I am still working on my wife's Metropolitan, I split the bumpers to give her a sexy rear. This should work the same for most bumpers. The bumpers are out at the chrome shop, I hope they look good after plating. This is an old photo of her car's rear. This is how the bumpers looked before plating. If making a decision to split bumpers a few things should be considered first. Looks are tops, try to photochop a photo, look at other cars, does the car have a rolled pan to fill the space covered by the bumper, will you need to make a pan ? Are there any other cars that can donor a split bumper? Edsel, Vette, Camaro SS, 55 Pontiac, Opal GT, 55 or 56 Buick, many Cad, 57 Dodge lancer, 58-9 Imperial are all good bumper canidates. I guess you should also think about safety. I went with the stock rear bumper and split it myself, I could have used a Met front bumper, but the bolt holes are in a different location. My choice to use the rear had other issues, the bumper curved out around the spare tire and had good chrome that I had to remove. The chrome and copper need to be removed to get a good weld. A peeling old rechrome bumper would have been less work to strip, more on that later. I have many photos to size and host on my website for this tech, keep looking for updates.
Here are a few photos and tech, before I go to surf porn. Here you can see how the bumper profile is, it curves in a bit at the bolt hole, I will deal with that later. I used a chop saw to grind a section out of a core bumper, for the straight part of the bumper, lucky for me that the front Metro donor bumper is the same radius profile as the rear. You can use a hacksaw/sawsall/wizzer/plasma to cut with. The radius of the section needed a little tweak to match the end of the bumper, you could use just about anything for a anvil, pipe/roundstock/treestump. Test fit often, fit cut with beltsander. Now I will show how little I know about Chrome, I hope some expert will jump in and help. I have heard that a plate shop can strip the plating off, but I am allways late and in a hurry, I first tried to sandblast the good chrome off with that black lung oxide stuff, it did work, but it took forever, you can see in this photo. Blasting worked better on the old peeling donor section, I think I had better luck with a DA and 40 grit, cutting down to the gold color, then sandblasting the rest off of the good chrome. It took hours it seemed, but I would have waited weeks for the chrome guy to strip it. In the photo above you can see the layers of plating, bare steel by the cut, gold/copper layer on top the steel, all must be taken off for a good weld.
I started to TIG the bumper together, but I got lazy and used the MIG. The TIG would give you a weld that would be less likely to crack when hit, I used the MIG to help fill a few low spots and the larger fillet bead was also a bonus. Here is the part I used for the tip of the bumper. The cut line was scribed on the scrap bumper with a surface gauge, you do not need a surface gauge to get a straight parallel line on the part, place the bumper on a 4x4 and find a block the right thickness and hold a scribe on the block and slide it on a flat surface while scribing the line.
Line up parts and find length that looks good. The tip needed a tweak on the profile radius to match up with center splice. This photo was taken on my low tech anvil
man, that's gotta be the most work ever put into nash metro bumpers! something just occured to me...did you once have a NSU Prinz?
Great Tech. Alot of work and heating and bending. What is that anvil you using? Is that something homemade?
Ray, ? NSU ? WTF, is that some kind of moto bike ? Chop50, The only anvil in the photos is called a Pexo Blowhorn, it is a old one I picked up someplace a long time ago. The bumper was not heated up and bent, it was all made form parts of old bumpers I had on hand. Back to the tech. With the bumper all welded up, I can now deal with the low spots and the slight dip on the outside surface by the bolt hole. Off to the tree stump anvil to "bloat" out the low spots with a ballpeen. A leather glove and earplugs are suggested equipment, for this operation. The stump is red oak, but I think any other kind will do Next I filed the high spots to see how much more was needed to raise the low spots. I did remove some metal with this process, but the bumper is plenty thick. The low spots can be seen in this photo, bloat her out some more, grab that flat bastard by the tang and get er done. A note about hand filing, use a file card to keep that bastard clean, the teeth can load up and gouge up the work. Blackboard chalk can be put on the surface of the file to help keep it from loading up (this also works good for aluminum), if you are close to flat with the file work, draw file it. Draw filing is holding the file accross the surface and pulling it forward and back, this will remove the least amount of metal. A few laps around the belt sander and they are ready for the plater.
The Jalopy Journal
