Preservative Application

TM 38-260

NOTE

COMPOUNDS MIXED WITH SOLVENTS SUCH AS THOSE

SPECIFIED AS P-2, P-3, P19, AND P-21 OF TABLE 2-1,

MUST BE THOROUGHLY MIXED PRIOR TO USE.

2-6.

Preservative Application

a. General. Most P-type preservatives are oily or greasy in nature, and vary greatly in chemical composition

and consistency. For this reason they cannot be indiscriminately used on all kinds of materials. They may destroy the

usefulness of an item due to the difficulty of their removal. A preservative may penetrate into unwanted areas and cause

swelling or decomposition of some of the materials.

b. Application requirements. Petroleum or P-type preservatives, are applied to those metal surfaces on which

corrosion in any form, such as oxides, sulfides, and verdigris could occur. The type of preservative to be used on a

particular item is usually specified in procurement documents or processing specifications. In the absence of specific

instructions, the choice of preservatives is made from those listed in table 2-1. Care must be taken that the preservative

selected will not damage the mechanism, structure, or function of the item either when applied, in use, or during removal.

c. Exceptions to the application requirements. P-type preservatives are not applied to surfaces which are

protected with solid film lubricants such vitreous plastic, primer, or paint. They are not normally used on noncritical metal

surfaces that are inherently resistant to corrosion, such as items made from copper, nickel, chromium, brass, bronze, or

other corrosion resistant metals and alloys. P-type preservatives are not applied to noncritical items that have been

coated with materials such as chromium, silver, nickel, cadmium, zinc, or tin. Oily type preservatives are not applied to

items that are vulnerable to damage by the petroleum ingredients such as those fabricated from textiles, cordage,

plastics, mica, rubber, paper, felt, leather, and leather products, or pre-lubricated bushings. These preservatives are not

applied to certain types of electrical and electronic components or equipment such as condensers, electrical connectors,

distributor rotors, circuit breakers, fuses, switches, resistors, and rectifiers. P-type preservatives are not applied to any

item which would suffer damage to the mechanism or structure, or where malfunction or unsafe operational conditions

would result from the application or removal of the preservative.

d. Application of preservatives. After the proper preservative is selected, it must be applied to the item(s),

assuring that a uniform continuous coating of the preservative adheres to the item(s). Preservatives shall be applied to

previously cleaned interior and exterior unpainted surfaces by one or more of the methods of application listed in (1)

through (8) below.

(1) Dipping. Dipping is applicable to the preserving of parts that can be dipped in the preservative

material at room temperature. Dipping is well suited to applying preservative oils and solvent cut back preservative

compounds.

2-18