituminous compositions have been due to the applications of the material over dirty surfaces rather than to any inherent defect in the bituminous material itself.
  (2) Care must be exercised in heating the enamel previous to application. As this material has a tendency to boil over, the pot must be only partly filled. The mineral matter tends to settle out from the hot enamel, and hence the material must be kept well stirred.
  (3) The enamel should be applied to a uniform thickness of one-sixteenth to one-eighth inch. Care must be taken to see that the enamel completely covers the solution, as the solution itself affords but little protection. As the solution and enamel are both black, it may be difficult to see where the enamel has been applied, but with care and proper supervision this difficulty can be avoided.











  Kinds used.—Although in the past a number of proprietary bottom paints were used, the only bottom paints now used as standard are the anticorrosive and antifouling paints manufactured at navy yards. The formulas for these paints are given in "Instructions for Painting and Cementing Vessels, General Specifications, Appendix 6."
  Object of anticorrosive bottom paint.’As its name implies, an anticorrosive bottom paint is intended to prevent corrosion and con-sequent destruction of the underwater portion of the hull. The anti-corrosive paints are usually limpid, rather thin-bodied paints, these qualities allowing the paint to readily penetrate and coat all irregularities of the surfaces. Anticorrosive paints are not, as a rule, sufficiently strong to be used alone, nor will they protect the ship from fouling. The anticorrosive should always be covered with a coat of antifouling.
  Object of antifouling bottom paint.—The object of applying an antifouling bottom paint is to prevent the fouling of the ship's bottom and the consequent loss of speed and increased fuel consumption. The ingredients of antifouling paints which have been found most beneficial for preventing the attachment and development of marine growths are mercuric and cuprous oxides." The antifouling paint should not come in contact with the steel plating of the ship's bottom, as it is not designed to prevent corrosion and pitting may result if it is so applied.
  Preparation of surface.—It has been stated in the preceding section on the preparation of surfaces to be painted that all surfaces must be carefully cleaned. This statement is particularly true in the case of ship-bottom paints because of the service conditions to which these paints are subjected. Oil and grease frequently found near the water line must be cleaned off with gasoline or some other solvent of grease.
  Even though all loose paint has been scraped and chipped off, the anticorrosive paint will flake off almost as soon as it has been applied if the oil and grease have not been removed.
  Application of anticorrosive paint.—Before applying any paint stir each drum until the paint has reached a uniform consistency. The paint contains heavy pigments which settle rapidly and upon which the beneficial properties of the paint are dependent. It must be frequently stirred during its application. The anticorrosive paint dries very quickly because of the quick evaporating properties of its vehicle and should be applied with






short, rapid strokes while the operator progresses steadily over the area to be painted.
  Application of antifouling paint.—Bottom paints are designed to dry rapidly, and the antifouling paint can be applied very shortly after the anticorrosive paint. As in the case of the anticorrosive, the antifouling contains heavy metallic pigments. These impart to the paint its antifouling properties and must not be allowed to settle. Stir the paint frequently. Apply the antifouling paint only over the anticorrosive paint and not over bare metal.













  1.  Don't use shellac as a protective paint on steel surfaces or where it comes in contact with water or damp conditions.
  2.  Don't do any puttying until the first or priming coat has been applied and is dry.
  3.  Don't use boiled linseed oil for priming.
  4.  Don't forget that no paint made will prove successful when applied over a wet or damp surface, whether such surface is wood, metal, plaster, or cement.
  5.  Don't forget that painting or varnishing over a damp or tacky surface will cause blistering and alligatoring of paint and cracking of varnish.
  6.  Don't forget that red lead is a most excellent first coating for tin, galvanized metal, steel, or iron.
  7.  Don't apply varnish over a glossed surface. Haircloth or sandpaper will quickly remove the gloss and also improve the general appearance of subsequent coats.
  8.  Don't attempt to produce a successful job of rubbing with water or oil and pumice stone or of polishing with rottenstone before the varnish is thoroughly dry.
  9.  Don't forget that each coat of varnish must be thoroughly dry before applying another. If this fact is neglected, cracking will surely result.
  10.  Don't try to preserve steel surfaces unless examinations are frequent, surfaces are thoroughly cleaned, and repainting carefully done.
  11.  Don't forget that the volatile thinners used in paint are inflammable. Keep all flames away from open containers of paint.
  12.  Don't leave oily waste or rags in lockers. Rags saturated with paint oils are subject to spontaneous combustion.
  13.  Don't put waste or rags saturated with turpentine or mineral spirits in your pockets. These oils will soak through the clothes and blister the skin.








