Conversion coating is a toxic chemical and requires use of rubber gloves by personnel during
its application. If acid, accidentally contacts the skin or eyes, flush immediately with plenty of
clear water. Consult a physician if eyes are affected or if skin is burned.
Do not permit Specification MIL-C-5541 material to contact paint thinner, acetone or other
combustible materials. Fire may result.
Mix the solution in a stainless steel, rubber or plastic container; not in lead, copper alloy or glass.
Mix in accordance with manufacturers instructions.
Apply the conversion coating (light) by using a fiber bristle brush or a clean, soft cloth. Keep the surface
wet with the solution until a coating is formed which may take from 1 to 5minutes depending on the surface condition of
Do not permit excess conversion coating to dry on the metal surface because the residue is
difficult to flush off with water.
Rinse with clear water, or sponge the area with a clean, moist cloth, frequently rinsing the cloth in clear
water. Thorough rinsing is required.
Allow the surface to air dry. To speed drying the surface may be blown dry with warm clean air (140
Avoid brushing or rubbing the newly applied chemical conversion coating, since it is soft and
can be easily rubbed off the surface before completely drying.
Any absorbent material used in applying or wiping up MIL-C-5541 material shall be rinsed in
water before discarding. They are extreme fire hazards if allowed to dry otherwise.
A light Oust visible to the naked eye) evenly dispersed conversion coating is all that is
required. It is recommended that a test panel be prepared and subjected to complete
cleaning/treating procedure before applying material to a sheet. The test panel shall be used
to determine the dwell time of MIL-C-5541 material. When clear material is being used, no
control of discoloration is necessary.
After the procedures cited in paragraphs 3-252 through 3-263 have been complied with, an AF
Form 50A will be attached to each sheet with a statement that, "This material has been
cleaned and treated for corrosion IAW T.O. 1-1A-9 Section III, date..." If original markings are
removed as a result of the cleaning and treatment process, the material shall be remarked
(staggered) at each end and in the middle with the Specification, size/thickness, temper and
type or grade. The marking may be applied with Black paint Specification TT-L-50, MIL-B-7729
or Magic Marker" manufactured by Speeddry Products Inc., Richmond Hill, N.Y. or "Equal".
A felt tip pen may also be used.