One of the first things we decided to do when we got our ’75 Laguna project car was to narrow the bumper, and pull it close to the body. That involves a lot of cutting and welding. While we were at it, we removed the thick rub strip, and filled all the holes. There were a bunch of them, and they looked ugly. Having tried my hand at welding many times in the past, I knew it would be folly to try and fill such large holes with standard techniques. Luckily, Ricky Jackson, the proprietor of Ricky’s Customs and Restorations (where our car was being painted) had a little trick up his sleeve that he showed us. We think you should know about!
We filled all the holes in our bumper with perfection. The result: no burn-throughs, no buckling, or any other kind of surface distortion resulted—and it was really easy. After grinding away the surrounding chrome plating of the bumper, take a thick piece of copper sheet—it needs to be big enough to cover the hole in question—and bend a small tab at the end. Grip the bent tab with some vice grips, and hold the flat surface of the copper piece under the hole while you fill it with your MIG welder. The molten metal will pool on top of the copper, while fusing with the steel in the bumper (or other work, such as a body panel). Don’t worry, it won’t melt your copper. When the filler cools, just yank the copper piece off with the vice grips. The steel filler will not weld to the copper (the copper repels the molten steel like water on wax paper), and the copper will not yet the molten steel leak past. It’s a great trick, and yields a perfectly flat stack-o-dimes right over your piece!