Bucking Solid Aluminum Rivets - 1960

[Joe M.]

I am trying to figure out a way to buck 3/16" solid aluminum rivets by myself. The rivets hold the power top cylinder bracket nut plates to the underside of the trunk. My idea is to run the two bolts through a flat bar piece of steel, through the trunk floor, and screw them into the threaded nut plate. The top of the flat rivets will be under the bar steel and held firmly in place with the two bolts. Then I can use my air chisel with a self-made rivet setting attachment to peen the rivets.


The rivets I purchased are the same size as the original rivets, but the holes in the nut plates seem to be too large for the rivets. it seems like it would be easier to peen the ends if the rivets just barely slid through the nut plate instead of loose. I did not drill out the rivet holes in the nut plates. Any suggestions? Bad idea?

If I someone assist me, would a 10 pound sledgehammer head laid over the rivet heads be a big enough bucking bar?

[Donald H.]

Re: Bucking Solid Aluminum Rivets - 1960

Joe, I've done a lot of the Al rivets on my 60. I bought an inexpensive pneumatic hammer from Harbor Freight. It is their 3X Air Rivetings Hammer and comes with 5 punches. It seems to be specific for setting rivets versus just a normal air hammer.

There are different sized punches that fit the different size round head rivets. I set my compressor to 18-20 lbs and put the concave punch head on the rivet head and bucking tool on the other end of the rivet. The Al rivets set very easily, you do not need a heavy bucking tool. I generally use the head of a large steel punch. If I can't reach both sides, I've enlisted my wife to help.

Ive used this technique for the round head 3/16" and 1/8" rivers and the 3/26" countersunk rivets. The key is keep the air pressure very low. I have found it easier to let my wife drive the hammer and me holding the bucking bar. They generally come out looking as good or better than the factory one.

By the way, since you already have an air hammer, I found and bought a set of the rivet setting punches (5) on EBay for less then $30.

[Joe M.]

Re: Bucking Solid Aluminum Rivets - 1960

Donald, how much of the rivet shank should extend through the nut plate? Is the rule of thumb 1.5X the thickness of the material the rivet goes through?

[Chris S.]

Re: Bucking Solid Aluminum Rivets - 1960

I set mine with a ball peen and rivet set tool and use a dolly on the rivet head
Works great

[Donald H.]

Re: Bucking Solid Aluminum Rivets - 1960

Donald, how much of the rivet shank should extend through the nut plate? Is the rule of thumb 1.5X the thickness of the material the rivet goes through?

I've done most of the underbody support, e.g. seatbelt brackets, seat mounts, fuel tank strap brackets, etc. I even removed the heat shield in the tunnel on the underside so that I could media blast it and repaint, then riveted it back in. Also did the long support bracket behind the seats that is inside the fuel tank compartment. It's the one that the fuel tank cover and the soft top panel reinforcement screws and bolts to. Mine was so corroded I removed it to blast and repaint.

I've sort of just used my judgment as to correct length and used a pair of dikes/angle cutters to nip the excess on the end of the rivet, then set the rivet. Once it is set you can't tell it was every cut. If you want to get more precise, I found a cross reference on Dr. Rebuild's website where he has listed the various rivets by AIM part number for some of the rivets and the correct length. The 53 - 62 rivets on on the bottom of the page.

http://www.docrebuild.com/dr-r-web/9024025.html

[Alan S.]

Re: Bucking Solid Aluminum Rivets - 1960

Hi Joe,
I found a similar situation on more than a few rivets on my 71... the hole the rivet is to be 'set' in is quite a bit larger than the rivet shank.
I use a small hammer to begin to compress the shank while the head is bucked on the top surface of my vise. I peen and check, and peen and check, until the partially compressed shank is snug fit in the hole. You do need to be careful that you keep the shaft straight and don't lean it over.
I then estimate the length I'll need and trim the shank as Donald suggests.
I continue to set rivets by hand since I don't have an air supply in my garage.
Good Luck!
Regards,
Alan

[Rod K.]

Re: Bucking Solid Aluminum Rivets - 1960

I believe the rule would be based on the dia of the rivet body regardless of material thickness. The gauge I made gave about .250 (1/4) inch, or 1.33d, protrusion beyond the material being riveted. Worked very well on the many rivets I replaced.

[Tracy C.]

Re: Bucking Solid Aluminum Rivets - 1960

I am trying to figure out a way to buck 3/16" solid aluminum rivets by myself. The rivets hold the power top cylinder bracket nut plates to the underside of the trunk. My idea is to run the two bolts through a flat bar piece of steel, through the trunk floor, and screw them into the threaded nut plate. The top of the flat rivets will be under the bar steel and held firmly in place with the two bolts. Then I can use my air chisel with a self-made rivet setting attachment to peen the rivets.


