WARNING

When using any paint product, particularly lead-base paint, all current health and safety regulations will be strictly enforced. Contact the activity health/ safety department/ office to obtain all applicable regulations and instructions pertaining to a safe painting environment.

All Navy equipment shall be treated and painted in accordance with MIL-STD-1223. Equipment painting shall meet all specifications and standards referenced within MIL-STD-1223. Colors and color numbers that are authorized for use when painting CESE are as follows:

Before painting, a coat of primer should be applied to prevent peeling and flaking where bare metal is exposed. The primer serves as a bond between the paint and the metal of the vehicle. Each coat of primer that is applied should be allowed to dry and must be sanded lightly between coats. There may be occasions to use two coats of primer, but normally one coat is adequate.

Paint and primer must be shaken or stirred thoroughly, thinned with a thinning agent, and ran through a strainer or filter when using a spray gun. One of the "musts" of spray painting is that the paint should have the correct viscosity. This can be determined by following the instruction of the paint can. Too many painters determine the viscosity by the rate at which the paint runs from the stirring stick. This can lead to plenty of trouble, since only a slight change in viscosity can spoil an otherwise good job. This happens because the amount of thinner not only determines the thickness of the coat but also influences the evaporation rate between the time the material leaves the spray gun and the time it contacts the body panel.

NOTE
High viscosity paint produces paint sag and orange peel, while low viscosity paint produces improper flow out and waste of thinner. To avoid these problems, take care to measure the proportions of thinner and paint accurately in a graduated measuring cup.

The temperature at which the spraying is done is also an important factor in turning out a good job. This applies not only to the temperature of the shop but also to the temperature of the vehicle. Shop temperatures should be maintained at approximately 70 F. Whenever possible, bring the vehicle into the shop well in advance of painting so that it becomes the same temperature as the shop. Spraying paint on a surface that is too cold or too hot from being in the sun will upset the flowing time of the material and will cause orange peel and poor adherence to the surface.

Another important factor in doing a good job is the thickness of the paint film on the surface. Obviously, a thick film takes longer to dry than a thin one. As a result, the paint will sag, ripple, or orange peel. Ideally, you should produce a coat that will remain wet long enough for proper flow out. but no longer. The amount of material you spray on a surface with one stroke of a gun will depend on the width of the fan. the distance of the gun from the sprayed surface, the air pressure, and the amount of thinner used.

In addition, the speed of the spray stroke will also affect the thickness of the coat. The best procedure is to adjust the gun to obtain a wet film, which will remain wet only long enough for good flow out. Get the final thickness by spraying an additional coat after the first one has dried.

Nearly all-standard spray guns are designed to provide optima coverage when held at a distance of 8 to 12 inches from the surface to be painted. When the gun is held too close, the air pressure tends to ripple the wet film, especially if the film is too thick. If the distance is too great, a large percentage of the thinner will be evaporated in the spraying operation. Orange peel or a dry film will result. because the spray droplets will not have opportunity to flow together.

It is imperative, then. to hold the spray gun at the specified distance from the work. In addition, do NOT tilt or hold the spray gun at an angle. Also, never swing the spray gun in an arc. but move it parallel to the work. The only time it is permissible to fan the gun is when you want the paint to thin out over the edges of a small spot. Figure 8-68 shows the method for using a spray gun.

Another ingredient that is sometimes added to the paint is "drier." This substance causes the paint to set and dry much more rapidly than normal. Because a small amount of drier is all that is required, the instruction on its use must be followed closely. Mixing paint and adding drier are two critical parts of painting vehicles. Use of the wrong type of thinner, paint, or excessive drier will cause the paint to fade. peel, or blister within a short period of time after completing the job.

Painting instructions for using chemical agent resistant coating (CARC) and the camouflage painting of CESE equipment are found in the NAVFAC P-300.