panel skin concern

[danp76]

How many of you guys during a restoration of a door or trunklid remove the folded hem on the jamb side for sandblasting/rust treatment purposes? I was thinking the last few jobs I just sandblasted the panels, used epoxy, and seam sealed where the hem folds into the jamb side...what do you guys do? Is there a large concern for rust formation under them hem, and rusting from the inside out?

 

[crashtech]

In theory, we'd like to completely disassemble the vehicle, think of all the spot welded flanges that don't get corrosion protection. In practice, it's not very practical. I don't know anyone who would do that just as a protective measure, nor have I ever removed a door skin carefully enough to re-install it, except in a repair area like a mashed corner. Have you?

There is an outfit that will acid dip your vehicle, then dip it in e-coat. This is the only way to really achieve what you are talking about without causing a lot of damage to the vehicle.

 

[Senile Old Fart]

This is along the lines of the same thinking I expressed about inaccessible rust and possibly using a chelation process to strip it. No neutralization would be required with chelation. Once rinsed and dried I would think that thinned epoxy sprayed drenched dipped whatever into these areas wold seal them well.
My other thought was citric acid, which is an easy to neutralize acid, a good soak / with Purple Power will take care of it, much the same process as cleaning soda blasted metal before epoxy If I understand correctly.

 

[danp76]

I have had parts chemically dipped before, for a t-bird restoration, but it took some time to get panels back, and a lot more expensive then sandblasting.

 

[Bob Hollinshead]

On the tightly folded seams even dipping won't get the corrosion out-I've opened up some of these after the dipping process and the rust is still in there. If you can open up the seams some before dipping the rust will come out. Also remember on most hoods and decklids there is antiflutter foam spots/glue spots between the inner structure and the outer skin and the dipping will remove these-this can create some headaches on a panel you need to have perfectly straight. I really like to reskin doors so I know they will last. On doors that won't be skinned-if they show any corrosion along the edge of the seam I open the seam up and sandblast it, when the seam gets closed back up I tape the seam or seam seal it and tape the drain holes shut and pour in some epoxy primer-just enough to fill the seam, when all the paintwork is done I treat the seams with cavity wax or cosmoline. A properly installed doorskin will last forever, factory installed doorskins usually started rusting before the vehicles are delivered new-I've opened up quite a few new lot damaged/transport damaged doorskins that had rust in the seams from new. The factory bonded doorskins aren't showing much more longevity-the factory often does a hit or miss application of the glue and leaves a spot for corrosion to start-or the door gets tweaked and the bondline cracks making a spot for corrosion the form.