Tonight I finished the two z-brackets that had to be re-done and installed the nut plates that I was missing. 

The spar was fairly easy to countersink for the nut plate rivets, however the outboard rivets have to be done without a countersink cage.  Use a sloooow drill and its a piece of cake.

Unfortunately I cannot say the same thing for these rivets.  I had a heck of a time getting these rivets done and it took me way longer than I wanted.

I also drilled and affixed the nut plates to the capacitive fuel sender plates. 

Finally, a day in the shop where I left feeling like things are moving along and a lot was accomplished and I was much better about taking pictures today.

Today I started by machine countersinking the tank skins to fit the baffles.  These need to be countersunk instead of dimpled in order to allow the baffle to be easily installed and sealed.  It takes time to countersink all of those holes, as its an easy way to really mess up the skin.  

Here’s a good close up of the countersinking in progress. 

After machine countersinking was done, I disassembled the tanks and labeled all the parts.  I then turned my attention to the tank attachment angles and reinforcement plates.  I realized when I looked at the plans, that I had forgotten to trim off the excess (more than 2″) on the reinforcement plates, so that was the first task.

Next, I clamped the angles in place and drilled the three parts for rivets. 

Now after doing this,  I’m pretty sure the reinforcement angle should be higher up to help seal the tank, but its too late now, so I’ll have to cross that bridge when I come to it.  Worst case scenario, I have plenty of scrap and can fabricate a replacement quickly. 

Time to move on to the capacitance fuel sensor I purchased.  Each tank has two plates that need to be installed and isolated from the structure.  I match drilled all four plates. 

I made the stiffeners ahead of time, but skipped final drilling them when the instructions called for it.  This was a good call.  I was able to trim the fuel sensor plates to fit the stiffeners at the same time as I did the final drilling.  Saved me a step or two. There is still a lot to do for the tanks before I can start sealing them up.  Next time I will try to compete the fuel sensor and access plates. As a side note, I bought a fly cutter on Amazon for $10.99.  It arrived today and here is a picture.  It can cut holes with diameters up to 6 inches.

This has been a frustrating weekend for the project.  As I noted previously, I ran out of K1000-03 nut-plates, so I was not able to finish installing the z-brackets.  I put out a call to local builders, and still no luck!  I guess Van’s doesn’t include many extra K1000-03 nut-plates with their kits. In the mean time I decided to start work on the access plate since it was easily accessible and the next logical step.  Unfortunately, neither Sears or Lowes had a fly cutter!  Foiled again. No more.  This time I went on Amazon and ordered a fly cutter, and made a promise to myself… I’m never shopping in a retail store again! By this point, Saturday was basically shot.  What I decided to do was install all the brackets and ensure the bolts properly seated in the nut-plates.  A few needed very minor adjustments, but I was able to install all the completed ones.

Thats when I realized I could at least drill out the z-brackets.  I fabricated the new inboard brackets, and just bolted them in place and then using the Checkoway Method, I drilled the baffle to the brackets. After I got that done, I final drilled both tanks in their entirety. The stiffeners are already complete as is the attachment angle.  I need to do the capacitive fuel sensors, fuel drains, and fuel caps.  Then its deburr, dimple, and seal!  School starts back up next week, so I’m really hoping I can get a lot done this week.

In an earlier post I referenced Jason Beaver’s RV-7 build for a thorough walk through on the Checkoway Method. I did not take many pictures, nor do I have the energy to type up the full procedure as he has done, but I will provide a synopsis.  Definitely use this method and do not follow Van’s instructions.

Checkoway Method: Temporarily install and align the fully clecoed tanks in order to ensure proper alignment.  By removing the outboard leading edge you can drill the innermost and outermost brackets and cleco in place.  This ensures that the baffle is perfectly aligned.  Remove the skin, and interior ribs so that only the baffle and outter ribs remain.  Now you can access the entire baffle for match drilling.

Here are some pictures mostly from when I finished for the evening. 

Here is the middle of the Checkoway Method.  By drilling the other brackets, and then removing the rest of the structure you can easily access the middle of the baffle.  Just remember that the ribs still need to be final drilled when you put it all back together.

A few pics of the shop at the conclusion of the session.