I am about to start the body work on my 72, the front fenders are in primer (I have no idea what kind of primer)I am going to sand them down to bare metal. My question is what do I do to the back of them? Stip, if so with what?

i didn't strip the back of my fenders....i just sprayed some POR right over the old paint. hasn't rusted so far and the wheelwells cover up the back so you can't see it. my .02
-Jay

If they are re-pops that black coating can be sanded and covered with paint. I painted mine the same as the exterior. The reason was I am very anal, the 2nd I needed practice with the BC/CC. A good buddy of mine coats them with rubberized under coater.

The fenders are not re-pops. Would it be ok to shoot them with a sealer and top coat?

Originally posted by Professor_SS:
A good buddy of mine coats them with rubberized under coater. That is what I did...Actually, what I did is mask off about 3/4 of the fender, and undercoated the bottoms of them, where the usual rust pucker starts (eats through)with a rock or something. Kind a like a new car "rustproof" coating on the lower parts of the fenders, if you will. I couldnt see undercoating the WHOLE thing, but I'm glad I did the lower area.

I would recomend that you clean off the inside of the fender's to bare metal using a 3M stripping wheel and then prime and/or paint & undercoat.

The 3M wheel won't generate much heat and clean it up very nicely, including the surface rust. The old undercoat will be pretty dry & useless and the paint/primer that is on there isn't "prepped" to the metal so it is just an ineffective coating.

Then I would top coat it with POR-15 Satin (2 coats). POR needs to be in contact with bare metal/rust otherwise it will serve only as a regular (very expensive) paint and it's rust preventative qualities will be wasted!!! Alternatively, you could prime with a self etching epoxy primer (Rattle can ok) and then topcoat it with whatever you choose.

Once thoroughly dry (96+ hrs) then spray in some 3M Rubberized undercoating, avoid the asphalt undercoat. The asphalt stuff dries out fast and is heavier than rubberized.

I always undercoat individual panels like fender's to reduce noise and to help protect from stones and other debris. NOTE: On inside panels such as the doors, quarter panels etc... use 3M Inner Panel Coating for protection. This can be sprayed in regardless of what's in there as it will "seep" into nooks and crannies. The inner panel coating will not hold a topcoat so don't use it in your trunk or other areas that will be topcoated.

3M Strip Wheel Info (http://products3.3m.com/catalog/us/en001/government/innovative_solutions/node_GSSHVZ2FZ6gs/root_GS3RBW6QFVgv/vroot_31S2JJ7584ge/bgel_P2K64ZB62Xbl/gvel_9PGQKXP0K1gl/theme_us_innovativesolutions_3_0/command_AbcPageHandler/output_html)
3M Undercoating Info (http://products3.3m.com/catalog/us/en001/government/innovative_solutions/node_TP67DR23D2be/root_GS3RBW6QFVgv/vroot_31S2JJ7584ge/gvel_FBGPSP8WSSgl/command_AbcPageHandler/theme_us_innovativesolutions_3_0)

Hope it Helps.