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Stewart, I can't provide any advice on fitting the cap strip, but I recently rebuilt the wings on my Alon, including removing and reinstalling the wing attach fittings (or hinges). I put the original 5/16ths rivets back in using a hydraulic press that I designed and had built. After disassembling the wings, I looked into using bolts to replace the 5/16ths rivets, but decided not to pursue it. The reason that I decided against the bolts (aside from the hassles of getting the paperwork approved) is that the factory drilled holes that the bolts go through in the wing attach fittings, spar cap strip, aluminum spacer blocks, and spar web, are not all perfectly in alignment with each other, and they are slightly different diameters. I had assumed that the factory would have drilled all of these parts as an assembly, but they didn't. They were all drilled at different times and then put together. This is evident not only from looking at the alignment of the holes when you take a rivet out, but also from the fact that the aluminum spacer blocks had primer in the bore of the holes, while the other parts didn't. I made up a test assembly with various sized holes to simulate the spar assembly, squeezed the rivets in it with the press, and had the machine shop slice through the part and polish the cross section so I could see the fit of the expanded rivets in the holes. The rivets expanded and filled the irregularities perfectly in even the worst aligned holes. Bolts won't do that. If you reamed the holes as an assembly, and then put in bolts, you would have to use bolts that were a "push fit" in the reamed holes. The problem with that idea is that you will end up reaming out quite a bit of metal, and you won't be able to buy bolts of the proper diameter. Have you already removed the 5/16ths inch diameter rivets? If so, how did you go about doing that? I removed mine without any problem, but I wasted an old junk wing figuring out a good method to do it without ruining the spar cap strips and attach fittings. They are not real easy to take out. That was probably the hardest part of the whole job. BTW, the reason I rebuilt my wings was due to a distinct popping noise that I could hear when I shoved upward or downward on the wing tip. (No, you couldn't hear anything in flight.) The noise was such that it would pop once when you pushed up, and then you couldn't make it pop again unless you pushed down on the wing tip, at which time it would pop again. After endless hours of hunting for the source of the noise with three different mechanics, we finally determined that the wing spar assembly (capstrips and web) was moving slightly inside the wing attach fittings and spacer blocks. This movement was so slight that it was barely perceptible unless you put you fingertip at the junction of the cap strip and the spacer blocks, and had someone shove the wing tip up and down. The movement was probably less than .001 inch. Because we weren't sure why there was movement there, I decided to take the wings apart and inspect everything. I found out that the rivet holes in the spar cap strips and spar web were slightly larger than the holes in the wing attach fittings. My theory is that because only the cap strips and spar web run the length of the wing (and therefore are subject to more load than the relatively short fittings and spacer blocks), and due to the sloppy manufacturing tolerances of the holes, the flexing of the wing caused the spar cap strips and web to start moving slightly and wearing on the rivets. Some of the rivets had signs of wear on them in the area where the cap strips and web were in contact with them. After definitely determining the cause of the noise, and seeing the inside of the spar attach area, I am convinced that the problem could have been safely ignored for another 30 years. (My A&P mechanic said that it was nothing to worry about even before we took it apart, but when I flew it in some turbulence, I wasn't comfortable with knowing the wings were moving.) But there was no way to know for sure what the problem was without taking it all apart. At least now my wings are perfectly clean, acid etched, alodined, and epoxy primed inside, with all new skins, new rivets, new wiring, etc, etc. And, ... that popping noise is gone. Sorry to get so long winded. Let me know if I can be of any help. Wayne DelRossi Alon N5618F ==^================================================================ This email was sent to: [EMAIL PROTECTED] EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Sid.bAhN69 Or send an email to: [EMAIL PROTECTED] T O P I C A -- Register now to manage your mail! http://www.topica.com/partner/tag02/register ==^================================================================
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