As the title suggests, I opted to implement this SB since I still had easy access to with the bottom skins off on the left wing and bot the top AND bottom skins off on the right wing. The fix was pretty straightforward, with the most difficult part being removing the old rivets once the heads were popped off. I'll proably end up having two different variation of this SB in regards to the bottome 470 rivets. After completing the left bracket I've read from numerous builders posts that the rond heads interfere with aileron clearance. Van's solution was to either file the aileron back, add extra washers to move the aileron outboard, or drill out and replace the offending rivets with counter sunk rivets. As of this writing I have yet to assemble the bracket for the right side, but when I do I will most likely go ahead and counter sink the bottom rivets on the bracket. As far as the left side goes, I'll just wait and see how it goes with installation. I've read mixed results about the success in adding washers for spacing.
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Much like the wing ribs, there was not a whole lot to this section. As the title of this post aludes to, little did I know that the aileron brackets that I installed, would have to come back off due to the SB issued in May. During the process of inspecting each rivet for blue fuel dye stains, my heart sank when I found a rivet hole without a rivet. In the photo above, I have an alignment punch stabbed through the proseal filled hole. After much thought, and consultation from VAF, I decided to countersink the hole to accept a countersunk closed end blind rivet. The pictures below show before and after countersinking. For good measure, I was able to contort a piece of AL to slather a blob of sealant on the shop head of the rivet. The good news is that even if it didn't seal completely, the location of the rivet makes it highly unlikely to leak.
I leak tested my first tank about a week after completion (November) using the schrader valve and balloon method. After a few attempts at getting the balloon to seal on the vent line, I sprayed soapy water liberally over every rivet. Success!! Leak Free!! Fuel Tank Complete!! Not so fast..... My second tank was completed not long after the first but for whatever reason had not been leak tested. I got busy with wings and basically kept putting it off. One day I came across a thread on VAF regarding the difference in flaring tools, automotive vs aircraft. I decided to read a little deeper since I bought my flaring tool (used to fab the vent lines) from autozone. I then went down a whole different rabbit hole on what happens if the mismatched tubing flare and AN fitting are mated since one is 45 degrees and the other is 37 degrees. A potential leak path between the internal tank bulk head fitting and fuel vent line could be a problem, causing a constantly dripping fuel vent to venting and fuel feed issues. I decided I needed to halt all work on the wings and circle back to my tanks and see if I had a leak. I used about 6-7 gallons of 100LL to test the tank. I placed the tank in its cradle and laid it down, filled with gas, for a few days. There was no evidence of leaking any where. I didn't get any photos of what I'm about to describe but next, I propped up the outboard end of the tank so that the entire inboard baffle including the vent fitting would be covered in fuel. Once again no leaks leaks were found, but that doesn't mean that I'm free and clear. Once the plane is flying, vibrations or what not could case the fitting to begin leaking at which point I'll have to decide what to do. The proper fix is to replace the vent line with a properly flared fitting. However, the only access to the inside of the tank without cutting a hole is through the fuel float hole.
Before starting the wing ribs, I'd heard the horror stories about the monotony of this section. I can report that although monotonous, it wasn't all that bad. Not too many pictures to post in this section. After completing the tanks, a section without proseal was a welcome relief. The main spar section basically has you use the main spar as a drill guide for the stiffeners that will be used in later sections. Aside from that, just a WHOLE lot of of countersinking and nut plates. I put a piece of tape over the crack on the forward side of the spar to minimize the shavings that would get stuck as a result of all the counter sinking. Next, I shot some primer on the top and bottom flanges and installed the autopilot servo mounting bracket.
While installing the fuel pick up assembly/finger strainer, I couldn't figure out why I had so many threads left outside the hole after tightening the assembly. I posted the question on VAF here and felt like an idiot afterwards. I'll just chalk this one up to a brain fart. The picture below is what the inboard side of the fuel pickup assembly.
What better to do on a hot muggy, rainy, November day? Why work on an airplane of course. Louie was not impressed with the rain and kept a safe distance from the wet stuff. All I really managed to accomplish today was build up some frustration while I worked on the fuel floats. However, there were two valuable lessons learned:
1) As the pictures shows, there are two different fuel float part numbers (L & R). I apparently glossed over the plans and failed to notice two different part numbers on the box. I finally realized something was wrong when I just couldn't get the holes on the sending unit and the inboard baffle to line up. 2) If after bending the float wire the float just isn't quite right and touches either top or bottom of the skin, cutting it shorter does not work. These wires are pretty stiff, and once they are bent at a 90 degree angle it is difficult to unbend or straighten them. So Van's got another $5 from me and sent me a new wire. In the meantime I used the wire for the other sending unit (which I managed to not screw up). As with most builders, I didn't get too many pictures of proseal in action. Before I got to the fun stuff there were are couple of tooling holes in the end ribs that needed to be filled with #6 rivets. The plans suggested mounting the rivet gun in the C-Frame to buck these. I used that method for the first few, but I overlooked the other end ribs and installed them without first filling the holes. I bucked these using my 5lb back rivet bar with no problems. After seemingly endless prep work on the skins and stiffeners I finally had my first proseal session. It was messy and nasty, but I knew that going in. Many people apply the proseal and 100% cleco and wait for the proseal to cure before riveting. Again, I decided to stick with Van's and rivet them wet. It was not not fun, but mission accomplished.
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