On Wed, 30 Aug 2017 21:27:09 -0400, wrote:

On Wed, 30 Aug 2017 11:20:00 -0400, "Jim Wilkins"
wrote:

I have a persistent rust problem on the lower edges of rear fenders
where the wheel well liner blocks access to the back side. The lower
edge seam wasn't watertight and rust has perforated the outer and
wheel well liner sheet metal below the factory sealer bead, which was
applied from inside after spot-welding and didn't reach down to the
joint. I dug out most of it so I could MIG weld patches without
igniting it.

Several local paint suppliers have suggested 3M 08852 Cavity Wax Plus
to coat the inside of my larger welded and smaller resin patches to
prevent or slow the so far yearly rust lines along their edges. LPS-3
wasn't up to the task, or I didn't coat the out-of-sight area well
enough with it. The Cavity Wax comes with long applicator tubes.

I'd like advice on if it really works, and how difficult it is to
remove if for some reason it doesn't and I need to weld in a larger
patch.

The clerk told me it's better than rubberized undercoating in the
wheel well. The suggested alternative there is spray can truck
bedliner, assuming it can be removed if necessary.
tia
-jsw

If you don't get ALL of rhe rust out, it WILL come back - but a
Wax-Oil reatment will drive out moisture and seal moisture out - doing
a pretty good job of reducing rust. Bedliner just locks in any
moisture amd lets it rot from behind leavinf you a plastic fender.

How well does phosphoric prep/etch/rust-converter work in this
application?

-
I am a Transfinancial--A rich person born in a poor person's body.
Please stop the hate by sending me money to resolve my money
identity disorder. --anon