TASK 70-60-00-620-001
1 . General.
Engine parts made of noncorrosion-resistant materials should be protected if they are permitted to stand for more than a few minutes. Examples of noncorrosion-resistant materials include chromoloy, alloys of aluminum, magnesium and copper, and corrosion-resistant alloys that have been nitrided or malcolmized. Parts containing dissimilar metals are also subject to corrosion. This practice does not apply to assembled engines, bearings, electrical parts or accessories.
2 . Protection of Parts in Process.
Subtask 70-60-00-620-011
A.Noncorrosion-resistant materials should be preserved during the overhaul process of inspection and repair by one of the following procedures. If a preserved part is handled before expiration of the preservation period, or if the preservation period expires, the part must be reprocessed at once.
NOTE:
Bearings require special handling. Refer to TASK 70-60-01-620-002, Preservation of Antifriction Bearings.
B.For preservation up to five days, use the following process.
(1)Clean parts to be sure that they are free from oil, grease, dust, or shop soil.
(2)Dip or coat the parts with one of the methods that follow using a solution or a preservation oil and air-dry.
(a)Use a solution of one part inhibitor C02-056   to ten parts water or use solution S1156.
(b)Use preservation oil C02-064  .
(3)Cover to protect from dust.
C.For preservation up to ten days, use the following procedure.
(1)Clean parts to be sure that they are free from oil, grease, dust, or shop soil.
(2)Dip or coat the parts with preservative oil C02-054  .
NOTE:
Effective preservation time can be doubled if parts are wrapped (not merely covered) in 4-mil polyethylene sheet.
(3)Cover to prevent dust contamination.
D.For preservation up to 20 days, use the following procedure.
(1)Clean parts to be sure that they are free from oil, grease, dust, or shop soil.
(2)Dip or coat the parts with preservative oil C02-050  .
NOTE:
Effective preservation time can be doubled if parts are wrapped (not merely covered) in 4-mil polyethylene sheet.
(3)Cover to prevent dust contamination.
E.For preservation up to 30 days, use the following procedure.
(1)Clean parts to be sure that they are free from oil, grease, water, dust, or shop soil. Blow dry with clean shop air.
(2)Submerge parts in storage preservative C02-055   or equivalent. If parts are moist, or contain water in crevices or blind areas, leave them in the preservative for at least 30 minutes.
NOTE:
Effective preservation time can be doubled if parts are wrapped (not merely covered) in 4-mil polyethylene sheet.
(3)Drain off excess preservative, and cover to prevent dust contamination.
3 . Protection of Parts for Storage.
Subtask 70-60-00-620-012
A.The following instructions apply to the protection of parts that are to be stored for extended periods.
(1)Painted Surfaces.
In general, painted surfaces do not require protection beyond a simple dust cover. If the paint is chipped or missing in spots, it should be touched-up before the part is stored.
(2)Plated Surfaces.
In general, plated surfaces require no protection other than a dust cover. Silver-plated parts must be wrapped in anti-tarnish paper and stored in sulfide-free containers.
(3)Uncoated Surfaces.
Metallic surfaces that are not normally coated or plated are most susceptible to corrosion. Iron and steel alloys are usually considered the most vulnerable. Stainless steels such as 321 and A286 do not require protection; however, the 400-series of stainless steels does require it. Brass and bronze should be protected. Process parts as follows.
(a)Apply a coat of preservative C02-054   to the part by dipping, brushing, or spraying.
(b)Place the part in a plastic bag or other vapor-proof container to protect it from dust, dirt, and moisture, or wrap in paper if size requires it.
(4)Parts with Cavities.
Parts that have cavities subject to corrosion or rusting should be filled with engine oil C02-019  , then drained thoroughly, to protect the internal surfaces. Plug or cover all openings and ports to prepare for storage.
4 . Protection of Fuel and Lube Components.
Subtask 70-60-00-620-013
A.Fuel and lube components must be handled individually, as follows.
(1)Lube Components.
Preserve with engine oil C02-019  , and seal if possible. Partially assembled components may be wrapped in 4-mil polyethylene wrap.
(2)Fuel Components.
Totally displace fuel with jet engine lubricating oil C02-021  . Seal all ports and openings. Partially assembled components may be handled as in Subtask 70-60-00-620-012, Protection of Parts for Storage.