Sunday, November 20, 2011

driver's side floor repair--If at first you don't succeed...

After a couple of weeks of "challenges" on the home and work front, I got some time to get back working on the fastback.  And since it had been awhile since I did the fit of the front floor, the holes for the plug welds and edges needed to be cleaned up again to get rid of any surface rust that may have started to form.  So I pulled the floor out and got it all shiny in the right places...

Then I moved on to clean up the edges of the floor, the firewall extension, and the frame rail surfaces.  I also got underneath and cleaned up the edges of the transmission tunnel and driver's side passenger floor pan....

Then I put the floor in and got ready to use my nifty Eastwood weld clamps to keep the floor in place.  I used these on the right front splash apron and they worked slick...

If you are going to do any butt welding of auto body panels, these are definitely worth the price of admission.  I put the floor in and started the clamping process at the seam where the back of the driver's floor met the front edge of the passenger floor.  Things looked pretty good....

The gap was near perfect and proceeded to install clamps moving toward the transmission tunnel, but the gap at the corner was not closing up.  The bend in the floor pan was not tight enough. 

So I undid the clamps and got out my trusty hammer and dolly and proceeded to get the radius tighter.  It took a few tries and clamping and unclamping and more hammer and dolly work before the floor pan was getting to where it needed to be.

I still wasn't happy with the fit.  After looking more closely at the joint along the transmission tunnel, I discovered the floor pan needed to have some more material removed and some more hammer and dolly work to match the contour.   It was starting to look good....

I started to put the rest of the clamps in.  But as I got closer to the front of the transmission tunnel near the crossmember, I noticed the gap was widening.  I could pull it closer, but then the floor wasn't flush against the transmission crossmember  or frame rails.

Not good.   I made sure the floor was flush to the frame rails and crossmember and started the clamping process all over again for the umteenth time.  It was at this point that I realized there was no way I could keep the floor flush and get the fit at the transmission tunnel without the lip at the inside of the rocker panel having a 1/8 inch gap.  I did some measuring and there is way too much gap to even attempt to weld the joint together...

This is the joint in the middle of the floor and transmission tunnel.  It's about an 1/8" of an inch which is twice the width it should have been.  Here's the joint at the back of the driver's floor pan to passenger floor pan joint.

It's a little wide at 3/32 of an inch.  Ideal is 1/16".   The gap that was tight here spread as I tried to massage the floor and transmission tunnel gaps.  This just isn't going to work.

So...after all the hours of work on this one panel, it looks like I'll be ordering another floor pan and starting all over again.  The only think I can think of that screwed this us is that when I was trimming the floor, I didn't get it flush with the frame rails and transmission crossmember.

Oh well...   If at first you don't succeed, try, try again.


  1. Don't give up so easily. All I did when I had a gap that was a little too wide was to insert a strip of sheet metal edgewise into the gap and tack it in, weld the cap (over the strip that acts as a filler) and then cut/grind away the excess strip on the other side of the joint with the angle grinder. Sometimes, when the gap was really big, I just cut a patch strip the same dimensions as the gap and tack and/or welded it in. After grinding, you can't even tell that there was an issue.

  2. Further... Butt-welding is notoriously difficult. Even the pros have some difficulty getting gaps perfect, especially over such a large, uneven area like a floor. The best we can do is get close (which it looks like you did a really good job at so far) and work around the flaws. Seriously, nobody will be able to tell the difference between weld metal, original metal, and patch metal after the grinder is done. Metal is metal!

  3. I agree Alex - I don't think it looks too bad Dennis. Maybe sleep on it and give it a go over Turkey Weekend?


  4. One more suggestion - as Alex said, butt welding is a real struggle, even WITH the correct sized gaps, in fact I gave up on the idea completely when I was repairing my passenger fender apron. However, one other thing you can use to fill the gap is a welding rod - this worked for Tom Mackie when he was repairing a sunroof; see this link:

    Also...frustrations like this are all part of the restoration/learning process, so don't be disheartened.

  5. Holy cow! Thanks for the Tom Mackie link. That's exactly what I need to do and he got the welding wire to work with the clamps. Excellent!!!!

  6. Butt-welding is a real pain and worse when it gets too hot and warps. Take you time, and metal filler is a ton better than the plastic filler I found on my project.

  7. James, I got a can of Everlast Metal-to-Metal, based on your and Sven's experience. I did an 18 gauge roof insert on my 1929 Model A tudor hotrod where I learned how to spot the panel in and then move around to keep if from warping. However, that joint wasn't a butt joint but a 1/4" overlap. Much easier. Not sure how much I'll get done with family coming to town for Thanksgiving. I'll keep everyone posted on the progress.