And just a little more debur and countersink - 3.5 hours

Well this morning I found myself really questioning the dimpling of the inboard ribs. I had dimpled all the holes on the rib yesterday. The plans on drawing #12 to leave certain holes un-riveted for future attachment of the wing root fairing. Well of course I interpret this as dimple it all and not rivet some holes.

So after I did some checking on the forums this are seems to be a bit of a tricky area for some builders. First off the holes noted to be left open do not match between drawing #12 and #38. Next issue is do you not dimple these areas, or do you drill and dimple them now. Well...more reading on the forums and a message sent to Wirejock (Larry Larson) I think I have it figured out.

I've decided that drawing #38 is the correct drawing for locations. Everyone says "about every third hole". Ok...That's settled. Next Wirejock recommended leaving the hole undimpled and keep the #40 pilot hole. He said that I will use these holes to cleco on the fairing later.  Good enough for me!

So...Of course I had to flatten out the necessary dimpled holes on the left wing rib that I had done yesterday. Not a big deal as you typically can flatten a small dimple without structural issue. Better yet, down the road I will have to drill open these holes to a larger diameter anyway so its totally fine in the end no mater what.

Once I had the left wing fixed up. I needed to complete the few countersink holes and rib dimples that where left on the right wing. I then cleaned, masked off the front and rear spar and primed.

While I waited for the primer to dry, I prep'd the right leading edge skin (debur, edge roll, and dimpled) same as yesterday.

Little more debur, countersink, and dimpling - 4.5 hours

I had finished the majority of deburing and counterskinking however there is just a handful of places where I just couldn't reach the end (inside) ribs where my wing stand structure blocks access. I've built a slightly smaller wing stand structure than indicated on the plans to maximize space in the garage. It works, but I have to make some concessions to make it work. ie. I have to climb under the structure to access between the wings. I will have to rivet the skin on the wing, with one wing at a time. And of course in today's work session, I have to take the wing structure off the stand to access a few locations. Not the most efficient setup, but given that I need the space in the garage, this is a totally workable situation.

So I had pulled the left wing off the stand and finished the 6 or so holes that needed to be countersunk, as well as the handful of holes that needed to be dimpled.

Now it was time to countersink the rear spar (top) holes. The bottom ones are very easy to do with the pneumatic squeezer. The top side is another story due to the angle and interference with the rear spar. I've been giving this area some thought for a while, and I figured that my vice grip 3/32" dimpler would do the trick. I tested a couple of holes first and checked with a rivet. The dimple is not as nice as the pneumatic squeezer, but it works.



Once I was complete I pulled out my microstop countersink (having it set up for the main spar I just did) and I started to check the holes. Of course the holes that are dimpled with the vice-grips take some material off. I then checked the bottom of the rear spar that was done with the pneumatic squeezer and little to no material is removed. I decided that this is the correct setting and went to work cleaning up the top side holes on the rear spar.

Next order of business is to clean an prime the spar where the countersink holes are made. The manual indicates that this can be done as a spot prime while countersinking (i.e. when doing the tank screw countersinks) buy I opted to prime the whole face as some builders choose to do. I masked off the front spar and primed it. I had also primed the top of the rear spar where the machine countersink had removed the primer (and where the dimpling operation flakes off the paint).


As I let the primer dry...I moved on to starting to de-vinyl the wing walk doubler. Next operation was to debur. Now at the back of my mind, I had to keep my dimpling operation correct. I had chose to dimple the ribs for the wing walk doubler with tank dimple dies. The idea is that if I dimple the ribs/doubler skin with tank dies, and then dimple the skins with regular dies this will provide slightly better nesting. However....months ago when I dimpled the rear spar....I didn't use this thinking and I dimpled with regular dies. Confusing I know but basically when it comes to the doubler the bottom line for my build was this;

Dimple the rear spar line with regular dies, dimple the rest with tank dies. So...to make sure I mitigate the risk of messing this up at a later date. I dimpled the rear line.
 
Of course it wasn't midnight yet and I was still wide awake...why not do a little more I thought. So whats a little more deburing and dimpling? I took the left leading edge out and debured. Now...most important for me to remember. I used the edge forming tool and ran through to two edges. Next I dimpled.

