I have the pieces on the way to assemble new fenders for my Cat Sixty. I have done some riveting in the past by heating them and peening with an hammer, not going to do that again. As a kid I did assist my dad a few times driving aluminum rivets in aircraft, my job of course was holding the bucking bar. I would like to buy a suitable air hammer for the 1/4 inch rivets used in Most antique Cat Sheetmetal. My problem is there are many choices in air hammers and little info on what is best suited to drive 1/4 steel rivets. Can anyone offer first hand advice on how you did it or what size air hammer you used. TIA

Steve, I have done a few sets of fenders and seat boxes. I have Chicago Pneumatic 501? It is an antique, but the same as current production. Figure out your grip length. There are several places online to buy solid steel round head rivets from. I made all the tooling out of S7 or 4340/4140. Smaller 3/16 rivets, I buck them up tight and use a hammer. I cherry the bigger rivets with a torch, you have to experiment on a sample piece, so you get the correct result. It does take some time because we don't have the facilities that the factory had.

Good luck, Herb

Steve, Just get one of those cheap $10 air chisels and cut one of the bits off, face it in your lathe and use a ball endmill the proper radius of rivet to form the tool. Make a bucking bar out of a big piece of cold finish steel maybe 2x4x1.5" use the same ball mill on the drill press and drill a shallow hole like the tool.
I've riveted thousands of 1/4" rivets on all the CAT sheet metal I've made over the years.

Great idea Neil, I have to make a couple of sets of fenders and seats for my 30's.
regards
Mike

I assembled the fenders for the Sixty today, I still need to attach the steps after some more bending. Attached is the Trial fit up, I was happy with the outcome.

Fender looks great!
The late George Rankin would bolt the pieces together then remove one bolt at a time and replace with a Rivet. Skinner

Nice work Steve! Did my riveting advice work for you?

There is a difference between air hammers which are meant for driving rivets and air chisels that you would buy at a farm store or Harbor Freight.
www.practicalmachinist.com/vb/general-ar...sel-rivet-gun-86400/