Firewall Repair

1) I really don't have a place to bring my cars to get them sandblasted living northern Vermont, so I do them myself. I rarely have a large enough block of time to do the entire vehicle at once. So the sandlbasting is done in stages. It took me about 8 hours to get the amount of sandblasting done that is that is shown in this picture. By the way, I hate sandblasting. It is a time consuming messy process and I have to travel 45 miles to get it, just because local parts stores are not wanting to carry it anymore.

2) Though not visible in this picture, there were a few small (very small for an E-body) holes in the upper corners of the firewall, where it it meets the upper cowl.

3) I stopped sandblasting at the upper rear crossmember. It is actually quicker to replace the crossmember than to sandblast, prime and fill in the little pits.

4) I like to make sure to sandblast the inner rear quarter window area. Especially on an E-body since the quarter window track is welded in place and it's impossible to get at once the quarter panels are installed.

5) Here's a shot showing how poorly the factory lead work was. Pretty sloppy!

6) The outer rocker panels are supposed to have 4 drain gutters in them. On this car someone had flattened one out.

7) To bring back this detail, I heated the outside up cherry red, inserted a flat head screw driver and kept rotating it until I got the shape and angle I needed. I think it turned out pretty good.

8) I primed all of the surfaces that I sandblasted to prevent them from rusting again. My primer of choice is PPG DP40LF Gray Green for this car since the original factory primer color was similar. I always use PPG epoxy primers on my cars.

9) The first actual repair was the area shown here on the left rear frame rail. I had to cut part of the rear reenforcement off to get to one of the holes.

10) I also had to cut a piece out of the inboard section, just so that I could reach all of the rusted areas.

11) I bought a used left rear frame rail section off e-bay for $100 to fix the tail end of the frame rail. I used a section of it to form a repair section that I butt-welded in place here. Unfortunately I didn't take any pictures of the welding process. This what the repair looked like just before I primed it.

12) The driver's side section of the upper cowl was literally stuffed with paper and bondo to cover up this massive rust hole. I kind of knew this would be a mess when I bought it. This is a typical rust area on Mopars. It probably would have been worse if the car didn't have AC.

13) I was very lucky to discover an original factory inspection mark (orange). I will faithfully reproduce this after the car is painted.

14) There was a rust hole at the main harness firewall connection. I welded in a new piece larger than I needed.

15) I then shaped it to look like the original opening. I also test fit the firewall harness connector to ensure that it would fit after the car was painted.

16) There was a rusted out section where the cowl panel met the firewall. It could only be seen form inside the car, but it still needed to be addressed. In this picture the rust was cut out.

17) Here is an inside picture of the patch being held in place with a magnet.

18) I originally planned to replace the entire upper cowl, but when I got the repo AMD part I found so many discrepencies between the repo part and the original, that I determined it was easier to fix the one I had using the repo part for patches. At least I had the benefit of not moving the VIN stamping.

In this picture a patch is clamped in place. To get things to fit right, I tucked the patch on the inside and cut through both the patch and original cowl as butt-weld. That way the new piece follows the shape of my cut. Otherwise I would have to precisely shape the patch to the opening prior to welding. To learn more on this technique take a look at my 1969 Mustang LE600 project.

19) Here the patch is fully welded and grinded down. Notice the original 3/8" drain hole is still intack. Repo panels don't have this hole. The original factory crease to the left oft he hole is also intack.

20) I was planning on sandblasting the rest of the cowl and firewall later, so I hit my welds with some weldthrough primer.

21) There was a lot of holes and pitting to the right of driver's side winshield wiper, so I cut it out.

22) I made a patch from the repo cowl panel. Again using a piece from the same area to get the contours right. In this picture I had just started the butt-welding process.

23) Here the weld was grinded down. The trick is to not grind off too much of the weld.

24) Here is a picture showing the typical Mopar rust holes that form at the bottom of the windshield pillar.

25) Luckily AMD makes some great repair panels for this area. In this picture I had cut out all of the affected areas.

26) Welding in a new windshield pillar piece is relatively simple. Instead of clamps, I used the upper door hinge bolts and upper fender bracket bolt to hold the repair piece in place.

27) Just like with the previous cowl piece, I cut a patch off from the repo cowl panel and butt-welded it in place.

Cowl repair work halted at this point so that I could get the floors put in. I needed to get the big jobs out of the way before snow began to fly. Once it gets cold, sandblasting outside becomes very difficult. The lines get clogged up with frost (warm indoor air moving through a small orifice outside causes the moisture in the air to condense and freeze the lines).

107) A popular area to find rust holes is at the bottom of the A-Pillars (aka Door hinge pillars). There were two small holes on this one. In this picture I had already cut the offending rust out and prep-ed the areas for patches.

108) In this picture the top hole was repaired and I was ready to fix the second hole. It should be noted that all patches that I installed were made from new scrap metal taken from the repo quarter panels and the patches were always butt-welded in.

109) Another popular place for rust is rocker endcaps. In this picture the rust was cut away and the area was prep-ed for the new patch.

110) Here it is with the patch welded in after the weld was ground smooth.

111) The left side was much worse on this car, so I thought I would go into more detail with this side.

112) The first thing I did was to cut away all of the rust.

113) Then I sandblasted and ground away the residual surface rust on the metal I wanted to keep. It looks pretty intimidating at this point.

114) In this case I started by repairing the rocker endcap first. Notice that the patch is larger than what is required? That is because it is easier to weld up beyond the end of the original metal and grind the patch back to the correct dimension, than it is to stop a weld at the exact edge you need.

115) Here it is after the butt-welding process and a little bit of grinding. I use 36 grit disks on my air grinder to get the welds flat as possible. If you do it right, you will not need to use any filler.

116) Next came the side panel bottom. The patch needed to have a couple bends in it to match the original contour lines, which you can see marked on the patch (but not bent yet).

117) The bends I made in a bench vise. Here it is welded in.

118) Here is the last patch. Again the patch needed to have a bend in it to match an original contour line.

119) Here it is all welded up. You may notice the front part of the A-pillar where it meets the rocker. There was a small rust hole that opened up to a larger one after sandblasting. I was able to just plug weld the hole instead of having to patch it.

120) In this last picture I hit everything with some weld-though primer to temporarily protect my work from rusting and to get a good visual of my work. The lines in the patches came out pretty good, don't you think?