After reading Mike Smith's post on Sonex Builder's Net and recalling my own life experiences with aluminum thread galling, I concluded that adding Time-Sert thread inserts to the AeroVee would be inexpensive and prudent.
Removed right side head, cut and installed Time-Sert 42123 M12 X 1.25 X 15.0 SP TIME-SERT (WASHER SEAT) from Thread Kits Company.
Thanks to Mike Smith for the loan of his installation tool!
