SSPC-SP 16 Brush-Off Blast Cleaning of Coated and Uncoated Galvanized Steel, Stainless Steels, and Non-Ferrous Metals
Nonmandatory Appendix A: Explanatory Notes
Brush-Off Blast Cleaning Aluminum, Copper, Brass and Stainless Steel:
Brush-off blast cleaning may not remove stains that could be detrimental to a paint system. If stains are still present after brush-off blast cleaning, they should be removed by spot cleaning, power brushing, or orbital sanding using stainless steel wire brushes, or stainless steel abrasive pads, followed by repeat brush-off blast cleaning if necessary to provide the desired profile. When brush-off blast cleaning aluminum, the protective oxide layer is removed. A high performance coating system will improve the corrosion protection of the metal. Additional information on the preparation of aluminum and aluminum alloys for painting can be found in ASTM D 1730.
SSPC: The Society for Protective Coatings, http://www.sspc.org/ST-00SP16
ASTM D1730 Standard Practices for Preparation of Aluminum and Aluminum-Alloy Surfaces for Painting
These practices cover four types of treatment for preparation of aluminum and aluminum-alloy surfaces for painting, as follows:
Type A—Solvent Cleaning.
Type B—Chemical Treatments.
Type C—Anodic Treatments.
Type D—Mechanical Treatments.
These four types cover a number of procedures, as described herein.
ASTM D7091 Standard Practice for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings Applied to Ferrous Metals and Nonmagnetic, Nonconductive Coatings Applied to Non-Ferrous Metals
For gages measuring on non-ferrous metals, the gage probe is energized by alternating current that induces eddy currents in the metal substrate. Note that gages/probes for measuring coating thickness on non-ferrous metals should not be used to measure coating thickness on ferrous surfaces, even though a reading may be displayed.
ASTM International, http://www.astm.org/cgi-bin/resolver.cgi?D7091
2015 Aluminum Design Manual FAQ
Is it acceptable to place aluminum in contact with concrete?
The 2015 Specification for Aluminum Structures Section M.7.3 states:
“Aluminum surfaces shall be painted if they are to be placed in contact with concrete or masonry unless the concrete or masonry remains dry after curing and no corrosive additives such as chlorides are used. Aluminum shall not be embedded in concrete with corrosive additives such as chlorides if the aluminum is electrically connected to steel.”
https://www.aluminum.org
Galvanic Corrosion
Galvanic corrosion (also called ‘ dissimilar metal corrosion‘ or wrongly ‘electrolysis’) refers to corrosion damage induced when two dissimilar materials are coupled in a corrosive electrolyte. It occurs when two (or more) dissimilar metals are brought into electrical contact under water. When a galvanic couple forms, one of the metals in the couple becomes the anode and corrodes faster than it would all by itself, while the other becomes the cathode and corrodes slower than it would alone.
NACE International , https://www.nace.org/resources