Tuesday, October 6, 2009

Temporary Spoke Repairs

A friend, ZhiSheng, invited me on a bike tour of Taiwan in early 2008. They needed a fourth to share the hotel expenses. I was riding a Peugeot that I had purchased in College in probably 1970. I had taken a five day tour then so certainly the bike and I could do it again.

About fifty miles down the road I broke a couple of spokes. They weren’t just any old spokes; they were the spokes next to the gear sprocket (“freewheel”) on the back wheel. In order to replace these without removing the “freewheel”, ZhiSheng took a longer spoke, cut off the curved tip, bent it into a Z shape (two ninety degree bends) and slipped it into the hole next to the “freewheel”. ZhiSheng, I forgot to mention, has the local Giant bike shop in ChangJhih where I live during the school year.

The trick is to get the new spoke the proper length. The first bend on the new spoke must be at about the same distance from the thread end as the bend on the correct sized spoke. The second bend needs to give just enough room to go through the hub. The remaining distance needs to be short enough so the spoke will point in the correct direction, although it can bend sideways a little. See the photos.





The spoke does not pull out, as it is stiff enough to hold its shape under the tension. I was surprised, but we did it several times before the trip was over. As it turns out, the holes on the hub that the spokes went into were cracked and as I rode, they wore out any spoke we put into it. I finally got a new hub in Taipei and the problem was solved.

below is a picture of the tools I carry with me in my saddlebag.

Friday, October 2, 2009

The Shining

My friend, John Cowgil, has a Cessna 140 that is polished aluminum. That is to say, the fuselage is polished aluminum; the wings are fabric and silver coated. The fuselage, somewhat smaller than mine, shines like a mirror, and unfortunately, sets the standard at our airpark, A20. Thanks a lot, John.

Having purchased an unpainted (I say unpainted as it had not been polished in years) it was up to me to bring it up to the airport standard. When I purchased the airplane about three years ago, I spent about three weeks experimenting with different polishes and polishers in search of the magic potion that would bring my dull metal to a mirror finish with the least amount of work. I tried big orbital buffers and small orbital buffers. I tried about six different miracle polishes, all to no avail.

Finally I stumbled upon “Top of the Line”, a system using three different grits of polish and a sealant, along with a twin rotor buffer with three different types of pads. This provided the polishing goal, but nowhere near the “least amount of work”. At the end of my first foray into restoration of the shine, the plane showed a remarkable improvement, but when compared with John’s 140, it didn’t reach the bar. Thanks a lot, John.

This year, as I hadn’t sealed the aluminum in three years, the oxidation was starting to come back. Hsien-Ling and Johnny had to go back to Taiwan at the end of September so Johnny could start fourth grade but I had to stay an additional four weeks for work purposes. I took advantage of this to again attempt to bring my plane up to standards. It was a chore.

I remember in high school having a ten speed bicycle with aluminum handlebars. Occasionally I would have the handlebar tape removed and when I did my hands would turn black from the aluminum. In polishing the plane I not only tuned my hands black, but my entire body, and the entire hangar floor. I had a stack of 30 terry cloth towels that were blackened and rewashed each day, and the shower floor, well let’s just say I am lucky I cleaned it before I left for Taiwan.

I had come to the conclusion that the belly of the plane was a different kind of aluminum that wouldn’t polish up. Unfortunately, I found some Turtle Wax rubbing compound and a buffing pad for my sidewinder grinder. It polished up, and that meant that now I also had to polish the bottom.

Starting with the tail, I did one side in one day. Step pne was to use a wool pad with the coarsest grit, clean it off, then use a terry pad with the second coarsest grit, clean it off, followed by another terry pad application of the final polishing compound, and clean it off. Then with a sponge pad the polymer sealant is applied and buffed off. The hardest part is the cleaning and buffing between applications. The tail seemed fine until I went back over to John’s. Then I did it again.

Second in line was the trim around the windows and the top of the back of the cockpit. Third were the flaps and ailerons. It would have been nice if I could have removed them as they had areas that could not be reached. Now that I write this I realize that there is an area that is exposed when the flaps are down that was not even touched. Something for me to do in January I guess. Fourth was the bottom of the left wing. Here the oxidation was such that I could wipe it off with my fingers. The application worked great, the only problem was that I had to hold up the buffer against the wing, and it became annoyingly heavy. The wing was also not at the optimum height, too low at the root and too high at the tip. The process was the same, buff on with machine, buff off with a towel. Occasionally friends would stop by to see what I was doing and I have to say that the phrase “wax on wax off” got old real fast. Interestingly enough though, I have several friends who have offered to fly my plane while I am gone to keep the engine clear of rust, none of them offered to help polish.

After the first under wing I had discovered the possibility of polishing the belly so I went there next. At least under the plane I could lie on a creaper and hold the buffer on my stomach. The first pass with the sidewinder and the rubbing compound I did without the creaper and cleaned the floor with the back of my shirt and hair. As I did this I saw that I was running out of material and pads so did the first two passes on the belly and then the first pass on the underside of the right wing. With a delay of a day or two the additional material arrived and I was finally able to finish.

Two things would have made the exercise a lot easier: 1. If I could have removed the flaps and ailerons and polished them on a bench it would have been a lot easier and I would have been able to get the parts obscured by the wings; and 2. If I could have just turned the plane over just for a little while to polish the belly and the underside of the wings…..

All in all, it came out fairly well and I have already received good comments that almost make it worthwhile. Next time I will buy a painted plane.