Aluminum rivet head shape - NCRS Discussion Boards

Aluminum rivet head shape

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Steve L.
    Very Frequent User
    • June 30, 2001
    • 763

    Aluminum rivet head shape

    I'm replacing all of the underbody reinforcement plates and I've noticed that the original rivets head shape after they have been deformed at the factory are not very round. They are more like squashed stumps.

    I'm using a small air hammer with a tool that I've modifed using one of the vendors hammer tools as a guide.

    The head that I can make is a very nicely symetrically shaped round head that I think looks great but it's nothing like the factory shape.

    I think the factory rivet is held in more by expanding the shaft of the rivet than the head ( or lack of head).

    Anyone have any comments on this?
    Steve L
    73 coupe since new
    Capital Corvette Club
    Ottawa, Canada
  • Terry M.
    Beyond Control Poster
    • September 30, 1980
    • 15599

    #2
    Re: Aluminum rivet head shape

    Expanding the shaft is the way steel rivets increase the strength of the joint. I'm not sure that is necessary in holding the underbody sheet metal to the plastic on the Corvette. It seems to me this is more important in skyscrapers and bridges than Corvettes. The upset head may be more significant in spreading the load on fiberglass. I seem to recall some illustrations of various joints in the front of the AIM. It might be worth taking a look at those illustrations.
    Terry

    Comment

    • Chuck S.
      Expired
      • April 1, 1992
      • 4668

      #3
      Re: Aluminum rivet head shape

      Originally posted by Terry McManmon (3966)
      Expanding the shaft is the way steel rivets increase the strength of the joint. I'm not sure that is necessary in holding the underbody sheet metal to the plastic on the Corvette. It seems to me this is more important in skyscrapers and bridges than Corvettes. The upset head may be more significant in spreading the load on fiberglass. I seem to recall some illustrations of various joints in the front of the AIM. It might be worth taking a look at those illustrations.
      First, cut the rivet to correct length for the AIM part number; you won't end up with a lot of material in the peened head that isn't supposed to be there. Second, I know that rivet guns are faster and easier, but I got good results by simply hand peening, with someone else bucking the flat round head using a 3 pound engineers hammer. Even then, your peened heads will be prettier and more symmetrical (over-restored if you like), because you don't have a boss checking on you to see if you're done yet. If you want them to look real, hold your riveting gun at a angle or kind of wallow it around while peening. (only kidding)

      Terry, from my observations, the flat round head of the rivet is typically on the fiberglass side, and the peened end is on the metal reinforcement or part side (I can see the spare tub reinforcement frame riveting as I type). I believe they did it that way to minimize any chance of damage caused by the rivet gun "banging" against fiberglass. The shaft expansion very definitely tightens the joint, but that simply may be an inherent by-product of the peening process rather than being necessary for the joint.
      Last edited by Chuck S.; September 9, 2009, 11:39 AM.

      Comment

      • Steve L.
        Very Frequent User
        • June 30, 2001
        • 763

        #4
        Re: Aluminum rivet head shape

        Originally posted by Chuck Sangerhausen (20817)
        First, cut the rivet to correct length for the AIM part number; .
        Chuck,
        Do you know what the length that sticks out of the assembly prior to peening over should be
        Steve L
        73 coupe since new
        Capital Corvette Club
        Ottawa, Canada

        Comment

        • Harmon C.
          Extremely Frequent Poster
          • August 31, 1994
          • 3228

          #5
          Re: Aluminum rivet head shape

          The rule in the sheetmetal trade is the diameter of the rivet should stick through. I make each rivet this length with a special tool. Assembly line workers should have used what was called out in the AIM. What they used was what the stock boy dumped in the bin if it would work.
          Lyle

          Comment

          • Chuck S.
            Expired
            • April 1, 1992
            • 4668

            #6
            Re: Aluminum rivet head shape

            Originally posted by Steve Lischynsky (36372)
            Chuck,
            Do you know what the length that sticks out of the assembly prior to peening over should be
            It varies considerably depending on the part number used for the joint, i.e. how many layers and thicknesses were being riveted. Go into Doc Rebuild's site; he once had a table there of GM rivet part numbers and the respective lengths. Doc Rebuild sells the longest shank length and you cut them to proper length using the chart. He used to sell genuine NOS aluminum rivets, but I don't know if the supply has been used up or not. I'm sure any repros of his would be very close to original (He made sure the buyer understood the deficiencies of wannabe repro rivets, so he knows his rivets well. )
            Last edited by Chuck S.; September 10, 2009, 09:45 AM.

            Comment

            • John H.
              Beyond Control Poster
              • December 1, 1997
              • 16513

              #7
              Re: Aluminum rivet head shape

              Paragon also has the correctly-configured soft aluminum body rivets.

              Comment

              • Alan S.
                Extremely Frequent Poster
                • July 31, 1989
                • 3416

                #8
                Re: Aluminum rivet head shape

                Hi,
                I put together a rivet list based on the AIM when I was putting my 71 back together.
                The large flat-head list obviously has the most descriptions.
                The first information in each line is the UPC, Sheet Number, and Item Number where the rivet first appears in the 71 AIM.
                The last page (cut in two) contains the 'rarer' rivets like the flat- head counter-sunk and the round head.
                I hope this info helps someone.
                Regards,
                Alan
                Attached Files
                Last edited by Alan S.; September 11, 2009, 07:20 AM.
                71 Coupe, 350/270, 4 speed
                Mason Dixon Chapter
                Chapter Top Flight October 2011

                Comment

                • Steve L.
                  Very Frequent User
                  • June 30, 2001
                  • 763

                  #9
                  Re: Aluminum rivet head shape

                  thanks Alan
                  Steve L
                  73 coupe since new
                  Capital Corvette Club
                  Ottawa, Canada

                  Comment

                  Working...
                  Searching...Please wait.
                  An unexpected error was returned: 'Your submission could not be processed because you have logged in since the previous page was loaded.

                  Please push the back button and reload the previous window.'
                  An unexpected error was returned: 'Your submission could not be processed because the token has expired.

                  Please push the back button and reload the previous window.'
                  An internal error has occurred and the module cannot be displayed.
                  There are no results that meet this criteria.
                  Search Result for "|||"