One of the biggest problems we have to deal with when it comes to old vehicles is Iron Oxide, aka rust. This stuff, if not dealt with, will literally eat your car away to nothing. Because we primarily talk about classic muscle cars in these pages, its pretty much guaranteed we will see a lot of rust. Case in point is a 1970 Z28 Camaro we have been wrenching on. The car is pretty dang solid, but the driver's side quarter-panel has some serious rust going on. We like the car and want to keep it around, so it was time we bit the bullet and got busy fixing the quarter.
We have been around body and paint shops long enough to know that a full quarter replacement is pretty involved, but nothing a person with some common sense, a welder and a few special tools couldn't handle. We think we fit that bill, so instead of passing off the work to a shop we decided to roll up our sleeves and try it ourselves.
The job will take some special tools to complete, most notably is a welder. We have an older Lincoln SP-100, 110-volt wire feed that handled the job great, but those have now been replaced in the Lincoln line with the Power MIG 140. You will also need some special clamps, a grinder, a cut off wheel, and some blocks, but those can all be ordered from Summit Racing. There were some items we didn't have on hand for the job, like body filler and sand paper, which we were able to get in one stop at Summit Racing.
The key component to the fix is going to be the sheetmetal, and we decided to go straight to Auto Metal Direct (AMD). We ended up ordering a quarter-panel and some supporting pieces, which we'll go into more detail about later in the story. We have all heard the horror stories of what some body guys have had to do to make lesser quality panels fit, but in our case it all fit, which made the job for rookies like us doable. This was the most involved bodywork job this author had ever done, and thankfully I did have some help in the way of our local electrical guy, Lucky Costa. I will say that I consulted a few professionals for advice on how to do a few things, and we got a few different opinions. The following story is the route we decided to take, and it came out great, which probably has more to do with good parts and less about skilled labor.
Our subject vehicle is a '70 Z28 that (obviously) has some serious rust issues. Not only is the quarter covered in some pretty bad surface rust, but the front and back of the wheelwell are beyond saving. The car was put out to pasture, so this rust was never stopped and now it's too bad to fix with just a couple of patch panels. We already know that we will be using an AMD quarter-panel for this repair, but we need to get the original quarter off to know the full extent of the rust damage and if we need any other supporting pieces.
Step one is to unearth the factory roof-to-quarter seam and remove the lead. After sanding off all the old primer, paint, and body filler, we found our lead to be removed. We decided to melt it out with an oxygen acetylene torch instead of trying to sand or grind it out. We kept the torch moving so we didn't put so much heat into the panel that it would warp.
We used a few different tools and procedures to get the bulk of the quarter off. In the areas where the quarter has a sharp edge (like the rear window area) we used a grinder to cut off the corner, and a putty knife to open up the separation. This leaves the welded joints intact, but makes getting them off much easier later on.
For the bulk of the removal, we used an air chisel with a cutting tip to quickly cut the metal. We could have also used a plasma cutter, air saw, cutoff wheel, but this was the quickest. We made sure to stay away from the edge at first to prevent hacking up anything hiding under the quarter.
After consulting with a few body guys, we decided that we were going to butt-weld the roof seam instead of trying to slip the quarter underneath the way the factory did. We carefully made a straight cut along the old quarter with a cutoff wheel. Now we could address all the leftover remnants.
Back at the taillight panel area, the quarter is held on with a few small spot-welds and seam sealer. Some wiggling with the pliers was all it took to break it free leaving the taillight panel intact. This would not work if you tried to get the quarter off in one solid piece, so maybe now our reason to quickly cut off the bulk is becoming clear.
The majority of the welds holding the quarter on are made with a spot welder, so we used a spot weld cutter to remove the material. These cutters work by cutting around the perimeter of the spot-weld, allowing you to remove the piece with minimal damage to the underlying metal. Cutters like theses are available at Summit, but we already had one.
After using the cutter on all the spot-welds, all we had to do was pry up on the piece. There will be small round discs of old quarter that are left behind but these are easily ground off, but more on that later.
There is an area where the spot-weld cutter just wont fit, and it's in the gutter of the trunk seal. We used a cut off wheel to carefully grind away the spot weld being as careful as possible to not grind away the lower metal we are trying to save.