Left Wing - Leading Edge & Top Skins

Another couple of days of work in the books.  Because the right wing is on hold until I get the replacement rear spar in hand and rebuilt, we swapped out the right wing for the left wing on the stand.  The left wing leading edge went together a little easier than the right side, probably mostly due to experience.

We put the leading edge on the spar and started the horrible task of riveting the ribs to the spar.  Wow, that was awful!

The rivets definitely aren't perfect, but given the difficulty with access, I think they're pretty darn good!  I think I'll order a borescope - having an easy way to check rivets that are 3 feet back in dark spaces will be really handy.

The top skins were next.  I got to pretend I was busy while Dad clecoed all of the skins on, then we started riveting.  We ended up back riveting as many rivets as we could, and I'm glad we did.  The skins turned out great!

Left Wing - Leading Edge & Oops

I've had some help in the shop this past week!  This post covers a couple of days of work on the left wing.  To get our feet wet with riveting, we tackled the left leading edge first.  I was very happy with the results!  Riveting with a partner is easier for certain things and harder for others, just depending on the position of parts.  I think in general the quality turned out higher by having two people working together.

After the leading edge was done, we got to work on prepping the spars on the jig.  All of the skin attach rivet holes needed to be countersunk, all of the rib holes deburred and dimpled, and the rear spar dimpled.  This is where an oops snuck in.  A miscommunication on where to stop dimpling the rear spar caused the pneumatic squeezer to get caught on the doubler and slam into the rear spar flange.  It was a shocking amount of force - it caused the dimple die to actually cut through the flange!  I thought it might be fixable by cutting out the bent portion and reinforcing it, but Van's recommended just replacing the spar.  That makes sense given the importance of the spar, and the fact that it's a relatively cheap part.  It's probably only one day of work to disassemble this one and rebuild and assemble the new one.  I will have to call and get it ordered.  Luckily, if timing works out, there is a builder from North of Seattle who is going down to Van's to pick up a kit in the next month, and he said he'd be happy to haul the spar back with him to save me the cost of shipping. 

Wing - Priming

The weather actually cooperated today!  While it was still pretty chilly for priming, the sun came and went enough to heat up the parts and make them dry relatively quickly.  The wind was a bit of an issue, but for hidden parts that will never see the light of day again, I really don't care if there's a random bug or layer of dust in the primer.  The hardest part of the whole process was judging how much primer to lay down.  With just natural light, it was extremely difficult to tell what had or hadn't been sprayed.

Before I actually started priming, I had to scuff and clean all of the parts.  For the ribs, the most annoying part of the process is getting the parts stickers off!  I had an old plastic scraper that worked really well, but it finally gave up and shattered.  A razor blade is too aggressive and scratches the aluminum, so I had another excuse to use my 3D printer!  For things like this, there's no need to actually design it in CAD.  I just found a scraper on thingiverse.com, and an hour later I had a finished product.  3D printing still amazes me.

 

At the end of the day I had prepped and primed the 8 skins, the two leading edges, the 14 leading edge ribs, stringers, wing walk doublers, and a bunch of other random parts.  It was a long day!  

Right Wing - Tedious Stuff

It looks like I might have a window in the weather to prime parts tomorrow.  It'll still be 20 degrees below the optimal temperature, but I think if it's above 50 I can make it work.  I really don't like spraying the primer in the closed garage because the primer overspray gets everywhere (it's dry by the time it lands, so it's just dust, but still), so fingers crossed the wind stays calm tomorrow and I can do it outside.  Today I spent most of the day doing as much prep as I could for mass priming.  First things first though - I received a new inboard leading edge rib today, so fluted it, fit it, drilled it, etc.

The only other actual construction thing I did today was to fit the fuel filler flange and fuel drain to the tank.  Then I settled in for hours and hours of hole and edge deburring.  The left wing skins are completely deburred on the inside and outside, but since I want to be ready to prime virtually everything tomorrow if possible, I'm just deburring the edges and holes on the internal surfaces of the right wing parts.  Once I prime everything, I can then go back and deburr the outside surfaces and holes.  It doesn't really matter when it's all done, as long as it gets done.  This just sped up the process enough for me to be ready for tomorrow.  The only skin I didn't get done today was the bottom outboard skin.  My handy little electric screw driver battery gave up the ghost.  I'll finish that skin in the morning.

For priming tomorrow, I'm going to scuff and clean, but I'm not going to dimple before I prime. Dimpling the skins after scuffing would add tons of time and there's no way I'd get through more than a couple of skins during the day.  Instead I'll scuff and clean, then prime, and once the primer is dry and hard after a few days, I'll dimple.