I took a “Fundamentals of Building” class at Synergy in Eugene Oregon. When I was there Wally showed us some pieces of metal he said might make good bucking bars. They are cut up from the blades of a brush hog mower. One end is tapered to a point. I decided to go ahead and buy one not knowing if I would even like to use it. I had to clean it up some which did not take long. I have not used it for bucking but for the training project I used it to dimple the narrow end of the ribs.
I drilled a #40 hole and then countersunk the hole. At first I was just using a rivet through the part and into the hole in the bar then tapping the rivet with a flush rivet set in the gun but the dimple was not that great. I did have some close quarter dimple dies from Cleveland but the ribs are narrow enough that you can’t get the nail through the dies and parts with enough left for the rivet puller to grab onto. I then got the idea to use the female part of the set with the bar I made. I just set the die over the hole in the bar then put the part on and place a rivet into the hole. (See photos). Then just tap the rivet with a flush rivet set and the gun set to about 15 psi. The opposite end of the bar is clamped to the table, you can see the orange rubber of the clamp in the photos. This seems to make the best dimples, still not as good as a normal dimple set but better than just the rivet going into my countersink in the bar.
Original hole with countersink. Die goes over this hole
You can see how narrow it is, fit all the ribs so far.
