Rust repair before paint, The quest for solid metal in the driver side Long - 73 narrow body/4 rebuild thread Options

[Montreal914]

Edit: I might as well make this my rebuild thread...

Original post; I got side tracked on my Microsquirt build as I have decided, after 11 years of ownership, to finally get my car painted to get her ready for her upcoming 50th birthday. (IMG:style_emoticons/default/smile.gif)
Knowing these endeavors can take a lot more time than initially planned, I hope to make it in time... (IMG:style_emoticons/default/wacko.gif)

Originally bahia red 73 1.7. The goal is a narrow body 2056 Microsquirt, VW Tornado red, 5 lugs conversion with 16" Fuchs.
Front: 914-4 A arms with rubber bushings, 911 3" pin struts, Bilstein inserts, Alfa Brembo, vented rotor, stock torsion bar, 19mm sway bar, turbo tie rods, and 19mm master cylinder.
Rear: Drilled hubs, 914 PMB stock calipers edit: 914-6 calipers replica, 914-6 solid rear rotors, 140lbs springs, stock sway bar, rubber bushings.

But before I get the pleasure of installing all of these beautiful fresh goodies, I need to tackle the not so fun stuff... (IMG:style_emoticons/default/headbang.gif)

I have already started fixing some of the rust issues and will share that progress in the near future but right now, I wanted to post some of the issues i have on the passenger side front fender. (IMG:style_emoticons/default/sad.gif) I have searched and read many of the builds here but I would like some inputs from the people who have gone through this mess.

I am trying to understand the construction of the rear part of the fender, more precisely the area joining the front cowling.

Below is a sketch of how I think it is made but i would like someone to confirm...



Having removed the seam sealer in the upper rear area, I have discovered "this" (IMG:style_emoticons/default/dry.gif) which is not really unusual, but clearly a pain to fix. I am not sure though what I am looking at. If my sketch is correct, I guess the inner rusted layer is from the fender rear bulkhead that actually becomes an inner layer on the rear upper point of the fender by the door and cowling junction.





I might be able to cut this from the underside preventing me from cutting the outer surface of the fender. But I would like to better understand what is happening at the junction to the body.
How many layers are there from the fender, one or two?
Is the metal peeling off at the joint to the body the metal from the bulkhead/inner layer, or is it the outer fender layer?

As a reference, this if the situation of the channel, surface rust, but how bad? Is there a way to better know without destroying? Maybe poke with a screwdriver? (IMG:style_emoticons/default/confused24.gif)



Comments appreciated (IMG:style_emoticons/default/smile.gif)

[nathanxnathan]

Coming along nicely. (IMG:style_emoticons/default/smile.gif)

I'll have to take another look at the back of the trunk seal area to see how that ties in with the rear panel above the tail light.

Other areas to think about... the bottom of the door jamb, how to tie that to the sill. The factory I think gas welded that joint with bronze, as there's an overlap of the 2 panels.

The top of the sail panel where the flange goes I think under the top of the targa bar. Plug welding that seems like the best option. It's a tricky area because you can't back the weld.

The other area to think about is the fresh air inlet. The ones I've seen, the factory mig welded the lip of the 2 layers. I've removed one, and was able to just grind off the lip/weld and carefully separate the tube inner from the flanged hole in the inner fender.

What are your thoughts on prepping the inner fender before mounting it? Areas like behind the sail panels or the area where the foam is at the rear of the fender by the tail lights aren't going to be accessible once the fender is in. The factory I think there's just primer there.

I've thought about this for my front cross panel project on my car. My thoughts are 3M Weld Thru Primer on both surfaces of the seams where it'll be spot or plug welded. ... tape off the flanges that will be welded, epoxy primer, then tape off and spray weld thru primer on just the flanges — seems like the best way. I'm not sure what others do?