TM 1-1500-204-23-9 e. Pattern   Troubleshooting.      Figure   5-10   shows common faults associated with spray patterns. 5-4. Oil  Spray  Guns.    Oil  spray  guns  operate  on  the same principles as paint guns as discussed in paragraph 5-3. a. Use      This  type  of  spray  gun  employs  nozzle fittings long enough to reach out-of-the-way places, and is  used  to  clean  aircraft  engines  and  parts  or  to  apply pickling  solution  to  an  engine  that  is  to  be  placed  in storage.  Atypical oil spray gun is shown in figure 5-11. WARNING Drycleaning    solvent    is    flammable    and solvent  vapors  are  toxic.    Use  P-D-680, Type  II  Solvent  in  a  well-ventilated  area. Keep   away   from   open   flames.      Avoid prolonged solvent contact with skin. b. Care.  To clean oil spray guns, use drycleaning solvent,  Federal  Specification  P-D-680,  and  follow  the procedures outlined in paragraph 5-3d. 5-5. Cleaning   Guns.      Cleaning   guns   are   used   for applying  air  or  solvent  under  pressure  to  parts  which must be cleaned. a. Types.  There are two main types of cleaning guns: the solvent cleaning gun and the air blow clean- ing gun. (1) Solvent     cleaning     gun.          The     solvent cleaning gun, shown in figure 5-12, is used for applying a spray of solvent to engines and other structures which are cleaned with solvent. (2) Air   blow   cleaning   gun.      The   air   blow cleaning gun, shown in figure 5-13, is used for applying a  direct  blast  of  air  to  clear  away  dirt,  dust,  and  metal shavings, or to air dry parts cleaned with solvent. b. Use.      The   following   paragraphs   describe   the procedures for using these cleaning guns. (1) Solvent     cleaning     gun.          The     solvent cleaning gun is operated as follows: (a) Connect  an  air  hose  to  the  air  inlet connection. (b) Insert the pickup tube into a container of the appropriate solvent. (c) Squeeze   the   trigger   to   expel   the solvent from the nozzle. (2) Air   blow   cleaning   gun.      The   air   blow cleaning gun is operated as follows: (a) Connect  an  air  hose  to  the  air  inlet connection. (b) Point the nozzle at the work. (c) Press the lever to expel the air. c. Care.    Observe  the  following  practices  for  the care and upkeep of cleaning guns: (1) On solvent cleaning guns, ensure that the hose  and  pickup  tube  are  not  clogged  or  restricted  in any way. (2) Keep  the  nozzle  clear  so  that  the  flow  of solvent or air is not impeded. 5-6. Pneumatic   Vacuum   Cleaner.      The   pneumatic vacuum cleaner, shown in figure 5-14, is used to clean up  metal  shavings  which  result  from  drilling  and  filing jobs on aircraft and in shops.  The attachments give the vacuum cleaner versatility.  These attachments include a  round  brush,  a  crevice  tool,  a  fan-shaped  end,  and tube extensions of varying lengths.  The bag should be emptied regularly and replaced as necessary. 5-7. Pneumatic Drill.  Pneumatic drills are used where sparks from an electric drill might become a fire hazard. a. Types.    Pneumatic  drills  that  are  available  are straight,   set   at   90   degrees,   or   rotate   through   360 degrees, as shown in figure 5-15.  These different types allow a part to be drilled in just about any location. b. Use.      The   following   paragraphs   describe   the procedures for using pneumatic drills: 5-5