wing rear spar and rib tab dimpling

[pilot2512]

I was deburring and dimpling my wing ribs today. Where the main ribs meet the rear spar at the bottom skin locations there is a tab of the rib. Is this spar and tab dimpled together? I see no way to dimple each piece separately but it sure does feel awfully thick to dimple at once. I was using a hand squeezer. Would a pneumo be better to use?

B.T.W. Them is a lot of holes

[terrye]

The rear spar on the RV-9A is a Z section. I dimpled the top and bottom flanges with my pneumatic squeezer, but I'm sure a manual squeezer would work. The rib bottom aft tab with a single rivet hole was dimpled separately.

The rule of thumb, according to the instructions is to dimple up to .040" from memory and machine countersink thicker than that.