Ongoing rust repair on my '75

[Neb]

Just wanted to show some of the work I've been doing on my Z to fix some thoroughly rusted floorpans and rockers.  It is still very much in-progress but I'll try to update as it goes on.  Hopefully it'll be of help to someone as a reference, or at least encourage folks to give it a shot.  If you see anything wrong with the approach, please let me know! 

Some quick background: The car is a '75 that I picked up in KY a few years back.  Since then I fixed the fuel system and got it running, squared away the suspension (new bushings, shocks, springs, hubs, etc etc).  But that is where my skill set ran out; never welded and never done resto work.  Kept trying to find a shop to do the body work, but never had any luck.  Then I moved and ended up close to a family member who happens to be a retired welder and enjoys doing resto/custom work on cars.  Perfect chance to dive into the Z!  So I bought a set of the Klassicfab panels and we dove in.

The floors/rails started off like so:

Driver's Side:

Driver's side outer rocker looking rough:

Passenger side:

The drivers side was worse, but both were pretty shot.  There had been a previous repair to the drivers side floor pan in 2 areas, and the rail had been reinforced as well.  But both floorpans were perforated in many areas and the rockers on both sides were pretty shot.  The frame rails were also obviously shot. 

First up, we got the car on blocks and welded in some braces. 

Then we removed the driver's side inner and outer rockers and floorpan (scary initially to cut into the car, but that wore off quick), leaving the seat braces largely intact.

Then we welded together the new rockers (inner to outer), and welded the new frame rail to the bottom of the floorpan and tacked those in:

Then we welded those in.. or actually my Uncle did most of it because that is some EXPERT level welding; that steel is THIN

And then a quick check for door fitment.. should have done this after the tacks and BEFORE welding.. thankfully lined up fine (not perfectly lined up here because the bolts aren't tightened yet)

Next onto the passenger side.. same strategy; started cutting out the rockers and floorpan

Nice shot of the 4-layer 'sandwich' that is the rockers+pan+bottom of the A pillar:

And thats as far as I've made it thus far.. more to follow in the future.  What a dirty and laborious job.. but also highly rewarding so far.  I am learning a ton!

-Ben

Edited May 20, 2022 by Neb

[Patcon]

Super progress!!

[87mj]

I am curious how you made sure the welded nuts on the front of the rockers aligned with the mounting holes at the rear of the front fenders?  If those nuts don't align with the holes on the fenders properly, the fenders might not align with the rest of the car.  In my case, the body shop didn't align them properly.   Now the lower fenders stick out much further than the front of the lower part of the doors.  Now I get to start over with another body shop and fresh paint.  😞 

[Neb]

4 hours ago, 87mj said:

I am curious how you made sure the welded nuts on the front of the rockers aligned with the mounting holes at the rear of the front fenders?  If those nuts don't align with the holes on the fenders properly, the fenders might not align with the rest of the car.  In my case, the body shop didn't align them properly.   Now the lower fenders stick out much further than the front of the lower part of the doors.  Now I get to start over with another body shop and fresh paint.  😞 

Well so far I've only knocked out the driver's side and haven't tried fitment of that front left fender yet.  But that is a good point and I will check into that.  For my car, that area of the rocker was completely rotted away so there wasn't anything mechanically holding it on (I used magnets).  That and the tab on the fender itself had also rusted off.  So I figure it can only be better in my case lol.  On the passenger side we will have to be more careful.  I'll try and get a picture when I check fitment for the driver's side fender..

[Neb]

Alrighty here are a couple shots of the bottom of the Driver's side fender and the rockers.  When lining them up, the Klassicfab panels include every detail of the originals as far as I could tell, so we were able to use the profile of the bottom of the A-pillar to line up the inner+outer rocker combo pretty easily. 

Lining up the rockers:

Shot of the bottom of the new rockers+front quarter panel.  Toe box is still a work in progress; previous repair job basically patched that whole area with a much less concave section, so its getting remade. 

Shot of the door+quarter panel alignment.  Door can probably stand to be adjusted forward a bit more here.. but so far so good!:

[Namerow]

Great progress.  It's always nice to have a talented welder in the family!

Can you comment on how you removed the old sheet metal?  Did you drill out spot welds?  Metal saw?  Angle grinder?  All of the above?

[Neb]

11 minutes ago, Namerow said:

Great progress.  It's always nice to have a talented welder in the family!

Can you comment on how you removed the old sheet metal?  Did you drill out spot welds?  Metal saw?  Angle grinder?  All of the above?

Very much all of the above.  Sawzall where we could because its quickest/safest.  Drilled spot welds, then followed with hammer and chisel where trying to preserve the old stuff.  Angle grinder with a cutting wheel where we had to.  Dirty work, but it goes a lot faster after you get your methods down..

[Neb]

Fitment check on the passenger side floorboard and rockers..