OK Tom, just for you and anyone else that didn't read my article in Stunt New a couple of year's ago. Here it is, pretty much verbatim.
"I decided to spend some time going through last years’ model and make some past due repairs and general maintenance. It’s a good thing I did! While cleaning and repairing dings, I had to remove the sealing tape on the control surfaces. Really, they should be replaced from time to time anyway. When I removed the tape from the outboard flap I discovered three hinges that had come loose from the wing. It’s hard to say how long they have been that way, but it looked like an accident waiting to happen. Repair in this case, is simplified by the fact all of my control surfaces are removable. I do it a little differently than most. I use two wires on each wing going from the middle of each wing toward the tip. My first effort a few years ago, I used the traditional method of one wire per wing starting at the wing tip and threading through each hinge. That’s fine except, if there is any misalignment it becomes difficult to thread a piece of .031” wire that is at least 25” long. Of course, perfect alignment cures that, but I find my way easier. Each wire is held in place bay a small piece of tubing recessed into the trailing edge.
As it turns out, it looks like I simple forgot to glue those three hinges during original assembly. No harm, no foul in this case because the sealing tape held. I glue hinges in with thin CA, a method I learned a few years ago form John Miller. First the hinge tabs need to be roughed up with sandpaper to give the glue some “bight”. Cut some heavy silkspan the same width as the tabs about two inches long. Fold the silkspan over the tab and push it into the hinge slots of the trailing edge of the wing. You will have pieces of silkspan sticking up on top and the bottom of the wing. Carefully apply a very small amount of thin CA to these pieces and will quickly wick into and attach the hinges permanently to the wing. Try it on a practice piece, you’ll find out that the hinge can’t be removed without taking wood with it. I have removed with “un-cure” before, but with a little care they will come out fine. Also, I should mention that it is a good idea to coat the barrel of the hinges with Vaseline or WD40. Again, if the hinges are sticky they can be freed up with CA debonder.
One other thing I do is drill out the hinges with a #60 (.040) drill and deburr all the edges after removing the existing pin. This may not be necessary but worth a try on a practice piece. It makes the hinges very free even after the sealing tape is applied and you will never notice the extra clearance in the fit. "
Note, if you are afraid of the CA method, use some other glue. The CA makes things really quick.
Topic: Hinges (Read 7409 times)
