Repainting

TM 38-260

(a) Air filters. Spun glass air filters shall be removed, discarded, and replaced by new spun glass filters.

Metal air filters shall be removed and cleaned by immersion and agitation in soapy water or in petroleum solvent,

conforming to P-D-680, type II. Cleaning in soapy water shall be followed by a rinse of clean water. Immersion in

solvent shall be followed by a final immersion in clean petroleum solvent. After being dried, the metal filters shall be

replaced without being reoiled. Attach a tag to each metal filter with the following instruction: "Reoil Filter Upon

Reactivation of Equipment. "

(b) Vacuum tubes. Vacuum tubes (except water-cooled) should not be removed from their sockets for

cleaning unless the condition of the rest of the equipment indicates that contamination probably exists between the tubes

and sockets. Contamination on tube pins may be removed with petroleum solvent and clean, lint free cloth, but shall not

be removed with crocus cloth or sandpaper.

drying procedures listed in paragraph 2-3.

(9) Repainting. Surfaces from which paint is removed may be smoothed with fine sandpaper or crocus cloth,

cleaned, and repainted in a matching color. The exterior surfaces of doors, panels, and cabinets are the ones most likely

to require repainting.

(10) Preservation. A common method for preserving and packaging electronic equipment utilizes water-

vaporproof barrier materials in conjunction with absorbent agents such as a desiccant. In controlled humidity enclosures,

this preservation procedure need not be used. There are, however, other requirements that are necessary to adequately

protect electronic equipment. These include application of moisture-fungus proofing compounds, silicone compounds to

connectors, insect and rodent control, and specific physical protection procedures.

(11) Corrosion of electronics is influenced by three major factors, namely; humidity, temperature, and

environmental contamination. Relative humidity above 50 percent drastically increases the rate of corrosion, however, it

is not the sole factor causing corrosion. The environmental contamination by pollutants such as reactive sulfides and

chlorides is a significant factor in the corrosion process. Corrosion can occur at extremely low levels of contamination

and low levels of relative humidity. Temperature is also significant since expansion and contraction of metals causes

movement of components which in turn causes certain types of corrosion. Humidity controlled warehouses or hutments

as discussed in chapter 5, along with temperature regulation, is recommended whenever possible to control the elements

of corrosion.

(12) Rodent and insect control. Positive control of rodents and insects is required where electronic gear is

stored in the clear, not individually boxed or crated. The destructive effects of rodents and insects can be significant

wherever electronic equipment is stored. The application of any or a combination of fumigants, poisons, traps, and

physical protection required for effective control must be employed to prevent damage to electronic equipment.

Historically, rodents have caused severe damage to wiring and electronic components in laid away equipment by nesting

among the circuitry and gnawing on the plastic coated wires. Investment in controlling this problem is a requirement.

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