Guest User
If using galvanized, painted panels, is it ok to use aluminium coil stock for trim work? Would using the dissimilar metals cause problems later? What about fastening?
Todd Miller
Isaiah Industries, Inc.
In the case of dissimilar metals, there is a risk that one metal can sacrifice itself to another, resulting in corrosion. The potential for this to happen is exacerbated by moisture and also by coastal (salt) climates. That said, though, keeping the metals separate helps to avoid this situation. In this case, chances are that both your steel and your aluminum have paint finishes which would help insulate against galvanic corrosion. Additionally, your steel has the galvanized coating on it. The galvanized coating is a combination of zinc and aluminum which is reasonably compatible with aluminum. Wherever possible, if you can provide additional separation between the metals, that would be an extra safeguard. You could do that through the use of felt paper, sealants, or other materials. If you have fasteners which must go through both the steel and the aluminum, I would suggest either a stainless steel fastener or a high quality hot-dippped galvanized fastener.
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