Summary for corrosion protection for 6061 aluminum Discussion
Corrosion protection for 6061 structural aluminum is the main concern in this thread: Bob Singer asks how to finish a large welded-and-fastened box made from 6061 channel and I-beams for a salty ocean environment, after soda blasting, with anodizing ruled out because of size. He says Alodine seems possible but he has seen conflicting recommendations, and powder coating is available but not his preferred choice. The excerpt does not include any replies, so no consensus solution is shown in the source provided. The practical takeaway from the question is that the finish must be suitable for severe marine exposure on a very large assembly, and the user is specifically weighing conversion coating versus powder coating after surface preparation.
April 15, 2014
Q. Hello,
I am looking for a solution for the final protection coating on a structural box made of Aluminum 6061 structural channel and I-beams. The box is large 12 x 8 x 8 1/2′ tall. The destination is in a slat environment near the ocean. We built the box using std structural brackets and huck fasteners. All is assembled and out for soda blast to remove the mill finish and markings.
The question is what is recommended to complete this for best corrosion resistance ? Anodize is out of the question due to size. Alodine is there, but I see conflicting recommendations. Any other ideas would be appreciated. Powdercoat is possible but not the favorite answer …
Bob Singer
Design Engineer – Stuart, Florida – USA