  Though cases of poisoning due to paints are very rare where ordi-nary precautions are taken to insure proper ventilation and personal cleanliness, a brief description of the poisonous effects of paints and of the means of preventing such effects is considered of importance in a manual of this character, because of the fact that some of the conditions under which poisoning can take place may be found on board ship.
  Poisonous effects may be produced by either the vehicle or the pigment of the paint. The vehicles, which may consist of linseed oil, turpentine, mineral spirits (turpentine substitute), and possibly naphtha, benzine, or benzol, are all, except linseed oil, volatile poisons. When used in the open they are not dangerous, because of the dissipation of the vapors by air currents; when used in confined places, without proper ventilating facilities, they are dangerous and may cause disorders, as follows:
  Turpentine.-Headache, dizziness, dry throat, frequent cough, indications of bronchitis, and irritation of the urinary system as shown by strangury and bloody urine. Turpentine is largely excreted by the kidneys, and there may be severe pains in the region of the kidneys; nervous effects are sometimes produced, such as excitement, staggering gait, convulsive movements, or even loss of consciousness. There may be inflammations of the skin of various kinds. A fatal case of poisoning from turpentine vapor is on record.
  Mineral spirits.—Very little data are on hand indicating that the vapors given off bv turpentine substitute are poisonous; in cases where it is claimed poisoning has resulted from the use of this material, the data furnished are insufficient to warrant the conclusion.
  Benzine or naphtha. —The vapors affect the nervous system, cause a sense of pressure in the head, a singing or roaring sensation in the ears, a sense of confusion, dizziness, and a loss of muscular strength. The manifestations are staggering, clouding of the memory, even hallucinations of sight and hearing. Labored respiration, rapid pulse, collapse with complete unconsciousness, and more rarely convulsions may result. There may also be skin inflammation.
Benzol. —The symptoms of acute benzol poisoning are headache, dizziness, a flushed face followed by cyanosis (blue jaundice), nervous excitement, hallucinations, delirium, or coma. In chronic cases there are inflammation and ulceration of the gums and lips, as in scurvy.
  Navy paints. —It should be remembered in connection with the above that the Navy Department does not use benzol or benzine in its paints, and for this reason there should be little or no poisoning from the fumes given off by such paints.





  Prevention of poisoning by vapors. —The deleterious effects of these vapors are minimized by proper ventilation of confined spaces and, in extreme cases, by the proper use of gas masks. Some of the vapors, such as benzol, given off by paints and lacquers are heavier than air and are not carried off by overhead ventilation unless forced. Steps should be taken to insure adequate ventilation in all cases where paints or lacquers are to be applied in confined spaces, especially when applied by spray apparatus.
  Dry sandpapering. —Dry sandpapering of painted surfaces con-taining lead pigments is considered dangerous. It produces a fine powder of lead, which floats through the air. It may be inhaled, caught in the mouth and throat, mixed with saliva, and swallowed. It is estimated that less than a quarter of the dust taken into the human system reaches the lungs. Some lead poisoning is due to absorption of the fine dust through the pores of the skin.
  PREVENTION : Use pumice stone and water or oil, or moisten the sandpaper with a cheap mineral oil which does not dry too slowly or too rapidly. The sandpaper will last as well with as without oil, and the effect upon the paint is negligible.
  Rubbing or chipping old paint. —In confined spaces a possible source of danger is flakes or chips of paint falling to the floor or drop cloth and becoming powdered from being stepped upon.
  PREVENTION : Do not let the flakes or chips of paint collect; dampen the paint and install as thorough a system of ventilation as possible.   Burning off old paint. —This process is dangerous if the burnt-off paint is allowed to remain on the floor and be powdered by being stepped upon. The flame of the torch should not be allowed to play long enough on the surface of the paint to produce a smoke. The heated oil fumes may cause headache. Fine particles of lead may be carried mechanically along with the fumes and thus be inhaled. Masks should be worn to prevent the fumes being inhaled.
  Danger from dusty clothing, etc. —The danger from dusty clothing or drop cloths is the same as that resulting from inhaling paint dust, as explained above.
  PREVENTION : Clothing should so far as possible be kept in a clean place away from the dust-laden atmosphere.
  Danger from unwashed hands. Every painter runs the risk of carrying lead into his mouth if he handles his food, tobacco, etc., with unwashed hands. The risk is greater with greasy foods such as buttered bread and meat, as paint comes off easily on an oily surface.
  PREVENTION : Personal cleanliness. Oil paints should be removed from the hands with warm water, soap, and brush, or with linseed oil, if necessary. Dry with clean towels. Painters should not use turpentine to clean paints off their hands. This will lead to what is known in the trade as "drop wrist." Do not eat in a paint-dust atmosphere.
 Before handling putty the painter should coat his hands with soapsuds or raw linseed oil. This will prevent the putty from sticking to his hands and will permit easy cleaning.   Poisoning due to pigments. —The poisonous pigments are white lead (basic carbonate of lead), sublimed white lead (basic lead sulphate), and red lead. Of these three pigments, the white and




red lead are the most poisonous, the basic sulphate white lead being considerably less dangerous than either of the other two leads. The toxic effects of these pigments is known as lead poisoning.
  Cause of lead poisoning. —Lead poisoning is not caused by the vapors given off by a freshly painted surface, but may result from the following:
  1. Mixing dry lead with oil or paint.
  2. Dry sandpapering of lead-painted surfaces.
  3. Rubbing or chipping off old paint.
  4. Burning off old paint.
  5. Inhaling dust from dirty working clothes and from dirty drop cloths.
  6. Inhaling fine particles of lead paint from a paint-spraying machine.
  7. Carrying lead paint into the mouth from unwashed hands.
  Mixing dry lead. This source of poisoning is neglible, because white lead dry is very seldom handled by the painter. Red lead is also now being furnished ready mixed.













National Archives & Records Administration, College Park
Record Group 19, General Specifications for Ships & Machinery

Transcribed by RESEARCHER @ LARGE. Formatting & Comments Copyright R@L.

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