I have been working on the rear of the car. I replaced part of the wheel arch, inner and outer sections of the bottom of the rear wing and part of the valance.
I have however been left with a collection of pin holes in the weld I am struggling with. All looks good after a lot of work. Just to test water tightness I squirted some panel wipe from the inside down the small access gap left under the petrol filler pipe section.
1.About four tiny ones on the butt welded seam for the outer lower panel repair.
2. Some where that repair joins the inner valance.
3. Some leaky seams where the inner and outer join near the bumper mount.
I have had a couple of goes at it now and made progress but every time a weld a hole and grind down again I am thinning the metal. I fear the more I try to fix it the worse I will actually make it in the end
I can use seam sealer on area 3. There is no access to get seam sealer inside for areas 1 and 2 from inside.
I am thinking perhaps use an extension hose and blast a load of over paintable underseal in. Problem there is I just end up potentially creating a water trap.
Or in the end does it really matter? The inner closed section is hardly going to get water inside to attack the filler from behind. I have good Rage Gold quality filler that has some water resistance (so it says on the tech sheet)
I think that depends on whether and/or how often the car will get wet.
Since I restored my MKII in 1990, the car has gotten wet twice. Both times when I washed it. It has never been driven in inclement weather, nor even over wet pavement. Now, I’ll admit, in sunny Southern California, that’s not a difficult feat. But my point is, if it won’t get wet, I wouldn’t worry.
I have had difficult repairs like that, and I do think you have to address the rear of the weld, as they will eventually rust back through just from moisture in the air…so I drill access holes, and use rust retardant sprayed in.
Of course the outside needs attending first, and I use a 2pack paint system on the bare metal asap
Finally after several long frustrating sessions I managed to seal the panel. The original metal was thin and then the grinding made it worse so I ended up blowing lots of holes… and having to start over.
There is enough access to get the lance of my cavity wax in