My company deploys equipment housed in an enclosure that is located in a mild salt-spray environment but no sun/UV exposure. Now we are using stainless steel but we need better heat conduction. Can we use aluminum enclosure? Painted? Coated? Z. K.
Absolutely! The British Navy built destroyers having aluminum superstructures. The salt-laden ocean breezes did not harm them. However, a cruise missile nearly burnt one of them in half during the Falkland Islands War. Therefore, I can’t promise you protection against cruise missiles, but I can promise you protection from a mild salt spray atmosphere. Pretreat the aluminum using a two-part vinyl wash primer or an inorganic conversion coating for aluminum. To the pretreated aluminum, apply a robust finish system such as a two-part epoxy primer topcoated with a two-part polyurethane or a urethane acrylic enamel. Although this is a fairly expensive finish system, it may still be less costly than using stainless steel for your enclosures. You must do the math. Suppliers of these finishes are listed in the 2005 Products Finishing Directory & Technology Guide, under Coatings, military and government specification and Coatings, plural-component (www.pfonline.com/suppliers.html).