Preping the fuel tanks to close - 3.5 hours

Its time to start closing up the fuel tanks. I've been dreading this a bit since i'm not a fan of proseal or  MEK. I needed to prep the rear baffle of the fuel tanks so I went to work with my nylon brush and scored the mating surfaces of both baffles.

Next I cleaned the tank to get it ready.

After giving some thought to the process. I felt it wise to clean the primer off the z-brackets to allow a good clean surface for the MEK to adhere to. Also made sure that the holes where nicely deburred.

Closed the flaps and started closing the ailerons - 4 hours

Eager to get things finished now that the pre-close is complete. I started closing up the flaps as I thought they would be the easiest. 

Of course they go together fairly quick, there is still a bit of tricky off angle riveting to do. Fortunately nothing really flexes to the standard riveting with a bucking bar works well. You just need to make sure the bar angle is set up properly.

Once I had the flaps buttoned up, I didn't want to stop so I started in on the aileron. Following the procedure in the manual I riveted the leading edge skin to the to the nose rivets. Then I weighted the aileron down on a very flat surface. I started with the pull rivets on the leading edge/counterbalance pipe. One of the tricks I use is to poke electrical tape onto the pulled rivet mandrel. That way when the rivet is pulled, when the mandrel snaps, the work piece is protected reducing the chance of scratches from the mandrel.


I staggered the installation of the pull rivets similar to the method used for the rudder trailing edge in efforts to get a straight aileron. The result is an extremely straight piece!!!

Pre-close inspection for the wings is complete

The pre-close inspection by the MD-RA inspector is complete. Nothing to do other than close-up. 
 

Rivited the 2nd left aileron skin to the spar - 3 hours

In order to attempt the riveting of the 2nd aileron skin i decided the best course of action was to call in some experienced help. I asked my friend Mike who is an AME to come give me a hand bucking the rivets. Sure enough, we ran into the issue of the rivets wanting to slump straight away. We drilled a couple out and tried again. Yup, they have a tenancy to want to slump. We double checked everything we could, the bucking bar is nice and straight but just not bucking good.

We then decided to brace the aileron with a framework to help alleviate and bending while riveting. We suspect that the forces placed on the aileron while trying to buck is bending/tipping the aileron enough to affect how straight the rivet is with the bucking bar. 

The frame work certainly helps a lot, rivets went together nice and straight. However we found towards the middle of the aileron the there is a tendency again for the rivets to slump. So, we decided to back rivet these with a C-frame rivet set and mike on the bucking bar on the exposed side. We did a partial set of the rivet and then switched back to the bucking bar inside and rivet gun outside with the flush set to complete the rivet buck. Worked like a charm. I am very satisfied with the result. Very good rivets.

I am all ready for pre-close inspection

Started riveting the 2nd left aileron spar - 1.5 hours

I riveted the reinforcement plates to the main spar and then cleco'd the aileron assembly together. I then began to rivet the end/nose ribs to the main spar.

Drilled the 2nd left aileron counterbalance pipe - 3.5 hours

Next order of business is to drill the aileron counterbalance pipe. Truth be told, this is not a process that I enjoy. It takes a bit of time and you pretty much need to do the drilling by hand. I cleco'd the assembly together and started drilling the holes with #40 drill bit. I inserted a #40 cleco in each hole as I drilled. Then, I went back and drilled out all the holes with #30.

Once all the drilling was done, I then set up the drill press and countersink the pipe to accept the pull rivets. One item that I did differently this time round was to dimple the leading edge skin of the aileron by hand with a mallet rather than using the rivet gun on light pressure. One or two light taps with the mallet is all that was needed to provide a crisp dimple.


I then prep'd and primed all the remaining pieces and began riveting the nose rib to the counterbalance pipe.

Match drilled 2nd left aileron - 5 hours

Managed to put in a big day (well sort of) on the build. I finished up the back riveting in short order.


I had picked up a material yesterday to build the bending brake and the wood dowel so I could bend the skins. I was sure this time to slightly notch the wood dowel to allow the skin to be bent without the stiffeners digging into the dowel preventing a nice tight bend.


Once the skin was bent. I began the task of match drilling all the aileron spar components. Everything went well, same as the first one.