Rust Blast (post treatment-acceptable amt of surface rust)

[Joehd8811]

Going through with sealing a motorcycle tank. Spent two and a half days starting with the stripper to remove an old patch job and meticulously cleaning and using the rust blast. 

 

I just got done the rust blast, and immediately force dried it. (Blew out as much as possible with compressed air and then a heat gun on low fan for an hour or more)There is some light surface rust which in the instructions states is normal. Although in one corner where some of the rinse water puddled before it dried left a heavier spot of surface rust. 

 

I tried getting the best pic I could, am not sure if this is ok or not. I spent so much time prepping to the directions I don't want to move on to the sealer unless I'm confident. 

[KBS Coatings]

It looks like the rinse water after RustBlast puddled there and possibly that this section did not get rinsed as well as the other surfaces.

 

Can you get a wet rag in there and rub the surface to remove the excess zinc phosphate and then dry that area immediately?