How to fabricate your own brackets using a hammerform

1. Good news: This fiberglass bumper weighed in at about 5 pounds, helping us save some critical weight from the nose of the car. But the bad news: The new bumper didn’t include any mounting brackets.

2. The backside of the piece was simply hollowed out, so our new brackets would need to fill this void while mating to the car’s OE bumper mounting points. 

3. We started fabricating the brackets by making a template with a file folder, scissors and some tape. With a little trial and error, we quickly had the shape we needed.

4. We held the bumper up to the car to determine the depth of our templates. 

5. Using the first template, we created a new template with 1-inch mounting ears.

6. The first template was then used to make our bending tool out of two pieces of scrap plywood: a hammerform. Each piece of wood is cut to the same shape, with the hammerform serving as a low-tech die. In a few steps, we’ll clamp our sheet metal inside the two pieces of wood and hammer the mounting ears 90 degrees.

7. Next, we used the second template to mark our cutting and bending lines on a piece of 20-gauge sheet metal.

8 + 9. After using a center punch, we drilled 1/8-inch holes at the corners of our necessary bends. The bumper and bracket will probably vibrate and flex a little, so these holes should help stop any cracks from forming.

10. We trimmed the sheet metal blank to its final shape with shears.

11. We spent a little time with a sander radiusing all the corners to avoid stress risers and prevent any sharp edges that could cut someone.

12. We could now attach the two pieces of our hammerform to the bracket using screws. 

13. We clamped the hammerform into a vice and bent each tab over it using a plastic hammer. Any hammer would have done the job, but the plastic one doesn’t mar the part. We bent the sheet metal in steps, too: first to about 30 degrees, then to 60 degrees, and finally, all the way to 90 degrees.

14. We’d eventually make four brackets to attach the bumper to these factory mounts. We slotted the stock mounts for up-and-down adjustment.

15. We clamped our first bracket to the mount and, after test-fitting, marked the necessary holes with a permanent marker. The goal was to place the bumper’s height in the middle of the adjustment range.

16. After correcting for marking our holes slightly off center, we used a step drill to put 5/16-inch holes in each bracket’s mounting tab. 

17. Here’s the first bracket, finished and bolted up.

18. We repeated the process for the next three brackets.

19. We made brackets for the sides of the bumpers with a similar process.

20. With the brackets finished, we fitted the bumper, drilled it for 3/16-inch rivets, and got out our rivet tool.

21. All finished, the bumper fits well after just a few hours of work.