I am in the process of installing some rivets in the frame of a 1928 Essex. The rivets are 5/16 inch diameter. I am having a 50% success rate. We are having two problems: 1) the head forming tool wants to drift off center which results in a head that is not concentric with the shank of the rivet; 2) the rivet is cooling before the head is completely formed.
We are using a Chicago Pneumatic CP 715 Zip gun with a rivet tool purchased from Big Flats Rivet. We are using a bucking bar that weighs about 12 pounds. We preheat the area on the frame around the rivet hole to minimize the amount of heat drawn out of the rivet, the rivet goes into the hole bright red, and yet we are still having a hard time getting the head formed. The problems areas tend to be where we are going though three pieces and the rivet has a relatively long shank. The problem may be that our pneumatic hammer is not delivering enough energy to the head with each strike.
Any suggestions on how to improve our success rate would be appreciated.
My understanding is that rivets have to be white hot. Is there anything wrong, apart from originality perspective, with bolting it together?
Installing bolts would be quite sufficient. The only reason for riveting was to repair the frame in the same manner as it had originally been fabricated. Your point that rivet that the rivet needs to be white hot is spot on. Jim Dix at Big Flats Rivet Company suggested that I increase the air pressure to my pneumatic hammer (went from 80 psig to 100 psig) and that I get the rivets hotter. I also warmed the frame a little in the area of the rivet because the 5/16 rivets do not have much mass and cool quickly once the torch is removed. The increased air pressure and heat improved our success rate. Like welding, this riveting process is a practiced skill. The Big Flats Rivet Company website has a two page instruction sheet that covers all the basics for anyone who wants to attempt riveting.
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