The next big project I took on was to repair the rusted / rotted out rocker panels. This was courtesy of 3 year’s worth of Michigan winter road salt I think some sort of mud flap / splash guards would have helped prevent this – even though I’ve read nothing butt negative comments about having them on a ZJ here.
And I drove it like this for a week – afterwards I realize how lucky I was in that I didn’t get stopped by local authorities.
I stripped the front end down, removing the front bumper cover, grill, fenders to get a good look at the damage underneath. The lower portion of the driver’s side fender was completely gone at the mounding points. I scored a complete replacement fender at a local parts recycler yard for $35 – and they pulled it for me. The only problem was it was black and my ZJ is green. I was going for lowest possible overall cost – so I decided to patch the lower half of the black fender to the upper portion of my original fender. The weld would be covered by the cladding. I planned to cover the rocker panels with truck bed liner, so I’d just blend the new portion of the fender by painting it black over the primer.
To fix the rotted areas of the rockers, I first stripped as much of the rust/rot away getting down to good metal. I dug out the inside of the rockers with a pick and air compressor. I made sure it was dry, and then I filled it with expanding foam. The foam would provide a backing for the Bondo fiberglass filler. I thought about using the fiberglass panels to bridge the gaps, but since I’d never worked with bondo or fiberglass before, the foam seemed like an easier route.
Here’s the foam filler:
Once the foam had set, I trimmed it even with the rocker surface, then mixed up and applied a couple of coats of the bondo long fiber filler. I sanded down each layer between coats using a 3m type pad on my right angle die grinder. I scuffed the entire rocker panel front to rear, and then taped off an upper boarder just inside the door sill. I picked up a quart of Herculiner and application kit at Autozone. I went with the Herculiner brand because of cost and they sell it in an aerosol can as well – which I thought would be good for touch up in the areas I couldn’t get with the roller.
After first coat of bed liner – I did 3 coats total:
I worked on the fender in between coats of filler on the rockers. I clamped the patch panel to the original fender, marked it off with some overlap to use as a flange, and cut it. I clamped it together, and then stitched it together with my mig welder. I did 3-4 tacks at a time to keep the panel from heating up too much to avoid it warping.
Fender with new lower section tacked on:
More to follow…