TM 1-1500-204-23-1 b. Maintenance   of   Protective   Covers.      Cleaning, repair, waterproofing, and storage of protective covers are explained in the following paragraphs. (1) Cleaning.    Protective  covers  contaminated with  salts  from  the  atmosphere,  specifically  chlorides  (in marine    areas)    and    sulphur    compounds    (in    industrial areas),  can  promote  corrosion  of  aircraft  skins.    Grease, oil,  or  dirt  can  mar  or  discolor  plexiglas  portions  of  the aircraft Therefore, only clean covers will be used.  Clean protective covers using the following procedures. NOTE To   increase   life   expectancy,   protect covers against rain, wind, snow, sand, and   mildew   when   not   Installed   on aircraft. (a) Remove all possible ropes and wooden attaching parts. (b) Tape or wrap all attaching parts, such as  buckles,  snaps,  hooks,  and  D-rings  to  prevent  tearing and snagging of covers during soaking or washing. (c) Brush  soiled  section  with  firm  bristle brush to remove excessive soil. (d) Select    a    container    that    will    hold enough liquid to allow complete immersion of cover to be washed. (e) Mix soap solution containing 3 ounces of low strength laundry soap, Federal Specification P-S-1792, to each gallon of water. Synthetic detergents are permissible when available. NOTE The  temperature  of  water  should  not exceed 100°F (37°C) (f) Immerse one cover at a time in soap solution for a period not to exceed 30 minutes. (g) Rinse   over   In   clean   water   until   all soap has disappeared. (h) Spread  covers  on  a  clean  surface  to dry. (2) Repair.   Make   prompt   repairs   to   aircraft protective   covers   to   prolong   service   life.      Inspect   for damage  immediately  after  use  and  make  repairs  using the following paragraphs. (a) Puncture,    snagged,    or    torn    areas. Repair punctured, snagged or torn areas as follows: 1  Repair punctured, snagged, or torn areas by sewing in place a patch of material equal to basic material in weight, quality, and color. 2    Reinforce  and  darn  punctures and small holes (1/2 Inch or less). 3   Trim   and   turn   under   frayed edges to make a neat and durable repair. 4  Use  circular  patches  on  small holes  and  rectangular  patches  on  larger  holes,  irregular snags, or tears. 5   Mend   a   cluster   of   holes   with one suitable patch, after first removing damaged area and turning under all edges. 6    Provide    best    possible    water drainage    by    extending    patch    seams    diagonally    from centerline of cover section whenever possible. 7   Do   not   extend   patches   over more than one section of cover (seam to seam). 8 Restitch all open seams.  Stitch pattern and type thread will follow as near as possible the type stitch and thread used in original construction of item being repaired. (b) Edge damage.  Repair edge damage as follows. 1   Repair   damaged   areas   along edge  of  covers  where  grommets  or  attaching  points  are located  by  folding  a  piece  of  material  equal  to  the  basic material over damaged area by sewing In place. 2   Replace   corner   areas   where attaching    points    are    located    by    sewing    on    a    patch composed of three thicknesses of material equal to basic material. 3   Replace   any   worn   or   missing webbing keepers, defective elastic webbing, or reinforcement patches. 9-47