paint requirements for preservation of a destroyer every 60 to 70 days are 270 gallons. All of this is a way of saying the Navy uses a lot of paint. The more attention you pay to the basic instructions, the less paint you will have to use. The Navy uses paint primarily to preserve surfaces. It seals the pores of steel and other materials, prevents decay, and arrests (stops) rust and corrosion. Paint also serves several other purposes. It is valuable as an aid to cleanliness  and  sanitation  because  of  its  antiseptic properties and because it provides a smooth, washable surface. Paint is also used to reflect, absorb, or redis- tribute  light.  For  example,  light-colored  paint  on  a ship’s interior distributes natural and artificial light to its best advantage. Learning to paint properly requires the selection of suitable paints for the surfaces to be covered, the proper preparation of the surfaces before painting, and the correct methods of applying paint. Though the selection of suitable paints won’t concern you now, you should know how to prepare the surface and how to apply paint with a brush and roller. Improper surface preparation and paint application, in that order, are the greatest reasons for paint failure. PREPARING THE SURFACE For paint to stick to a surface, all salt, dirt, oil, grease,  rust,  and  loose  paint  must  be  removed completely, and the surface must be thoroughly dry. Salt and most dirt can be removed with soap or detergent and freshwater.  Firmly  imbedded  dirt  may  require scrubbing  with  scouring  powder.  When  scrubbing won’t remove oil and grease, they may be removed with paint  thinner  or  other  approved  solvents.  After scrubbing or scouring, always rinse the surface with freshwater. Equipment and Procedures The removal of rust, scale, and loose paint requires the use of hand tools or power tools, paint and varnish removers. Hand tools are usually used to clean small areas. Power tools are used to clean larger areas and for completely cleaning decks, bulkheads, and overheads covered with too many coats of paint. Paint and varnish removers are used to remove paint from wood. HAND TOOLS.—The most commonly used hand tools are sandpaper, wire brushes, and hand scrapers. Sandpaper.—Use sandpaper to clean corners and to feather paint. (NOTE: To feather paint, you taper the edges of chipped areas down to the cleaned surface so that no rough edges remain.) Paint will bond best to a clean surface that has been lightly sanded. Sandpaper  is  graded  from  12  to  600,  which corresponds to the size of the abrasive grit on its surface. For example, the coarsest sandpaper is 12 grit and the finest is 600 grit. Very fine emery (a natural abrasive) paper  is  sometimes  used  to  polish  unpainted  steel surfaces.  However,    never    use  abrasives,  such  as sandpaper,  on  unpainted  galvanized  metal  (brass, copper, nickel, or aluminum) surfaces. Hand Wire Brush.—A hand wire brush is a handy tool for light work on rust or on light coats of paint. You can also use hand wire brushes for brushing weld spots and cleaning pitted surfaces. Hand Scraper.—Hand scrapers are made of tool steel. The most common type is L-shaped, with each end tapered to a cutting edge like a wood chisel. Hand scrapers are useful for removing rust and paint from small areas and from plating less than 1/4 of an inch thick when it’s impractical or impossible to use power tools. Chipping (Scaling) Hammer.—Occasionally, it’s necessary  to  use  a  chipping  or  scaling  hammer. However, take care to use only enough force to remove the paint. Too much force dents the metal, resulting in high and low areas. In painting, the paint naturally is thinner on the high areas. Therefore, if you leave high and low spots, rust will form on the high spots and, in time, spread under the good paint. PORTABLE  POWER  TOOLS.—The  most useful power tool is the portable grinder (fig. 18-1). Portable grinders are usually equipped with a grinding wheel that may be replaced by either the rotary wheel wire brush or the rotary cup wire brush. Light-duty brushes are made of crimped wire. Use them to remove light rust. Heavy-duty brushes are made by the twisting of several wires into tufts. Use them to remove deeply imbedded rust. 18-11 Student Notes: