Ran a quick test to see if my new marking system would survive the acid- alodine. With the main spar I used a magic marker and a lot of effort to redraw ink after each process. This is my plan for parts for the rear spar. I buff a small area - and clean with acetone - on parts that I want to mark. I paint the lettering that at this point only exist as a felt marker. The part is then placed in the acid bath - alodine cycle. I found that the alodine markings survive the acid bath. They also are visible thru after the real alodine dip. I try to put such a thin coat of primer on that the markings should still be visible thru the primer after drying. ALODINE �� ALUM COND 1201-GAL 1 $44.83 $44.83 07/27/18 http://www.wicksaircraft.com ALUMIPREP **HAZARDOUS** 33-GAL 1 $36.89 $36.89 07/27/18 http://www.wicksaircraft.com CHEMICAL