69 Firebird
77 Trans Am
54 Pickup
52 Chieftain
Other Projects
About Me
Restoration: Metalwork
  • 70% of floorpans replaced due to leaking T-Tops
  • Firewall welded and smoothed
  • Upper cowl welded and smoothed
  • Rust areas repaired on tail panel behind bumper supports
"Oh, t-tops how I love thee; let me count the ways. Thou make the 2nd gen f-bodies rot from the inside out when thy seals fail and leak water all over the floors."

Floor Pans

I knew the floors needed work, but not as much as I ended up finding. Oh well, more time with the welder!

"CSI: F-Body"
Pictured here are the remains of what used to be a stock floor pan. Sadly, this floor pan lost it's battle with water. R.I.P.
LH Front Floor Pan - Original
The front floor pans on the driver's side were not terrible; nothing was rusted through, just a lot of pitting. But, the lower portion of the toe boards needed to be replaced, so I went ahead and did both areas since I had to get in there with the angle grinder anyway.
LH Front Floor Pan - Removed
After removing all the rusted area, I prepped the surrounding area by wirebrushing it down to bare metal and cleaning everything.
LH Front Floor Pan - Complete
I used the old floorpan to cut out the floor pan patch panel from the re-pop full-length floorpan. I added 3/8" for a small overlap. Then, I welded that into place. Next, I used flat 20 guage steel sheet to bend and form a new custom toeboard. I made the toeboard in three sections, since bending a single piece of steel to the toeboard countours would have been difficult. Bending 3 small sections and welding them back together is much easier.
RH Front Floor Pan - Original
This is the original front floor board from the passenger side. There were numerous small holes of rust in the floorpan and some bigger holes in the toeboard.
RH Front Floor Pan - Removed
After the old pans were removed, and it was cleaned and preped for the new metal.
RH Front Floor Pan - Patch
Here is the patch panel I cut from the re-pop pan, with an extra 3/8" on the edges to help place the panel correctly. If you leave yourself a little overlap on the floorpans, the metal will try to "sit" in it's proper location by centering itself on any pre-moulded creases and contours between the original pan and the replacement pan. Since it's only a floorpan, you don't care about the little overlap. You are going to cover the area with seam sealer on both side when you are done anyways.
RH Front Floor Pan - Patch
This is the simple toeboard I made from flat 20 gauge steel that I bent at an angle. The passenger side toeboard had no complex bends.
RH Front Floor Pan - Complete
Voilá, the final passenger front floor pan after welding.
LH Rear Floor Pan - Original
Yep, that pan needs to be replaced too. The previous owner before my friend "patched" the rear floors by pouring fiberglass right over what you see here. Literally, right over the rust, with no extra treatment. Hooray for doing a half-ass job!!
LH Rear Floor Pan - Removed
Then the old floor pan was removed and the area was prepped for the new pan.
LH Rear Floor Pan - Patch
Notice the holes I drilled in the panel where I would eventually plug weld to the underlying metal to mimic the factory spot welds.
LH Rear Floor Pan - Complete
Another floor pan completed and one step closer to the goal. On a side note, if you plan on welding when it's hot out; you will sweat, and it will come through your welding gloves, and it will flash-rust your patch panel. :)
RH Rear Floor Pan - Original
Another rusted pan, another cheer for t-tops, and another job to do.
RH Rear Floor Pan - Removed
A little trick when removing the rear floors from a 2nd gen f-body. Go underneath the car with a small drill bit, and drill holes up throught the floor just outside the seat frame support. Then, go back inside the car, and connect the dots. This will tell you where you cannot cut when you take out the pans. So then when you cut the pans out from the top, you cut to the line, then stop, and use an air chisel to take out the spot welds on the seat support.
RH Rear Floor Pan - Patch
I took the rust panel that I cut out and laid it on a re-pop floorpan that I bought. I traced the area, then cut out the area 3/8" wider to create a small overlap. Then I drilled holes in the patch panel to plug weld back to the seat support and rocker panel area.
RH Rear Floor Pan - Complete
Here is the replacement pan after it was welded into place.
LH Under Rear Seat Pan - Original
I guess the t-tops let water leak onto the rear seats, which then went down under the seat, and rotted out the pans under the rear seats. The driver's side under rear seat pan was by far the worst area of floor damage in the car
LH Under Rear Seat Pan - Original
The rust even came up off the floorpan and up into the seat belt support area. That had to be removed.
LH Under Rear Seat Pan - Removed
