Marcel, great to hear on vinegar and wonderful pictures. I've heard a number of good reports on vinegar on the AMCA and CAIMAG discussion boards.
your pictures of the results are very appreciated.
also heard molasses works well. never tried vinegar or molasses. but SEEING your experience will get me to try vinegar.
i have been using a product called "Metal Rescue," not an acid product, which works very well but is $25/gallon. Vinegar is inexpensive !!
after using rust remover, i put 50 8mm bolts in my tanks, rotate then in clothes dryer for 50 minutes and beautiful raw steel is exposed.
Great report and pics using fiber optic scope ?