My Beetle Restoration

Now that I have the repair pieces made to replace the tunnel rails, it's time to start cutting and welding them in. My plan is to replace the rail from the point that I removed the tunnel bottom plate, all the way to the end in the frame head. I made the pieces long enough on the tunnel side of the pieces to reach past most all of the rust damage. I will have to patch a couple of places where the damage extends upward past them, but these will cover almost all of the damage. I will weld these pieces in on both sides and ground them down on the outside, but leave the welds as is on the inside for strength. They will not be visible and I'm mainly interested in them being strong. I'm starting on the passenger side as it has the least amount of damage and is the least complicated.

The first section took quite a while to do as I tried different things to figure out the best way to do this. I first laid out a replacement piece on top of the rail, marked the length, and cut 1/2 inch or so through the lip down into the tunnel. After that I cut across between those two cuts to remove the lip. I then placed the piece on the tunnel, lined it up with the existing lip on both ends of the cut-out, and clamped it in place. With it clamped, I then used the piece as a guide to cut through the tunnel. I now had a cut-out just a little larger than the size of the piece. I first held the piece in place for welding using panel clamps, but after just a few tacks across the joint, the panel clamps were locked in tight from the shrinkage of the metal when cooling and I could barely get them out. From that point on, I just used vise grip style clamps. The first three sections were pretty much the same and just involved determining and making the cuts and clamping and welding the pieces in.

The fourth section on this side connects to a tube support bracket for the clutch tube, fuel line, and choke tube. I drilled a couple of spot weld holes in the piece to attach it to the support brace. Next, I will replace the same four sections on the driver side.

Now on to the driver side of the tunnel to replace the tunnel rail. This side is definitely the worst of the two sides. During the two decades that this car sat outside in the elements, water apparently pooled in the floor pans and there must have been water in higher volume and for a longer period of time on the driver side due to the damage. The tunnel on this side was rusted completely through to the inside in one area and this damage will be cut out on the first and second sections being replaced. In the first section, the cut-out for the piece did not extend high enough to include all of the damage, so I had to make two small patches. I welded them in first and ground down and dressed the welds. I then welded in the first section on both sides and ground down and dressed the welds on the outside.

Next I replaced the second and third sections. The third section had a little area that had a little pitting. Rather that patch it, I ground the area down to clean metal and filled it in with weld. I then welded the section in as usual.

The fourth section includes metal that goes in front of the pedal cluster support plate. Part of that support plate was severely rust damaged, so I first cut out for the tunnel rail replacement piece and then cut it out and welded in a replacement piece on the support plate. I had to grind out an area on that new piece to allow for the pedal cluster mount to fit into the tunnel. I checked it with the already powder coated cluster mount and taped it with tape to protect it from scratches. Once satisfied with the clearance, I welded on the new piece. I used a copper bar behind it as I welded it to keep the weld from blowing out on the edges. I ground down the welds on the outside of the support plate and left the ones on the inside. I drilled holes in the tunnel rail replacement piece to weld to the support plate and then welded the fourth section in. I left the area covering the hole for the pedal cluster mount for now.

With the fourth section welded in and the welds ground down and dressed on the outside, I now had four feet of tunnel rail replaced on both sides. Next up is to continue and finish the tunnel rail replacement through the frame head and up to the frame head front plate.