Installing rivets: pre-heat or cold!

steve hackel

steve hackel

Senior Member
Based on your experiences with body rivets for sub rails, door sills, floor
pans and any odd brackets, do you heat them up or try to install them cold?

I do have an aircraft rivet gun - not a muffler tool - and the correct tools

for forming the rivet heads, but even getting them to fully compress much less form a correct looking head is nearly impossible. I'm looking for someone

that has been successful with their installations using either method, and

not just what might seem normal .... :o Thanks, Steve
 
As aeromotor said, they must red hot and bucked up properly. I use a ballpene hammer of the proper size. I don’t know if an aircraft rivet gun is strong enough. I might be wrong as I thought aircraft rivets were aluminum, your call. Practice on a couple of scrap pieces until you eat the hang of it. Keep the rivet hot and make sure you have the rivet bucked up solid.
 
I put rivets in the majority of my floor and subrails with cold rivets. I bought a used, US-made aircraft rivet gun off Ebay. Worked much better than an air chisel.

Next time, I will do them hot, but it didn't seem to matter this go around.

The way I did it, it is a two person job. Someone holding the buck and another working the gun.

I would suggest getting some clecko clamps to keep things in place as you move down the line.
 
The rivets for floor pans and subrails are relatively soft and can be set cold with a good rivet gun and proper bucking tools. AS Tim says above, it's a two-man job.
 
I use my 5X gun (5-inch barrel) for the big rivets and the 3X for the aircraft AD type aluminum rivets. I drove steel type rivets or riveted components as large as 3/8" with the 5X. They make longer ones too but that's getting out of the aircraft inventory since aerospace tooling changes to different types of fasteners when they get much over 1/4".

Bridge and building steel rivets were driven with extremely large pneumatic guns but they were all driven hot back in the day. Few things are constructed this way in the modern era. Ford used big hydro-pneumatic squeezers for most jobs. They always had tooling to speed things up. I get a kick out of watching old movies or the rivet heater guy tossing a fresh hot rivet to a worker with a catch can. The worker would then used tongs to put the rivet in the hole and then he would hold the bucking bar while the riveter guy would drive the rivet. Those guys worked pretty fast too. A lot of their stuff is still standing.
 
Remember just upsetting the head for a good appearance is not satisfying the purpose of riveting. The shank section of the rivet must upset or flow radially to achieve the proper component joining strength. I would research the correct rivet material spec. to use, tools to use and the preconditioning of the rivets.
 
The important result of whatever technique you use to drive rivets is that the rivets fill the holes with no inter-layer expansion.
I have tried using a 3X rivet gun and two different size rivet squeezers (AKA lobsters) to drive steel rivets in Model "A" frames without heat. Hole filling was uncertain, so I strongly recommend heating the rivets to cherry red.
 
Bob
Agreed…I’ve had same results. Other than heat, the next big thing is that it is an2 person job. Especially on the buck.
 
I sold Thomas School Buses for over 30 years. Until they switched to the current C2 body style, the entire body was riveted together. All the rivets were cold bucked at a very high rate of speed. The guy with the bucking bar was inside the body and the guy with the air powered bucking tool was on the outside. It was unbelievable how fast the third guy could install the rivets while the buckers kept up to him. These buses had thousands of rivets to meet FMVSS joint strength. Now the process is mostly done with high tech epoxy.
 
It would be interesting to see how Ford put the frames together. I suspect that they had large rivet press tooling to set the 1/4 inch and especially the 5/16 that secure the running board supports. Workmen likely assembled the frame either in a jigg or used quickly removable fasteners like clecos or bolts to hold the frame together for riveting. I've noted that the frame rivets have round heads on both sides except for the six top rail rivets of the front cross member which had flat heads for fender clearance. The workmen either had to manhandled the frames or they had tooling to pick up and move the frames from station to station. I'd love to see that process in film or photo format.
 
In mass production, they use machines to drive rivets that produce hi-energy to assure there is hole filling when rivets are driven cold. That amount of energy is not available to the restorer, so heat them!
 
They would need to be kept hot while working them, not preheating. If you heated before installing, they would chill too fast to be of any use, esp a small rivet that you are taking about or even a frame rivet.
 
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