Painting & Metal prep questions

[Blue666(2)]

I'm trying to prep the backs of my fenders, inner fenders and some other sheet metal to protect it long term. These are the surfaces that are not seen from the outside.

Can I OSPHO these rustfaces and slather with rustoleum or another protective paint. After I reassemble the truck, I don't want to have to address rust from the backside for a long time.

Are there any better options?

[hugger6933]

They we do it on the left side of the river is to prep and paint the inside of the fenders just as you would the outside. Some folks may consider that a little OCD or too much of a late model look but I'm so use to doing it on the late models I build that it looks good to me that way and it really does look good under hood of a truck that is color keyed underneath kinda like the late model trucks are.
Now as to the prep, if the panel is new you can do a rag test witch is put some lacquer thinner on a rag and wipe on the part if it comes off black you need to sand and prime it if not you can feel secure that the part has been EDP primed instead of just cheap black primer as was the older practice. I hope this helps you out figuring what to do. Jim

[kaycee]

I was wondering the same thing the back side of my fenders and inner panels are kinda rusty. THese are original panels ,was going to squirt them with prep & etch then squirt some zero rust on them.

[hugger6933]

In my first answer I approached the panels as if they were new in this one I will as if they are good panels that came on the truck40 whatever years ago. Most of the paint will still be in pretty good shape and hit it wit some say 220 grit paper. That that isn't lets go down to a heavier paper say 120 or even 80 grit then see if we can take care of that rust by mechanical means. If not or there are spots that cannot be reached then you will want to spray some sort of treatment on it to convert the rust into a primer of sorts several companies make it Eastwood being one on the forefront. Once that is on, I would if the tech sheet from the rust product allows, put a couple a coats of high build primer over the top of the rust converter then the color I planned on using the high build will help so much in the little places that just need the extra help.