How to install rocker panels on a Shoebox Ford
There are parts you expect to change on every serious project. If the car has led a normal or abused life, the rocker panels will always be one of those areas. The simple nature of the rocker panel lends itself to an early demise from automotive cancer. Years of water, mud, leaves, and rocks kicked up by the front tires, that find themselves trapped for next 50 years, will always turn to rot. Sure you can stave off the rust by cleaning them out occasionally, but not many people do this and it just isn’t possible to get it all. The result is the same, replace them with new or repair them.
This car had been sitting in a barn for 30 years before it was sold on Ebay to a Kansas buyer, after he got scared (this car was not in great shape, even I had my concerns) it was sold on Ebay to a man in Claremore, Oklahoma where it sat for a year untouched. While searching the infamous global marketplace for a new project, I came across the car, again on Ebay, and purchased it for $500. Had I known the car had exchanged hands so many times, I might have reconsidered, but I am always up for a challenge. The inner and outer rockers were completely shot, needing total replacement. Since our shoebox is a popular vehicle, there are aftermarket replacement panels available, so we can simply replace the entire rocker panel, inner and outer.
The process is straightforward. The spot welds are drilled out, a little die-grinding and the rockers usually come out. The shoebox we are working on is a little different. Because the floor had gone the way of the Dodo eons ago, we needed to brace the body before the rockers were cut out. If left alone, the body could bow, causing a whole host of problems and the car would be crusher fodder for sure. A piece of 1” square tubing was welded into the door jamb to accomplish this task. Once the original pieces were removed, the new inner and outer rocker pieces, from Mill Supply, were prepped with some weld-thru primer and undercoated on the inner sections. The weld-thru primer is an important step that is typically forgotten. Weld-thru primer is a high-zinc coating that prevents the new welds from rusting. This is done to protect the areas that become inaccessible once the job is completed and can’t be painted, cheap insurance for your car. The edges get weld-thru primer, the rest get undercoated. We welded the two pieces together outside the vehicle and installed as a single part, which requires less welding and saved time. Once installed, we used a grinder to clean up the welds and then coated them with seam sealer.
That about wraps it up, the new rockers are in place and now we have something to weld the new floors to. The new parts from Mill Supply come coated with a rust prohibitive coating that protects them while they are sitting in a warehouse. That is good news as they will be on the car as is until the rest of the bodywork is completed.

1. Before any cutting could be done, the body needed some extra support. This is not normally required when the floors are intact, but this car was so far gone, we felt it necessary. The doors were removed to make things easier, but this step is not absolutely required.

2. The brace was welded to the inside edge of the door jamb. Just a few tack welds to hold everything together.

3. Jordan Lewis of, Ramsey Auto Body, used a die-grinder to separate the rocker from what was left of the floor pan.

4. A sawzall made quick work of the center section of the rocker. Doing this allowed more room to work.

5. Using a spotweld cutter, the factory spot welds were cut out. This is a lot faster than drilling.

6. Separating some sections of the old rocker required an air hammer and a chisel. Care must be taken here as it is easy to tweak the surrounding metal.

7. As seen here, the old outer rocker is trashed. The new piece from Mill Supply features all of the correct stampings and shapes.

8. The inner rocker was not in as bad shape as the outer, but it needed replacement. The new pieces have rust preventative coating, which is a nice touch.

10. The edges of each panel were then sprayed with a weld-thru primer. This protects the metal and new welds from rusting after installation.

11. The rest of the inside sections of the panels were treated to a spray of undercoating. This will protect the panels from future rot.

13. The inner and outer panels were test fitted before any welding took place. The build tolerances on these cars were not very tight, so slight trimming may be involved from time to time.

14. Using a punch\flange tool, the inner rocker was punched every 3-4”, creating holes for the spotwelds.

15. Then, with everything aligned, the inner and outer panels were clamped together and spot welded in place.

23. The seams were coated with 3M seam sealer. This ensures the edges of the panels are sealed from moisture and protected from rust.

25. All done, ready for primer. The rockers will wait a while until the rest of the bodywork is done, so the factory rust coating will keep them safe till then.
Sources
Mill Supply
https://www.millsupply.com/index.php
Ramsey Auto Body
(405) 743-3107