GTO Body work Part 1

This page deals with the bodywork performed on a 1967 GTO convertible. Part 1 deals with the rear sheet metal work. 


Like many thousands of other GM cars from the 60's, this GTO has developed some rust over the years. It's first "refurbishment" was done in the late 70's by the previous owner. Some of the work was very nicely done, but some was not so nice.

1967 GTO tailpanel creeping rust

The tailpanel replacement was done well, but the driver side quarter panel was crudely repaired with some bent up sheet metal grafted on with a huge lap weld. The body accent contour behind the rear wheel was way off and the wheel well trim did not fit well. Inside the trunk you could see a huge ugly joint with a sharp sheet metal edge. But still, when I bought it in '87, the car looked pretty good and the paint was in good shape. 

In the first decade or so of my ownership, the car had to stay outside. The trunk rusted from the inside out from all the years of a leaky top. Fixing the trunk was the first job I tackled. This work is highlighted elsewhere on this site on the trunk page.

Starting with the trunk work first gave me valuable experience with metal work. I was able to learn how to cut out old metal with minimal collateral damage, form metal patches, set proper gaps for butt welds, and perfect my butt-welding stitching technique.

While doing the trunk repair, I also removed all the damaged quarter panel sections. This made it much easier to do the trunk work. Now that the trunk is done, I'm starting in on the exterior metal repair. 

Tail panel

The tail panel has suffered from rust probably like the first one did. In particular, some of the edges of the light cutouts have gotten very thin and pin-holey. This damage seems typical from the way the tail-light design collects moisture between the seals

Rusty GTO tailpanel near light cutouts

I cut out the damaged lip and made a long "L" piece of metal to replace it. Here it is tacked in.

Tail light panel patch tacked into place on 1967 GTO

Here's the opening to the right with some slightly different shapes. This piece hasn't been tacked yet and it held on with some magnets.

Another shot of GTO tail panel repair

Rear Quarter End

Next up was the "vestigial" tail fin of the driver side quarter. For whatever reason, the driver side rusted out. The passenger side is rust free. The previous repair involved pressing in the swiss cheese and filling it with body filler. Well, while that method happened to work well for over 20 years, I just had to grind away the filler and put in some good metal.

Rusty end of 67 GTO quarter panel.

Below, the quarter panel rot was cut out. Also note the small patch I made to fix a small area on the tail panel. There were a few pinholes here, so I cut this out too and the patch is ready to be welded in. Note too the finished tail light opening in the lower right.

Quarter end face on 67 GTO cut out. New tail panel patch also ready for welding.

This quarter area has a complex set of curves and was tricky to make. I tired to hammer out a single piece with all the folds, but it couldn't be done. So I made a few slices, bent it all to shape, and then welded up the slices. I was very happy with the final piece.

End face GTO quarter panel patch before

Here's the final piece massaged into shape and the slices welded up.

End face GTO quarter panel patch complete and ready to go.

Here's the piece held into place with some magnets to test fit. I was pretty careful about checking fit-up so I made sure to install the trunk lid and check all clearances as well as the trim fit. The extra holes are for plug welding to the tail panel piece underneath. Two holes are all the way through and will remain for the hockey stick trim clips.

End face GTO quarter panel patch ready to be welded in,

And finally here's the patch fully welded and ground down. There are some subtle bumps and ripples, but these will be addressed with a skim of filler. Click for a bigger picture.

Rear patch welded onto 67 GTO quarter panel

Convertible Gutter

Now moving on to the convertible "gutter". This small area was rusted out when I bought the car. I didn't notice it when I bought the car because this area is normally hidden by the top well cover. This rust was also odd in that the driver side rusted out, but the passenger side is completely solid. Here it is with a donor gutter section from an A-body Oldsmobile.

Replacing convertible gutter rust damage 1967 GTO

This area is where two pieces shaped like a "gutter" overlap and were spot welded together and covered with seam sealer. Underneath there is a very thick gauge piece on the left. Thankfully all that is in perfect shape. So I only ended up cutting out the "U" shape gutter part.

Gutter rust cut out of 1967 convertible GTO

I carefully cut away at the donor piece until it fit nicely into the void. The donor part itself needs sandblasting to get the old paint and residue seam sealer off. So welding this in will have to wait until sandblasting-friendly warmer weather comes.

Patch fitted into place GTO gutter

March 2010

Work was stopped for some home repair, but that's done. The weather has cooperated, and I managed to sandblast the gutter and weld it in. Ahhh, nice. Still need to weld the two holes in the bottom of the gutter on the left to simulate spot welds. 

Welded gutter section

Quarter window ledge reveals

The sections of the quarter panel underneath the stainless quarter reveal trim by the quarter windows is rotted. On convertibles, there is a "L" shape welded underneath for strength but moisture collects between the sandwich and rusts. The repair from long ago involved  fiberglass and again, the job was good, but I cut it out to repair with metal. 

