Advice needed on cowl-fender repair areas and rust in welds Options

[doug_b_928]

After no progress in 2022 due to other time commitments I'm ready to get back to my restoration. Most of the rust repair on the middle and rear of the tub is done, but I still have the front end to do. I'm at a crossroads with respect to the cowl-quarter channels.

It's very difficult to see and even more difficult to get good pics but the right side channel has some spots where it has rusted through. Here are some pics:





But the underside looks great to me. Here's pic of the underside which I cleaned up, rust treated, and epoxy primed several years ago.



The left side fender-cowl channel is in better shape when looking down into it. Here is a pic:



I removed most of the seam sealer from the underside but still need to clean it up. As shown in the pic below, there is a spot of rust but it does not look like it has rusted through, so I expect this side to clean up as nicely as the right side.



So, question #1 is how to deal with these areas. There aren't many threads that deal with their repair but having studied the ones I could find I think I have a good sense of how the two pieces are welded together. It looks like it might be difficult to remove the spot welds in the door area. I believe I can do it but I'm wondering if wire wheeling, treating with metal prep, epoxy priming and then seam sealing might be what's best in this area. Obviously best is always to cut it out and get rid of any sign weakened metal but then getting the panel to look as good after the repair might be a challenge and since this location is kind of buried maybe it's better to leave the nice lines on top and treat it. On the other hand, if it's going to be an issue in the future then I'd rather cut it out and repair now. So this is the conundrum. What say the brain trust?

The top side of the cowl is in nice shape and the channel for the windshield has some pitting but not perforation. I still need to take a wire wheel to the windshield channel. Here are some pics:





Unrelatedly, one benefit of taking forever to do the rust repair is one gets a chance to see where rust wants to rear its ugly head again. There are 4 spots where I can see some rust on the epoxy primer. Two of them are on the left suspension console where I did the 'weld little rust areas with the mig' techniqe. Here are pics of those:





And the other two are seams where new metal was welded to old. One is on the rear trunk floor crossmember and the other is below the right rear tail light.





So, Is this a matter of some rust mixed in with the weld or is that there was still rust behind the area that needs to be dealt with?

[doug_b_928]

Thanks for the replies. For metal prep I'm degreasing then using POR Metal Prep, letting it dry over night, and then epoxy primer. It appears to have worked very well except in the spots I've pictured. I'll remove the epoxy and get a better look at what happened; cut and redo if necessary.

The big question is what to do about the fender-cowl area. Montreal914's repair looks thorough and nice. In my case I don't see a need to replace the cowl and my quarter isn't rusted through like his was. So it makes me wonder what is the best thing to do here... There was no rust bubbling on top or bottom in this area, it seems to be just in the channel so I'm wondering if treating and epoxying will do the trick and it might never be an issue...

Montreal914 has linked his thread which is excellent. The only other one which is also excellent at showing how the panels connect is here: http://www.914world.com/bbs2/index.php?showtopic=110572. It has links to some others as well. T