The rivets I purchased are the same size as the original rivets, but the holes in the nut plates seem to be too large for the rivets. it seems like it would be easier to peen the ends if the rivets just barely slid through the nut plate instead of loose. I did not drill out the rivet holes in the nut plates. Any suggestions? Bad idea?

If I someone assist me, would a 10 pound sledgehammer head laid over the rivet heads be a big enough bucking bar?

Joe, You are correct in that the rivets are too small for the hole in that plate. The 1.5 x rivet dia extending before bucking is a general rule for a rivet with a few thousandth clearance. If you buck those with that much clearance you wouldn't get any butt at all. Get a SOFT rivet from Dr Rebuild with at least 1/2" extending out of the plate and buck with low pressure. Your bucking bar only needs to be a hand held body dolly. Holding the plate in place with the bolts is a good idea, but do not cover the rivet heads. Use the bucking bar for that.

good lick,
tc

[Joe M.]

Re: Bucking Solid Aluminum Rivets - 1960

Thanks to all for great advice and tips. Since I had to add new glass to the underside of the trunk, the 3/16" diameter rivets are not long enough. I believe Fastenal sells one inch long 3/16" flat head rivets. They are not countersunk, but that is probably not a problem. I may have to buy a box of 1,000. I think the box price is $5.82 and the shipping is double the price of the box of rivets. I will take a look at Doc Rebuild as well. I would like to purchase them from local source in Dallas area so I can move my project forward asap. I need to get the nut plates re-installed so the power top equipment can be re-installed.

[John H.]

Re: Bucking Solid Aluminum Rivets - 1960

I believe Fastenal sells one inch long 3/16" flat head rivets.

Joe -

Make sure they're SOFTaluminum body rivets; regular aluminum rivets are hard, and are extremely difficult to work with.

[Joe M.]

Re: Bucking Solid Aluminum Rivets - 1960

John, you are about 6 hours late on your response. I was so happy that I found solid, flat head, countersunk rivets in the Dallas area that I did not think to ask if they were soft or hard. I know the answer now. I have been hammering away with a small air hammer with almost no progress. I have tried air pressure from 20 psi to 40 psi and it doesn't make any difference. After 2 or 3 minutes of hammering, the end of the rivet is barely rounded.

I am re-installing the nut plates under the trunk for the power top equipment. There is little room to swing a regular hammer. I practiced on a couple of rivets clamped to the vice and with 20 psi on the air gauge and the weight of the air hammer peened the rivets in about 5 blows; different story under the car. I am using a wife and 10 pound sledge hammer for the bucking bar. I have a solid surface while peening, but the hard rivets are making what I thought would be a simple task, very difficult. I was proud of finding the right size and round head countersunk rivets locally in Irving, TX, but did not ask about soft or hard. At every turn, I am shut down on making progress putting my car back together again. I am so sick of messing with it that I am tempted to put the cover on it and walk away, for a while, a long while. It is sad that I have let the process come to this. It is not the car's fault.

[William C.]

Re: Bucking Solid Aluminum Rivets - 1960

Take a deep breath, order some soft rivets, it is worth the wait, plus it sounds like you need a break for a couple of days...

[Paul J.]

Re: Bucking Solid Aluminum Rivets - 1960

...different story under the car. I am using a wife and 10 pound sledge hammer for the bucking bar.... At every turn, I am shut down on making progress putting my car back together again. I am so sick of messing with it that I am tempted to put the cover on it and walk away, for a while, a long while. It is sad that I have let the process come to this. It is not the car's fault.

Joe you're quite the comedian. I'd be careful with any jokes as that size of a bucking bar can do some damage...to you.

Don't forget that this is supposed to be fun. When you get frustrated, walk away for however long it takes for rational thought to return and to reason it out (even if it's days). Sometimes I'll sit down in the shop with my favorite beverage and think through the problem (when I'm not going to use power tools any more that day).

I remember the advice of the late John Muir. I too, have nice tools because I don't take my frustrations out on them and know when to get up and walk away.

Paul

[John H.]

Re: Bucking Solid Aluminum Rivets - 1960

At every turn, I am shut down on making progress putting my car back together again. I am so sick of messing with it that I am tempted to put the cover on it and walk away, for a while, a long while. It is sad that I have let the process come to this. It is not the car's fault.

Joe -

Take a little break and watch a race or a football game - when the correct SOFT rivets arrive, you'll be so pleased with how quick and easy it is to set them, you'll want to do some more.

[Joe M.]

Re: Bucking Solid Aluminum Rivets - 1960

Bill, thanks for good, actually great advice. I do take breaks for a couple of days, but the issues I am having are the same when I go back to them and I am out of other options to try. I got the hard rivets peened enough that they held the nut plates in place so that I could get the bolts started and tightened up. I don't plan on taking the power top mounting bolts out again.