Touch-N-Prep Alodine 1132, manufactured by Henkel Surface Technologies, Madison Heights, Michigan. The pen is a special felt tip marker that contains the Alodine 1132 conversion coating solution and works like a highlighter pen, making it very user friendly (See Figure 1). The pen has several noteworthy advantages over the other application methods such as spray, brush, and immersion. Conversion coatings are important and serve several purposes. When the conversion coating solution is applied to aluminum, it converts the oxide on the aluminum to a chromium/aluminum oxide. This newly formed chromium/aluminum oxide layer provides increased corrosion resistance and improves paint adhesion. This oxide layer also provides a conductive corrosion resistant film for electrical bonding and grounding applications where low electrical contact resistance is required.
MIL-DTL-81706 covers the requirements for the chemical materials used in the formation of conversion coatings by the reaction of the material and the surfaces of aluminum and aluminum alloys. This specification does list the applicator pen as an option under methods of application. MIL-C-5541 covers the requirements for chemical conversion coatings formed by the reaction of chemical conversion materials (MILDTL-81706) and the surfaces of aluminum and aluminum alloys. Conversion Coating, Brush and Spray, is also important. This specification establishes the requirements and procedures for conversion coating metal substrates with chemical conversion materials in accordance with MIL-C-5541. PS 13204 has recently been revised, and is approved, to add the Touch-NPrep Alodine 1132 pens as an option to apply conversion coating solution.