Wing Skin Wing Root Fairing Holes

I'm in the process of prepping the bottom wing skins and I'm confused about the holes that are used to mount the wing root fairings on the inboard skin. On drawing 12 it shows every other hole on the inboard line of holes as taking a countersink rivet, but it doesn't say what to do with the other holes. There is a reference to drawing 38 and I can't figure out what they are trying to show in the installation detail. Do platenuts go in those holes? I'm not sure what to do at this stage. It almost seems like I should only be dimpling ever other hole. Is this the correct way to handle it? I've already dimpled all the holes in the inboard ribs and the top skins.

Sounds and looks more complicated than it is

Ray,
I have been reading blueprints for a living for about 55 years, and this is a little confusing to me as well. I am in the same boat as you, I dimpled all the holes too, but did remember to leave the rivets out.
The view on drawing 38, over on the right side, is what we used to call a "developed" view, in that it essentially takes what is actually a curved or bent surface, and rolls it out flat. So, the view of the left wing skin is as if you removed the entire skin from the wing in one piece, unbent the leading edge, and laid the whole thing down flat with the inboard end to the right, outside surface up, the top trailing edge toward you, and the bottom trailing edge away from you (i.e., at the top of the drawing in the view on dwg 38). It is a little more confusing then because all but the last couple of inches of the right (inboard) end is then "cut off" and discarded, leaving the view shown on dwg 38. On the tank portion of the drawing, the plate nuts are all in new holes that are not yet in the tank skin, so no worries there about anything you did or did not do with them. On the holes in the skin rearward of the spar, they will be opened up for the no. 8 screws, which will remove most or all of the dimple, and you will then be re-dimpling or countersinking for the AN509 8R8 screws. To orient yourself a little better, note that the screws on dwg 38 that are shown as small triangles are the existing most inboard screws on the tank skin, which will be removed and reinstalled as part of the attachment process.
If you go to the top center of drawing 38, look for Section GG, and it will give a better picture and more insight into the orientation of the platenuts and screws, relative position of wing and fuse skins, fairings, etc. This view is looking forward through the left wing root.

Hope this helps.

The bottom fuselage skins overlap this joint and are secured with flat head screws during wing installation. The root ribs get platenuts along the bottom of the rib.

My recollection is that the platenuts are the countersunk type, which means the skins and ribs will need dimpling or countersinking to match. Check the part number callout on the platenuts to be sure. I know that on the -6, it calls for countersunk platenuts.

Note that it's not uncommon for these to be missed in construction, right up to the point of final inspection. I caught this on a local builder's RV just a couple of months ago when he brought the parts out to the hangar for the first time.

Ok. I too am pretty good at reading blueprints from my work but these are just missing a couple of notes to make it easier. From the Legend in drawing 38 I can see the countersink platenuts shown for bottom skin portion. I think they were trying to show them placed every third hole in the drawing. Maybe this was changed later on the skin drawing. I think I have the idea now. Clear as mud as they say. Thanks for the help.

Another discrepancy

I just noticed that there is a discrepancy on the bottom inboard wing skin between drawings 12 and 38. Drawing 12 shows every other hole with the rivet left out, total of 10 holes, but 38 shows every third hole with the rivet omitted, total of 8. I checked the bottom fuse skin to see which one of the schemes its holes matched, fortunately there are not any holes there, so they can be drilled to match. I went with the 10 holes.

I only have the smaller drawing 38 from the plans book so its hard to see the details but that was what I was referring to in my earlier message. I decided to leave the skin un-dimpled for now in those positions.

I didn't like the idea of measuring and drilling these holes. What I did was to wait until the wing was on and after I drilled and bolted the aft spar I was able to pull down on the overlapping skin just enough to slide a hole duplicator in and drill them. Once the wing was off I added platenuts.