Fender channel help

dbittle said
View attachment 1716103368
What does everyone do with this channel on the back of the front fender? I know it is rusty inside. I think it has two spot welds at the bottom and fits under the lip of the fender. Thanks much for any advice from the more experienced people !

Well what I did was clean up what I could and then used Por-15 prep witch is an acid and zinc phosphate and got that behind there and then poured Por-15 primer in there and and soaked the **** out of it and made sure it coated both sides of the inner structure and wasted a bunch of material but was worth it.

Sanded it after this and used truck bed liner after the Por-15