Clean, Confident Aluminum Body Repair

Customer Challenge: Since aluminum does not rust, why is corrosion protection still important?

Technical Tip: Aluminum naturally forms a very thin layer of oxide on its surface. This layer (normally just a few hundredths of a millimeter thick) tends to impede the adhesion of coatings, such as seam sealers, fillers and primers, and can cause them to peel. Therefore it is very important to completely remove this layer of oxide before applying any auto repair coatings. Also, this oxide layer is self-healing, meaning it will quickly reform after it’s been removed. You should always apply coatings to abraded aluminum surfaces no more than one hour after the oxide has been removed. Otherwise, you must re-abrade the surface.

Customer Challenge: What is galvanic corrosion, and why should I be worried about it?

Technical Tip: Galvanic corrosion occurs when two dissimilar substrates, such as aluminum and steel, come into contact. Each substrate has a natural electrical charge. The substrate with the higher electrical charge (aluminum) will always start “donating” electrons to the lower-activity substrate (steel) to achieve a natural balance. This results in the aluminum corroding and falling apart over time – leading to blistering and other paint failures in aluminum vehicle repair.

You can help prevent galvanic corrosion by ensuring all substrates are properly cleaned before coatings are applied.

Customer Challenge: Is it possible to create a true “clean room” for aluminum repair in the body shop?

Technical Tip: Even if you completely segregate your steel and aluminum repairs, it’s unlikely that you can achieve total separation. It is vital to examine your overall shop hygiene. Establish regular cleaning protocols to maintain shop cleanliness, especially for dust – you should always assume that some dust particles will inevitably settle on dissimilar panels. Self-generated vacuum tools can also be used to keep the dust particles to a minimum while keeping equipment spends down. Never use the same tools or abrasives for both steel and aluminum repairs, and clean your tools regularly. Incorporate procedures for cleaning vehicle panels immediately before applying any coatings.