Quote:
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Originally Posted by Zeppelinium
... It turns out that the original Airstream rivets, 1/8" round head, are no longer available. In order to get a head that has a similar diameter and crown shape, you need to get 5/32 rivets. Rivet type is MS20470A5-X, where
MS20470 -- airplane, aluminum, defines the right head shape
...........A -- soft, use for patches and low-load structure. Use
..................a harder rivet for skin to stringer or higher load
..................skin-to-skin connections, use "AD". These buggers are
..................harder to drive, let me tell you, but not that difficult.
...........5 -- 5/32 diameter
...........X -- length in 1/32", should be 1.5D protruding through all
..................layers, before bucking. more on computing X after I ask
..................for "further clarification" from the master.
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Oops, the info for the last digit (the X above) is wrong. Here's how X is determined:
The rivet shaft length (X in the above quote) is measured in 1/16ths of an inch, not 1/32nds. You need 1-1/2 diameters to stick through your material (1.5D, in the vernacular of rivets, which for a 5/32 rivet is 1.5x.156=.234). So if you're putting two sheets of .032 together, you need 0.064+0.234=0.288, which in 1/16ths (0.0625) is 4.6, rounded up is a -5 rivet.
For heavy stuff like a window frame (which my eyeball says is 3/16ths thick) riveted to the shell (which is .032), it would be .234+.032+.188=.454, or 7.3 sixteenths, a -7 rivet.
Aerowood recommendgs getting rivets on both sides of the computed length, particularly on the long side, since a little thickness in the Vulkem or a shim here or there can be accommodated. I think I'll be getting -4s through -9s.
Zep
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