Completed deburring horizontal stabilizer parts and began dimpling spars and ribs. Took help from Brad Smith and Jim Durnil to dimple both left and right horizonal stabilizer skins (HS-801PP). Encountered an issue with getting the C-frame arbor into position for dimpling the forward most rivet hole in the center rivet line of both sides of both left and right skins. After inquiring on VAF forums, I used the 3/32 pop rivet dimpler to dimple these holes. Finished prepping horizontal and vertical stabilizer parts for priming.