More deburring and countersinking the wing - 3.5 hours

I decided to use 3/32" tank dies on the ribs and wing walk doubler (with regular dies for the skin). As such I double checked the countersink needed and came to the conclusion that it is the same depth of countersink that is needed for the thicker 0.035" skin. (As the wing walk doubler is 0.025" thick).

I ended up completing all the wing spar countersinks. Wow...what a lot of work. It's fun a first, but becomes very repetitive. I decided to re-tackle deburring for a bit before calling it a night.

Deburring/dimpling/countersink the wing - 5 hours

Well finally to the point where I can get working back on the wings. Earlier in the day I put in an order to aircraft spruce for some cherry rivets to attach the leading edge (also sent an email to vans support to ask about my options) but before I can get that I have a ton of work that can be done.

I need to remove the top skins and go to work deburring all holes, dimpling all ribs and the skins and countersinking the spar for all the dimples.

After I removed the top skins, I started in on deburring. Once I was done with the left wing/top. I dimpled the ribs. I then climbed in between the wings and kept deburring, and deburring and deburring.

Once I had my fill, I decided to do a little dimpling just to see how it was going to work out with dimpling the rear spar and the rib together. Not bad.



Then I moved onto some countersinking on the spar for all the #40 holes. I made absolute sure of what holes need a rivet to sit flush (the top row that connect the ribs but sit under the tank skin) all the holes that need to accept a 3/32 dimple for 0.025" skin (outboard skin) and those that need to accept a 3/32 dimple for 0.035" (inboard skin). After check, check and re-check I settled on a countersink diameter around 0.193" for the inboard skin dimples and then added a couple of clicks for the thicker inboard skins which ended up around 0.202" (give or take).

Countersinking works best and consistent if you go slow... Grrr.

Completed riveting the right wing rear spar - 2 hours

Completed riveting the right wing rear spar to the wing skeleton. All went well. Thank goodness.

Completed riviting left spar ribs - 2.5 hours

I riveted the new rib onto the right spar as well as the few remaining ribs. I then cleco'd the rear spar on and managed to set a few rivets.

Completed riveting Left Wing Skeleton - 2.5 Hours

I riveted the rear spar to the left wing skeleton. Everything went pretty uneventful. I used the flush rivets in the end outboard rib. The rivets are set well, but the rib has a very slight distortion. It's perfectly fine as the material is tight around the rivet, but the outside edge of the rib flange wants to site just proud of the rear spar.


 I primed the flush rivets as the aileron hinge will eventually sit tight against it.

I can see why the instructions tell you to place the manufactured head on the thin material specifically for riveting the ribs to the spars. Of course I made sure that all manufactured heads where placed on the thinnest material. The end outboard rib is the only instance where you cannot do that.
It is important to double check the rivet callouts. I find that the Vans callout's tend to be off by 1/2 size. I'm sure that they are just fine for use, but I chose to set all according to the rivet gauge.

Every rivet was set extremely well, just had to drill out and replace one rivet. Sweet!

Fine tuning the wing-walk ribs (Left side) - 3 hours

Well I performed some surgery with some files on the offending rib #3. I cleaned up the edges with scotchbrite and spot primed the needed areas. I let it dry a few hours then I riveted the rib to the spar.
 
On rib #2 I quickly noticed that the rivet also interfered with the rib. 
 
 I also checked rib #1...yup. Slight trimming needed.   

More riveting wing ribs to wing spars - 5 hours

I hung up the right wing as it is on hold till I order a new W-711-L inboard rib. I decided to start the left side. I back riveted ribs #13 thru #10. Back riveting the ribs #9 thru #1 becomes tricky as you have to be very careful not to damage the top and bottom doublers. It was an incredible pain to try to avoid this on the Right wing that I decided to try something different. I set up blocks to help ensure I don't push the assembly off the table. I then set up a block with a clamp as a bucking bar rest.

I have a second person hold the bucking bar as I shoot the rivet. The rest work extremely well for someone that has no experience bucking rivets. It's very easy to ensure the bar is perpendicular to the work. The result is extremely well set shop heads.

I have to do this kind of setup more often!!  

Seems that I have a small interference on rib #3 left wing with one of the spar rivets. I have double checked that I have the correct rib and correct orientation. Might have to do some trimming. Thought I would post it on Vans Airforce and make sure I am correct before I start cutting.