I think Joe's example holes were a little over sized for the rivets.
My first spar took 35 hours to assemble, cleco and rivet. The second one went faster. I made 3 jigs out of plywood to keep the upper and lower spar caps the correct width apart, while allowing the bucking bar to rest directly on my concrete floor, and at just the right height to keep the spar level over the bucking bar. I would caution to ALWAYS do this method on solid concrete. It requires less blows, and makes a better rivet set. Working on top of a table is not rigid and solid enough.
Jig:
http://www.mykitlog.com/users/display_l ... 32&row=260http://www.mykitlog.com/users/display_l ... 42&row=257 - more examples if you scroll forward
These photos show the spar on my work bench. It took about 2 rivets to figure out that sucked, and I moved the assembly down to the concrete floor, which produced far superior results.
http://www.mykitlog.com/users/display_l ... 64&row=250Rivet tape to hold the rivets in place greatly sped up the process!
http://www.mykitlog.com/users/display_l ... 20&row=249http://www.mykitlog.com/users/display_l ... 88&row=247And here I am on the concrete floor. Notice the hearing protection, as the process creates an ear piercing sound with each blow.
http://www.mykitlog.com/users/display_l ... 32&row=248http://www.mykitlog.com/users/display_l ... 67&row=246