Wings: Main spar. Countersinking and spot priming.

Lots of countersinking today.  Did all of the #40 holes in the spar as called for.  Leaves quite a mess.  Right picture is my pant leg!  I went 3 clicks further on the skin holes and added a little pressure (*note, Van's suggests 7 clicks). This should help the skins lie flush in the countersink.

   

Here are all the shiny new countersunk holes.

 

The plans call for the nutplates to be used as guides for countersinking their screw holes in the spar.  Many other builders use a piece of scrap, match drill it, then use that as their guide.  I decided to use that technique on the #40 holes only, using the nutplates for the #30 holes and repriming as appropriate.

Instead of spot priming, since it would take so long, I used Napa 7220 and just ran it down the flanges, using cardboard to prevent overspray.  Here's a shot of the right wing's lower flange.  I had to sand out the few scratches I created with the drill bit, prior to priming.

   

And a pretty shot of a primed, countersunk hole. 

Oh, and don't forget the #40 holes on the tip of the spar.  Keep in mind that those nutplates are attached to the aft portion of the spar, so you need to countersink on the forward part, not the aft!  Don't countersink the screwholes on these!  This was a mistake on my part as I misunderstood the plans.