Starting to cut it off:

1967 GTO quarter window reveal rusty metal removal

Here's the start of the patch, an "L" shape, but it's still got no "swoop":

Beginning to shape GTO quarter window reveal patch

Instead of mangling the metal to put in the swoop at the forward end, I decided to use the same tactic used earlier, the slice and weld technique. I made some slices and bent the swoop into the patch. The slices then had a nice gap on the ends, but toward the top they closed to a point. I used my snips to cut the gap all the way to the top for a good weld.

GTO quarter reveal patch sliced to form a curve.

Next to weld up the slices:

Welded quarter reveal patch

Next up grind the welds down and smooth 'em:

Ground and smoothed GTO metal patch

April 25, 2010

April has been the most productive month ever spent on the GTO. I got alot of metal work done. But first, here's the completion of the quarter window reveals that were started in March:

The driver side piece shown above was trimmed and the outer side was bent up to fit. I also added the inside "L" shape strengthening piece. Here is it ready to be welded up.

Driver side quarter reveal internal brace fabrication

Here it's shown held on with magnets for a test fit.

GTO quarter panel reveal patch test fit into place

Shown next is the passenger side which was a bit bigger. It's welded in but not ground down yet. 

Passenger side GTO quarter reveal patch welded in

Rear Quarter Wheel Openings

June 5, 2010

With the quarter reveals done, it was time to move onto the quarter panel wheel openings.  During the body survey I did 6 years ago, I thought that the wheel lips on both sides of the car were in good shape and salvagable. But after poking here and there, and sandblasting here and there, I found that things were actually worse than I thought. The worst side is the driver side with pin-holes pretty much all along the edge.

The dreaded pinholes in the wheel lip of the GTO

Thankfully, the pits and holes don't get near the top part of the flare.

The front edge of the opening was pretty damaged however. This area was covered with a skim of filler from the 70's resto.

ravaged driver side front section of rear quarter panel opening. Whew.

When I first started all this work in 2004, suppliers said that complete quarter panels were only months from being released, but 6 years later no quarter panels. So, since forming sheet metal is kinda fun after all, I fired up my jigsaw, made some wood forms and fabbed up some patches myself.

For the most part, the cheesy areas and pinholes confined themselves to very small regions, so patches small and managable. But still, it turns out the complete drivers wheel lip had to be replaced. I started at the front.

First, I made a cardboard template, then formed a 2 dimensional wood form to follow the front wheel opening. I cut out a piece of flat sheet metal to the approximate size shown with the purple marker above, then put it onto my 2D form and beat over a lip about 1/4 inch. I snipped a small "V" into the lip where the accent was to go, then bent the accent. With such a small lip, I could then form the concave curve below the accent and the convex curve above.

Driver side patch with accent bent in.

The next thing was to snug it onto the surface of the quarter panel and then fab up the rest of the inside lip flange. Here's the passenger side shown being done. (Both sides needed the same work)

Fabricating the GTO inside wheel lip, starting with the cardboard template

The steel was cut out and clamped into place so it could be tacked onto the main patch.

GTO inside wheel lip ready to be tacked to the patch
Passenger side leading edge of rear quarter panel patch

The piece was then finished welded and ground down. Here's the driver side being fit.

Test fit quarter patch for GTO

Rear quarter panel patches

Since the driver side quarter panel lip would have to be cut out, there was danger the quarter would get too floppy from being separated from the inside wheel well flange. So I decided to finally install the large rear patch panel to tie the quarter to the wheel well opening in the back. 

The large panel was sheet-metal-screwed to the quarter with about a 3/4 inch overlap. I then began slicing through the sheet metal sandwich at the wheel opening joint. This was tacked at the front and then I proceeded to slice and tack toward the back in about 6" increments. I peeled away the waste metal as I went. I cut off a few inches of the patch at the top as I didn't need to go up that high for repair. These rear patches are pretty accurate, although the wheel lip edge is a little "soft" compared to the sharper original edge.

Rear quarter panel patch ready to be installed on 1967 GTO
Panel attached with screws and tacked on the front.

This next shot below is of the passenger side. Same deal here too...I started at the front and cut through the patch and original metal with my 4" grinder with 0.040" cutoff blade. Then made sure the panels to be joined were flush with each other and tacked it.

Passenger side quarter panel patch being butt welded to original quarter metalSlicing and tacking towards the back on 67 GTO quarter panel patchView of the inside of the butt welded panel
Another view of the butt welding technique on 1967 GTO rear quarter panel

The panel is now completely tacked in, although I still need to weld the bottom edge. Also note that the rear of the panel over the bumper cutout has been smoothed with a hammer and dolly. This area was very wrinkled so I spent a while slowly teaching myself how to use these tools. I'm very pleased how it came out. It will require much less filler than before. 

