Because the trim tab is already bent it’s to narrow to spray primer in the inside for corrosion protection. Although I don’t like working with hexavalent chromium, I decided to treat the trim tab with Aluprep 33 and Alodine 1201.
I purchased 1 quart of Aluprep 33 and Alodine 1201 from Aircraft Spruce in Germany and used 75 mm pvc pipe in an extra 110 mm pvc pipe as containers.
I used this procedure:
– 4 minutes in Aluprep
– 4 minutens in Alodine
Important note with these horizontal containers is to stir before use!