TM 1-1500-204-23-3 (j) Fitting   Damage/Finish.      Fittings   which   have inter-crystalline   corrosion   or   scratches,   outside   of   the critical  sealing  surface,  to  a  depth  of  .030  inch  can  be reworked. (k) Repair/Replacement   of   Internal   and   External Support Fittings.  Loose or separated support fittings can be cleaned, buffed, cleaned again and cemented back in place. (3) Damage  that  is  not  reparable  is  classified as follows: (a)    Damage which extends into a comer. step off area.  or involves a cut longer than 4 inches is not reparable. (b)    Damage  which  has  led  to  activation of the sealant ply/plies is not reparable. (c)    Damage   to   cells   which   cannot   be repaired    by    cement    or    reinforced    patching    is    not reparable. (d)    Hole  damage    which  penetrates  the entire cell wall is not-reparable. c. Repair  Fuel  Cell  Outer  Coating,  Interior/Exterior Loose Fitting Flange and Interior Loose Seam Damage. WARNING Acetone,  barrier  cement,  repair  adhesives and   its   components   are   flammable   and toxic.      They   can   irritate   skin   and   cause bums.  Use only with adequate ventilation and  wear  a  NIOSH  approved  air-purifying respirator  for  organic  vapors.    Keep  away from   heat   or   open   flame.      Wear   safety glasses, gloves and protective clothing to avoid contact with skin, eyes and clothes. If  contact  occurs,  flush  areas  with  water and get medical attention for eyes. Repair   blisters,   cuts,   tears,   snags   and   abrasions   that damage   but   do   not   penetrate   the   outer   reinforcement plies (no fabric damage) as follows: (1) Use knife and trim away loose, damaged or blistered   outer   coating   (figure   2-24),   except   for   loose fitting flange repair. Figure 2-24.   Removing Outer Coating (2) Clean   damaged   area   using   a   dean   cloth (item   16,   table   2-11)   dampened   with   acetone   (item   3, table 2-11).  Wear gloves (item 4, table 2-11). WARNING Ensure all drills are non-sparking. (3)    Buff    surface    around    damage    314    inch larger in all directions than damaged area (1, figure 2-25). Use portable drill (2), abrasive arbor, and/or scotch-brite. Buff  only  to  remove  gloss  without  excessively  reducing outer coating thickness. Figure 2-25.   Buffing Damaged Area Change 2       2-45