if that can help you with an easy and quick fix which is not esthetical, but effective to stop the spreading and ''stealth''. Used it at several places around my windshield and the rear window. Around the windshield, it was not rusting enough as to have leaks already.
I cut a portion of the rubber trim at rust location
Carefully route-out the rust until I get to healthy steel and most rust humanly removable. You can use a dremel. Careful not breaking the windshield. That will create bigger holes than you tought, because the rust goes farther than you can see outside.
clean throughouly with a solvent
patch with epoxy (can use jb-weld, or any reinforced epoxy, these are the most protectant against future corrosion) and fiberglass.
Do not use putty, we don't care, we have trucks with experience and a hard life. Sand to a roughly good result and clean the area with acetone.
mask using 2" tape all around the repair area. Apply preferably epoxy primer (expensive, so do all the places at once). Let dry.
Apply basecoat.
Unmask and let dry.
Mask 0.1" outside old masked area, apply clear coat.
Let dry, apply masking tape to build your false rubber trim. Use black silicon or eurethane and form. apply with finger, remove tape and let dry.
Nobody will notice at 10 feet.
If you do all the spots at once, you'll have to buy one can of primer, epoxy, base coat (which can serve for the rest of the life of the truck for touch ups) and clear coat. Important to use a 2 part clear coat like these
2 parts can
I have spots done since 2015 in salty canada, which have not even needed a touch up since.
