20-60 Priming and Painting (continued)
A. Priming (continued)
Use only approved materials listed in Section 20-70. Parts shall be prepared in the following
manner:
1. Preparing Aluminum
Unless otherwise specified, chemical conversion coating using Alodine 1201 is the
standard treatment before priming aluminum. Follow manufacturers instructions for
application of Alodine. However, if bare or clad aluminum is primed without conversion
coating, the following procedure must be used:
a. Alkaline clean if immersion is practical, otherwise wipe clean with QSOL 220 or
equivalent degreasing agent.
b. Lightly scuff the surface with Scotch Brite pads.
c. Wipe with a tack rag to remove any foreign material or damp wipe with QSOL 220
or equivalent solvent.
d. Air dry. Do not touch parts with bare hands until primed.
2. Preparing Steel
Alkaline clean is the preferred method for cleaning steel except where immersion is not
practical. For extremely greasy or dirty steel parts a preclean in a solvent vapor bath
using Perchloroethylene, or hand wipe with QSOL 220 and air dry may be used on a
limited basis.
If a solvent vapor bath is selected, a degreaser which incorporates a spray flushing
nozzle must be utilized except for specific parts noted herein. Clean steel parts by:
a. Immerse parts in a solvent vapor bath for 3-5 minutes to loosen all dirt, oil and
grease.
b. After vapor bath, spray all holes, cavities, and recesses with clean liquid solvent
from a pressurized nozzle to thoroughly flush and remove any debris.
c. Air dry thoroughly using filtered, dry, compressed air.
d. Wrap parts in clean paper or hang from racks to retain cleanliness until ready for
priming. Do not touch parts with bare hands until primed.
3. Application
Apply primer after mixing per manufacturer’s recommendations. Total primer coating
is not to exceed 0.005 inch thickness. For parts with internal openings, such as tubes,
prime the inside as follows:
a. Thin primer to watery consistency using required reducer.
b. Pour in primer, slosh around, then drain immediately.
c. Dry parts at least (6) hours before using.
4. Inspection
Inspect for complete coverage and excessive thickness. If primer is excessively thick,
strip part using plastic media blast and re-prime.
Page 20.14 Chapter 20 Standard Practices R66 Maintenance Manual 25 OCT 2010
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