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June 2, 2020

A & B Posts, Sills, Inner Wings

With the right side floor finished, I had a good foundation for the inner sill, but the A and B posts really needed to be repaired first, so I pulled the car outside, and blasted those areas.  In GT6-speak, the "A post" is really everything in front of the door.  The lower three of four inches of my A post was essentially missing.  The new floor flange at least showed what had to be done.




A little piece of the floor had to be patched, and the flange fixed.




There is actually quite a bit of shape in the piece of the A post that I needed to replace--several angles, and a sort of half-round channel feature.  I briefly considered trying to make it all in one piece, but finally wimped out and decided to make patches with one feature each.  A man has to know his limitations.

The pieces with the angled bends weren't too challenging, but the half-round feature had me spooked.  The fact that it ends in mid-panel freaked me a little.  I have a bead roller, but it has no rollers that matched the contour, and no good way to do a nice end shape.

Enter the 3D printer to the rescue.  I printed a simple tool and die that did the job.  Certainly not production tooling, but for one or two pieces, it worked great.




The rest was easy by comparison.




Then, another common rust area on these cars is this seam midway up the A post.




Moving to the B post, I was having a hard time seeing exactly what the construction and the damage was.  Considering all the rust on the wing, I decided to remove it.  That revealed a lot of rust damage that would be hard to see, let alone fix otherwise.




Tabling the B post repair for the time being, I started rust repair at the rear.  Blasting the area really gave a much clearer picture of the damage.




A plan emerged.




The boot floor first had to be patched under the stiffener for the bumper brackets.




Finally applied inner wing the patch.  Almost forgot the stiffener underneath the boot floor.




This brought me to the really scary part:  the wheel arch.  It was pretty much all curves.  Compound curves.  There were two rusted areas: one on the trailing edge of the arch, all the way to the top, and a smaller area on the leading edge.  The rear one was up first.




Not confident that I was good enough to do it in one piece, I did it in two. The first one was the easy one.




With maybe 50 trips between the car and my Harbor Freight shrinker-stretcher, I had something that seemed to fit OK.  The numbers on the arch are measurements of the thickness of the face of the arch, taken from the remnants of the original metal.




Then to the front of the arch.




Before the lower part of the arch front, a little patch on the cross member, and one on the front face of the arch.  The body is upside down in these pics.




Then a curly pieces.

 


So, now finally back to the B post where this all started.  I cut back the original metal beyond all the holes left from removing spot welds., and also replaced that swiss-cheese flange.




Then cut a new piece to fit.  The original panel had a largish hole that was "dimpled" around its perimeter.  A simple little die and a large washer made a nice reproduction dimple.




Here it is in place.




All of this was in preparation for the inner sill.




The inner sill itself was in OK shape except for the bottom inch and the bottom flange.  These are available as reproductions, but I thought I could repair the one I had.  At least I knew it would fit.




There were a pair of elongated holes in the inner sill.  I wouldn't realize what they were for until later, but the bottom portion of both of them was gone.  The holes were dimpled, but sadly, a different size from the dimple die I had already made.

I made a new dimple tool, and made a flared hole to match the ones in the sill.  I only needed half the hole.




Similar for the other end.




Then cut off the bad part and replaced it with good metal. 




Replaced the end flange.  There wasn't much left of it after removing the spot welds.




Test fit went OK.  I could use the old spot weld holes for alignment.




I went to great lengths to keep the bottom flange straight while welding the seam.  The minor warpage I had was fixed by the shrinker/stretcher.  I welded the sill from the inside to keep the outside looking better.  I only did minor grinding on the inside.




Between the inner and outer sills is a "strengthener" piece.  Mine was mostly toast, but making one is pretty simple.  Forensic examination of the remains suggested the size and shape, and the location of holes.  Online pics helped, too.




Since the space between the inner sill and strengthener would be inaccessible after put together, it made sense to coat them before assembly.  Two coats of a good epoxy primer should hopefully be adequate.  The flanges got a couple of coats of weld-through primer instead.




Mounting surfaces on the body were prepped with weld-through primer, and the inner sill was positioned and spot welded.




Then inserted the strengthener.  This is when I realized what those big slots were for in the inner sill.  They are for spot welder access for the ends of the strengthener.




At this point, I thought it prudent to get this side of the car under some kind of rust protectant in anticipation of our wonderful Midwest summer humidity.  A coat or two of a 2-part epoxy primer.
 



Not much doubt about where to go next.




The only thing I didn't finish on this side of the car is this rust damage to the bump stop and wheel well.  Both sides are similar, and I think I'll wait until both sides are done to do those areas.




This has been a pretty involved job, taking over a month so far, including the floor repair.  Hopefully, the other side will be quicker now that I know what to expect, and have some of the tools made.  Cost was just some consumables.


UPDATE

June 28, 2020

Today, I finished the drivers' side floor, sills, posts, and crossmembers.  Starting point was similar to the passenger side...




...but the front section of the floor was a little worse.  It might have been easier to just fabricate a front pan and install it wholesale.  I call this the Frankenfloor.




The new drop flange on the floor.




On this side of the car, there was some accident damage on the rear corner, which was repaired (by me) over 30 years ago.  Part of that repair required cutting out a section of the inner wing.




That got fixed, along with the lower edge of the inner wing, and the rear of the wheel arch.




A and B post rust repairs were similar to the other side.




The inner sill and strengthener panel were in worse shape than the other side.




I made a new strengthener, but wimped out and just bought an inner sill.




I always cringe when I'm forced to buy panels, since the fit is so often not great.  With it's rear end fitting snugly, the inner sill had a 1/2 inch gap at the front, but with a little encouragement, it finally fit better.




A number of the welded nuts on the bottom of the floor pan had to be replaced.




The last item up for the floors/sills was the floor cross members.  They stiffen the floor and attach it firmly to the frame.  Mine were largely missing the flanges that attach to the floors.




A few patches here and there fixed that right up.




Test fit them, applied a few tweaks, and finally plug welded them in place...

 


...which of course messed up my fresh primer underneath.




But a little more primer, and we're good again.


 

This marks the end of the floor/sill/post parts of the body.  On to the rear wheel wells.

Comments to Ed at elhollin1@yahoo.com

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