FV interior stain
Hey all, I am doing an initial clean on my new fv's and one has an interior stain on the side wall the was there during shipping. It looked like rust. When I hit it with caustic 2oz/gal and hot water 170 for 70 minutes it cleaned the rust off, but not the underlying stain. I am going to hit it with my acid regimine right now, but I have an obvious concern. Have any of you had an experience like this? Advice?
Try nitric acid to remove any residual rust and re-create the protective oxide barrier. Warm generally works more effectively than cold. Concentration ? Not sure off the top of my head, but dilute, not concentrated.
There has been at least one thread on passivation of new kit.
If the vessels are not too big, it would be worth a close visual inspection of the welds and surface before and after.
I have no experience of Chinese stuff, but there have been a number of questions being asked about the quality of the stainless, and the tendency to rust, even after passivation.