Facilities

TM 750-245-4

procedures are being properly performed. The inspector

residues which accelerate corrosion or interface with

should halt all painting operations found defective and

adhesion or continuity of the preservatives are present

insure that corrective action is taken. The inspector will

on the surface of the part prior to application of the paint

generally inspect:

or finish. Improper cleaning makes all subsequent

painting and finishing operations ineffective.

(1) Equipment after proper cleaning is

accomplished for evidence of scale, dirt, paint peel,

blisters, etc.

c. Metal items which are to be given chemical

protective finishes or coatings must be cleaned so that

(2) Proper painting in accordance with the

their surfaces are completely free of dust, grit, grease,

applicable requirements of the particular item. Refer to

oil, acid, alkaline, and salt residues, corrosion, and other

existing system documentation for these requirements.

contaminants. The presence of contaminants may

(3) To insure that moving parts and machined

cause the fissures, or other surface defects that are

surfaces, unless otherwise specified, are protected from

points of entry for corrosive substances and thus make

paint.

the coating ineffective. The cleaning method chosen

(4) To insure that exposed bearings, glass,

must be most suitable for the material of which the part

rubber gaskets, canvas, and gears will not be exposed

is made and the service requirements of the finished

to paint.

item.

(5) Condition of surface prior to painting to

2-8. Facilities

insure that all moisture, soil, and contamination has

a. Painting. Painting shall be done in a clean, dry,

been removed.

well-ventilated space.

It is preferred that the air

b. Finishing. The inspector should perform an in-

temperature be between 60 to 90 degrees and the

process inspection, periodically, to insure that finishing

relative humidity not over 65 percent. Painting should

requirements are being met. He should also perform an

not be done when the temperature is below 50 degrees

in-process inspection anytime items are not meeting the

Fahrenheit or when the humidity is above 85 percent.

final finish requirements.

All defects should be

Materials shall be thoroughly mixed and there shall be

corrected before permitting additional finishing of items.

no settling or separation of ingredients during painting

The inspector's in process inspection should generally

operations. Unless otherwise specified, coatings may

insure that:

be applied by any method that will insure the application

(1) Contaminants which absorb moisture or

of a smooth, uniform, continuous film, free from direct

accelerate corrosion, are removed as soon as possible.

overspray, runs, sags, blisters, orange peel, or other

Oil, grease, and adherent nonporous oxide coatings

imperfection. Unless otherwise specified, baking of

may afford some protection against corrosion, but in

coats of paint shall be done at a temperature of 250

most cases, must be removed before corrosion-

degrees Fahrenheit for 45 minutes. Freshly painted

preventive compounds, chemical protective finishes,

material shall not be exposed to conditions that will

electroplated metal, or paint finishes are applied.

harm the paint. Pretreatment coating (primer wash,

(2) Materials used for finishing, which have

pretreatment blue, formula 117-B for metals) shall be

not been accepted previously, are inspected and sample

applied by spraying, brushing, roller coating or

tested to determine compliance with the requirements

swabbing. However, in the case of magnesium, this

as specified in the system documentation.

coating shall not be applied unless the magnesium has

an adequate protective film and conforms to the

(3) Items to be painted after finishing are

appropriate system documentation.

clean and that the finish meets the required standard.

b. Finishing.

The finish facilities are usually

(4) The inspector may, at his discretion, have

test specimens made from the same type metal, coated

separate from other work areas. The requirements are

identically, and processed concurrent with the processed

generally the same as for the painting area above, with

items. These specimens should be checked for proper

the exception of temperature. Application of finish coats

thickness (generally 4 to 5 mils), and final finish to

does not require temperature control as does painting.

insure proper processing.

2-9. In-Process Inspection

a. Painting. The inspector should perform an in-

2-10. Final Inspection

process inspection periodically. He should also perform

a. Painting.

The inspector should inspect all

an in-process inspection anytime painted items are not

painted items. These inspections will insure that the

meeting the final painting inspection requirements. In-

item meets required standards and is ready for use.

process inspections are made to determine that all

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