The rear under seat pans were by far the worst to remove since there is a lot of bracing under the floorpans. You've got a frame rail, two seat belt retainer plates, the complete rear leaf sring pocket bracing, and the rocker panel all to contend with. Thankfully, even with all the rust above, none of the underlying structural steel was really damaged. A quick treatment of Ospho and we were ready to go.
LH Under Rear Seat Pan - Patch
Since nobody makes re-pop pans for under the rear seat floor pans, I had to find a donor vehicle. I came across a donor '79 T/A that my friend removed the suspension for a 50's Chevy truck, and he said I could cut on it for FREE. Two hours with the Sawzall netted me two complete pans with all bracing attached. As you can see, even the donor pans needed work. Oh well, they are better than what I had.
LH Under Rear Seat Pan - Patch
The donor metal still had the frame rails, spring pockets, and bracing attached. So I spent 2 hours drilling out the original factory spot welds to separate the pan from all the bracing, and then I spent the next 2 hours making repairs to my new patch panel where it had rust damage. The finished donor pan turned out pretty good.
LH Under Rear Seat Pan - Complete
This was the hardest pan to weld back into place. I'm sure I got the donor pantoo hot and introduced a little bit of panel warp into the donor metal when I repaired the patches on the workbench. No big deal. Nothing I couldn't fix with a little brute force against the donor pan to push it into place as I welded it.
LH Under Rear Seat Pan - Complete
Evidently the outer rear seat belt bolt changed location from '77 to '79. The bolt hole where you see it here is the original position for the '77. The big welded hole just below it is where the bolt was in the '79 donor pan. The strangest part was that the '77 seat belt brace had holes for both positions. Look at the picture before, you can see the hole in the bracket with nothing in it. Maybe there were known design changes coming up later on in the model years...
RH Under Rear Seat Pan - Original
A lot of pitting and a couple of places where it rusted through, especially near the seat bracket.
RH Under Rear Seat Pan - Removed
Cleaned, prepped, and ready for the donor pan.
RH Under Rear Seat Pan - Patch
The passenger donor pan was in fairly good condition. No extra metal work required, just the hour or two to remove all the spot welds to take it off of all the bracing/frame.
RH Under Rear Seat Pan - Complete
Here is the new donor floorpan in place. I had to re-create the hump between the rear floorpan and the under rear seat pan with a piece of flat steel. I bent it up to match the contour of the underlying brace, and welded it into place. Looks good.
LH Trans Tunnel - Original
What a strange place for rust; around the seat bolt brace on the trans tunnel... Maybe the t-tops leaked directly onto the seat belt...
LH Trans Tunnel - Complete
I cut out the affected area, then drilled out the spot welds that hold the heavy duty seat bolt bracket into place, made a new piece of 20 ga steel, and welded the heavy seat bolt brace back onto it. Then I welded the 20 ga piece to the the outside of the tunnel to give more overlap for stength if there ever was a collission.
Now all I have to do it grind all the welds down and paint the floors.
Here is the original firewall before I made any modifications to it. The previous owner tried to grind a hole in the firewall to shove the 4 speed clutch linkage through, but it ended up looking kind of frankenstein, so I know that needed fixing. Since I decided to convert the car to Vintage Air, I also wanted to close up all the unnecessary holes in the firewall. Basically clean it up a bit.
After I finished with my modifications, this is what the firewall looked like. From left to right: Welded up the old blower motor hole, closed up the holes that mount the old evaporator box to the firewall, welded in the large A/C evaporator box hole with a block-off plate from Vintage Air, closed up the original A/C wiring harness holes, and finally, fixed the 4 speed clutch linkage hole next to the steering column.
I've never liked the way GM designed the transition between the firewall and the cowl on the 2nd gen F-Body cars. The two pieces of steel had multiple bends and then the transition was filled with seal sealer from the factory. It left a very unfinished feeling to the engine bay and it looked cheap. So, I folded the upper lip back on itself with a hammer and dolly, and then I welded that folded metal back to the cowl to create a smoother transition between the cowl and the firewall.
I had rust on the rear tail panel when I took off the rear bumper. Water got behind the bumper brackets, stayed there, and rusted out the tail panel. Nothing a little time with an angle grinder and a welder couldn't fix.
Notice in these two pictures that the rear tail panel also had some damage done to it. There were 20 or so holes in the lower tail panel where it was pulled out with a slide hammer. I guess someone got rear ended in the car sometime in the past. Oh well. Since the lower part of the tail panel is covered up by the bumper, I decided to just weld up the holes, grind, and paint the tail panel.