More Preparing the Left leading edge - 3 hours

I had decided to change the order of process with priming. Do you prime and then dimple, or dimple then prime? Well with the 2 part epoxy that I had originally started out with, priming then dimpling worked just fine. But now that I have switched to self etching primer is another story. Seems that dimpling after priming has a tenancy to scuff the primer exposing the metal in some areas.

So from now on with the self etching primer I will prime after dimpling and see how that goes. I wasted no time setting up. I scuffed up the areas that I want to prime, then I started dimpling.
 
Once I was done the dimpling I went back over everything with more maroon scotchbrite to ensure good adhesion. A round of degreaser and remover, a round of MEK, then a coat of primer.

Once that was done, now came the tedious task of deburring the nose ribs. I found that it is a bit tricky to deburr some of the holes as some burrs are stubborn to get out, and access to the inside holes is not easy. A dremmel tool with the scotchbrite wheel is your friend in this case. I also filed and smoothed out the nose ribs really well. Lots of work, but worth it. I finished the rib prep by dimpling.

Preparing the Left leading edge - 2.5 hours

Not much in the way of pictures. I match drilled the left leading edge assembly and removed the ribs. I then deburred the skin. All I need to do is prep and prime mating surfaces but I want to have a little more time to start down that road.

So not wanting to dive into a whole load of work so late, I riveted on the K1100-08 nutplates to the splice plates. Always a good feeling to rivet! Means stuff is ready to go together.

Need a break from the fuel tanks, To the leading edge - 2 hours

Just need a break from the tanks. I just feel like I need to make bigger steps so I have decided to move over to the leading edge. I'll finish the stall warn device and leading edges and rivet them up. Just good to get on to something different.

I had picked up some aluma-brite 218 on the advice of another builder and I've been dying to give it a try, So after deburring, scuffing, and dimpling I set up and applied it to the stall warning assembly and the splice plates. It does a pretty good job. As soon as I wash it off it is apparent that it works. Water sticks well to the cleaned surface...very nice.

I then primed the pieces. I choose to use the 2-part epoxy as it stands up to abuse better than the self etching stuff, so I used it on these parts. (I will also use it on the leading edge nose)

Fuel tank trap door - 2.5 hours

I managed to pick-up the proper hinge (MS20257-3) so I moved back onto the fuel tanks. Figuring out how to best set up the trap door took an amount of head scratching.  The trick is that you can't really follow the plans for the upper hinge as the depressed ring pattern on the rib prevents placing a rivet where needed. Looking at other build sites, one method employed is to leave the top hinge longer to bridge the gap. The next challenge is to layout the hinge so that there is good support of the hinge loops. In my opinion it is much better to have 2 loops per side.

Lots of sketching, checking, moving, re checking. It's not so straight forward.

This is the final version of the layout I chose

I then drilled to #40 and then countersunk the trap plate for a NAS oops rivet. My opinion is that the NAS rivet should be alright here as this is not a part that is subjected to stresses. However, since I only have two rivets to hold the top hinge I have decided to countersink the thicker hinge material for an AN426AD3 rivet.

Most important I thought in the process was to install a spacer under the top hinge the same thickness of the trap plate so that is sits flat against the rib.


Mental note.....MEK does not take off sharpie marker on hinge material!!! Nothing seems to.
I even tried buffing and sanding it off...GRRRR!

To proseal or not to proseal

So the big question of the day is how much of the NAS1473-A08 nutplates and stiffner ring assembly should I proseal. The plans state that I don't have to proseal any of it. (Under 'Assembling the Fuel Tanks' 4th paragraph undet the heading 'Final preparations'). I notice though that many build logs use proseal and do everything.

The manual states that the gasket under the access plate will seal the rivets so there is no need to set them with sealant.

This makes me a bit uneasy. My tooling holes are awefully close to the edge of my stiffener ring/access cover. I plan to use seal-tite in lieu of the cork gasket...but I do want to run some proseal  between the rib and ring to make sure that the tooling hole is covered.

Question is....Do i need to proseal anything else?

Stall Warn System - 1.5 hours

I'm waiting on my hinge to finish the fuel tank trap door, so I decided to move back onto the stall warn system now that I have all the needed odd drill bit sizes.

I opened up the holes in the leading edge to #10 and then used a dremel with cutting disk to carefully cut the slot. Then I used a dremel with 600 grit on a mandrel to polish the opening.
 

Then I match drilled the mounting holes and countersunk the holes. I deburred the leading edge bracket and dimpled the holes. Took a little time to fiddle with the countersinks to get them right. All that I need to do is prime the parts and start assembling.

Little bit of riveting on the tank mods - 2.5 hours

I cleaned the #2 ribs and the hole blanks really well with MEK. I was careful to ensure correct orientations of the blanks (always a pain when you just wanna get it done). I decided to dimple the parts and backrivet.

Then next I needed to countersink Rib #1 for the access plate nut plates. I decided to go oops rivets for those and not dimple.

I'm fairly certain that I don't need to proseal these when attaching the nutplates. The plans say don't do it. I am using the NAS1473-A08 nutplates...Seems like everyone seals them with proseal.....but I'm thinking I don't have to. Nobody seals the standard nutplate method. The seal around the access plate takes care of any potential leaks. Hmmm. Need to read up on this.

I machined countersunk the anti-hangup bracket and backriveted the assembly with AN426AD3 rivets. I will wait until I get into proseal before I rivet it to the access plate.

All that's left to do is fit up the inner anti-holdup bracket, the fuel vent line and locate the fuel sender on the baffle plate. Then I am ready to dive into proseal!