67 GTO rear patch panel is completely tacked in

Driver side wheel lip

As mentioned before, the wheel lips ended up having pinholes which weren't noticed until sandblasting revealed them. The pinholes were sprinkled all over the driver side arch, but thankfully the holes were found in the flat area below the accent flare. This allowed a repair without needing Italian maestro coach maker metal skills. 

First, I cut out the bad metal with various tools, mostly the angle grinder with cutoff wheel. I didn't drill out any spot welds; I just cut the sheet metal between them, then chiseled and twisted the old metal off.

Cutting out the damaged wheel lip metal on 67 GTO

The inner wheel well was remarkably in good shape, except for the front edge. So I cut it off as shown.

Inner wheel well lip damage removed on 67 Pontiac GTO

I made a piece and replaced it.

Inner wheel well lip patch for 1967 GTO rear quarter

Here's the inner wheel well coated with Masterseries paint. This pic also shows how much edge I ended up replacing. There is a 6" section of the arch on the forward end that stayed, but even that needed the inside flange cut off where it is joined to the wheel well.

Ready for patching quarter panel

So I made more templates to trace the wheel opening shape, then made some more wood forms. I made two pieces with the same curve so the metal could be sandwiched between the wood. The lip is then easy to hammer over the edge of the wood when the "sandwich" is clamped in a vise.

Wood form with sheet metal patch ready to be formed on 67 GTO wheel lip repair

The metal was put in between the wood forms, and the lip folded over to one side:

Forming the edge of the new wheel lip
The wheel lip face for 67 GTO

The piece was then fit to the car and the very slight curve on the ends toward the center of the car were put in by hand. I then fabbed up the large flange that gets welded to the inner wheel well flange.

Wheel lip and flange ready to be welded together for 67 GTO rear quarter.

The two were then stuck onto the car and tacked together, removed, finish welded, ground down, and then coated with the masterseries primer.

Outer lip being attached to lip flange

The newly tacked patch pieces were removed and fully welded, ground down and primed. The side of the patch was intentionally oversized and now ready for trimming to fit the missing metal. Nothing special about this; just careful trimming and checking until it fit nicely.

Before installation, large holes were drilled on the flange for plug welds to the wheel well flange. Here it is tacked onto the car.

1967 GTO wheel lip patch tacked into place

I thought I could save a section of the lip between the large patch and the rear quarter panel patch, but it didn't cut the mustard. So I made a small patch to fill this void.

Test fitting unexpected wheel lip repair patch for 67 GTO
Patch test fit with magnets

Here's what I ultimately had to remove on the passenger side wheel lip (in green marker also)

Metal removed on 67 GTO quarter panel wheel lip and primed

And in a case of OCD, I fixed the odd little feature that is hidden behind the bumper when installed. I would guess this tang was here for the factory to use when putting the car together. It was damaged at sometime in its life, so I repaired it.

Overzealous application of patching on GTO quarter panel
Body alignment tang on 67 GTO quarter panel.

Once all the bits were tacked on, it was all stitch welded together. The welds were ground down and the wheel well trim was fit, and it fits like a glove....ahhhhhhhh.

67 Pontiac GTO rear wheel well trim fit passenger side

As seen below, the trim sticks out a bit near the rocker. This was how the original quarter was as built in Baltimore in '67; the quarter hangs over the rocker slightly, so the trim sticks out a bit too. I duplicated it when patching because if I didn't, the patch would not have matched the lower part of the quarter as it goes toward the door. These cars were built somewhat sloppy.

GTO rear wheel well trim leading edge passenger side

Trunk Lid Repair

June 30, 2010

The 1967 GTO trunk lids are infamous for rusting at the corners. No wonder, since there isn't any paint or coatings on the insides where the skin and brace metal are sandwiched together. To tackle this problem, I went to the extreme of cutting the lid up.

GTO trunk brace removed for repair
67 GTO trunk lid taken apart

First I peeled the skin open at the back side edges. I then cut along the flat area that the trunk weatherstrip bears against. This would allow easier smoothing when welded back on. 

When I removed the brace section, I noticed among the heavy rust pits there was still some bright bare steel showing. Geez if GM had just put some kind of coating on these areas....

I sandblasted everything and cut out the thin areas. Patches were fabbed and welded into place.

1967 GTO trunk lid repair driver side
1967 GTO trunk lid repair passenger side

Everything was coated with the primer and I put the brace back on in preparation for welding it up. The skin was bent back down when the brace was welded in, but it cracked along the edges. I simply welded that up and ground it down. In the picture below, near the bottom, that's a new flap welded on ready to be folded over the brace. 

67 Pontiac GTO decklid brace ready to be welded back on

Here it is all welded and ground down. Some more smoothing will be done and then some fine filler work and finishing.

Deck lid welded back together on 1967 Pontiac GTO

To see more, please go to the next page: GTO Body Work Page 2

Or, go back to Home Page



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