I've stripped the original paint from my 71 coupe 360* around the body from the fender crests downward. Upper portions and doors will be done later.

I found two areas that may need extra attention and I hope somebody here will be able to help...

The first is about a quarter sized area near the back of the RR fender:


Questionable area is above the build out for the rear bumper mount



Closeup of the ying & yang looking area. I think part of a bonding strip is behind this area but I don't know if that's related to this ??? that is just forward of the bonding seam.



There is no such "marked" area on the other rear fender


Any ideas what this is or what caused it? Is there anything special I should do before painting to ensure it isn't visible or cause future problems?



The second area is some sort of chevy dealer repair that was done to the seam area above the wheel on that same fender.:


Here is the fender's repaired area



From the bottom the layers I THINK I see are red/brown primer, fiberglass, primer, blue paint, bondo or some other coating, fiberglass, primer and finally paint again on the top. Does that look/sound correct to you?



A bit more sanding revealed these X and + " stitching" marks that also were previously showing through the paint. Anybody have a clue to what these are??



Close inspection of a + mark looks like it MIGHT be some sort of heat tool mark like something heated & melted into the bonding adhesive or the glass itself to hold the panel edges together. Is that even remotely possible?


Any help identifying these repair marks and how to deal with them so they don't reappear after repainting would be greatly appreciated by this novice!!!

Thanks

 

Those look like previous repairs like you say. Probably a previous owner backed into something on the earlier pictures and produced cracks around the bumper area and opened up a hole. The over-fender repair ...someone probably backed out and caught the side of the garage opening ...or something pushed in the side of the fender above the wheel, and 'tweaked' the bonding seam area. And that's what the repair is over that area.

I would start by looking closely at the back-side of those areas. See what if any damage looks like back there. Then assess what the next steps would be if it looks rough (like backside repairs). If it looks good on the backside, I would at least V-out the cracks by the bumper mount and re-glass (with resin and fiberglass strand) in those areas, and sand that down to match the opposite side of the car. Same thing if the bumper mount hole needs to be closed-up a little (glass it closed a little and file it the size it needs to be).

The quarter-sized repair area, if it's smooth, and backside looks fine, it can be primed over as-is. Should be fine. A guy can do any bodywork now over the bare fiberglass (if needed) or do it over primer ...after it's primed ...however you choose. You'd want a filler that was for applying over 2k primer ..which most good ones are. I always sand the primer anyway with like 80 or 120# before applying filler over it. Wash the primer off (to remove all dust for best adhesion) ....and THEN apply the filler, if you are applying over primer ...to give the filler some scratches to 'bite' to. Or, as I say, you can do your bodywork straight on the fiberglass ...if any further bodywork is needed.

Are you going to strip the rest of the car for a repaint? Or what's the plan there?

.

 

I do plan to strip the whole car for a repaint. It only has/had the original Mulsanne Blue paint from 1971. I had been using the Cooper's Stripper product but ran out and can't get more in the U.S. because there's methylene chloride in it. I just got some Dumond Smart Strip Marine and will try that out to see how well it works.

One question (of many) I have is how far do I have to go? The single layer or original paint is coming off fairly well, but there's still a good amount of the red oxide? primer left. Does that need to be stripped or sanded down to bare fiberglass or can I prime and paint over that remaining original primer?

 

As for that old passenger rear fender repair, I've sanded off more of the old filler? and taken more pictures. Hopefully I can get some guidance on what was done and how I should proceed...


Ended up finding 5 of these "stitches" just below the fender seam line.



Closeup of the stiches



Another closeup



Filler to the right (forward) of the stiches



More sanding of the old filler exposed some original paint beneath. I guess that means the paint wasn't even removed before the filler was applied right over it.

My plan was to dish out all the body bonding seams and fill with VPA to hopefully prevent them from telegraphing through the paint like before.


Visible seam line on front right fender

Now I'm worried that when I go to dish out the seam and area around the right rear stiches, the fender seam might open up again. From inside the wheel well, the bonding stip looks OK, but there was evidence of fiberglass cloth being used on the back side of the repair area. I removed that and re-glassed it with matt about a year ago.

Sure wish I knew how those "stiches" were utilized/made for the repair!

 

I don't think you need to worry about the bonding strips telegraphing through if you use 2k primer. Assuming the bonding material is still good and not cracked. Part of the problem was the older lacquer primers which were thin (and so guys would lay on several coats to build up) ...and they would eventually shrink some letting imperfections below telegraph through (and that includes sand scratches and bondo lines ...on any vehicle back in the day). And the other part was probably the bonding material itself that shrank some over the yrs. But by now it should be good. But you could add a small layer of glazing putty on the seams and sand down thin if you wanted to.

But when the day comes to prime your car with like a 2k or epoxy primer, let the primer sit a week to fully cure and shrink out before you 'work' it.

As for the crosses, I haven't seen them before, hopefully someone will provide an explanation. The only thing I can think of is it may have belonged to a certain group of aliens which went by the cross marking. Just kidding. But just as with the bonding seam line, I doubt they will telegraph through epoxy primer. If it was my car I would finish stripping it and make your fiberglass 'repairs', then prime everything as per normal, inc those stars.

Old lacquer primer & paint ...used to let a lot of things telegraph through. Like even the outline of filler. And those (and other things) generally don't telegraph through epoxy primer, and haven't since it's been around for 30 years. But you could apply a thin coat of glazing putty over them if it made you feel better. But if it were my car I personally wouldn't worry about it. I made many repairs on my car and so far I haven't seen anything telegraph through.

 

I didn't know that the seams wouldn't telegraph through 2K or epoxy primers. I was just going by what DUB used to say about dishing out the seams and filling with VPA to ensure they didn't reappear. Now I have the dilemma of deciding which way to go. Foregoing the VPA repairs would certainly be faster and easier...

 

Just put a skim coat of Evercoat glazing filler over the seams then. Sand most of it down except for a very thin amount. Boom! You're done.