How to Repair Rusted Sheetmetal by Using Patch Panels

How to Repair Rusted Sheetmetal by Using Patch Panels

Our classic cars are cool, but classic is really just a fancy word for old, and old cars often suffer the effects of Mother Nature. The most common affliction is rust. After all, nobody back in the 1960s ever thought these cars would still be around after 50 years. But fixing rust and body rot is a pretty straightforward operation. All you need are some cutting and grinding tools, a few supplies (weld-through primer, welding wire, etc), and the welder of your choice. If you haven’t done this much, then we would suggest practicing on an old fender and proceeding slowly until you get more confident in your welding skills. In fact, practicing on old fenders and body parts is a great way to get good, really fast, without risking mistakes on your precious ride.

And yeah, you could pay a bodyshop to do these minor repairs, but at $75 an hour even a small job can end up costing you hundreds. And unlike a major repair, like replacing a quarter-panel, doing these small patch panels is hard to mess up if you’re reasonably skilled and you take your time. So, follow along as we ditch a small spot of rust on an otherwise pristine 1969 Camaro.

Sheetmetal Cut Rust

01. The first thing to do is carefully cut away the rusted-out area. Make sure not to cut through the underlying metal structure.

Panel Removal Parts

02. This should be the result with the bad part of the panel removed.

Tracing Outline Steel

03. Lay the removed section on a piece of fresh steel and trace the outline.

Replacement Patch Panel

04. You can then cut out the replacement patch panel. It’s OK to cut it a tiny bit on the big side since it can be ground down to fit perfectly later on.

Grinding Wheel Clean Edges

05. Use a grinding wheel to clean up the edges and to remove old paint prior to welding.

New Patch Panel

06. The new patch panel should fit inside, and butt up to the edges of the hole.

3m Primer

07. To protect the underlying metal, we like to give the area a coating of a weld-through type primer from 3M or Eastwood.

Patch Panel Placement

08. With the area prepped, use a magnet to hold the new patch panel in place.

Mig Welder

09. You can then bust out your trusty MIG welder and stitch the new panel in place.

Welded In Patch

10. The welded-in patch is now ready to be ground down and bodyworked.