Thursday, April 11, 2013

Removing Paint From A Bicycle Fender And Cleaning a Bicycle Wheel

Front Wheel


I spent last weekend working on the Hercules. Saturday was devoted to cleaning up the front wheel. The original rim was plated with a black stripe down the center. Unfortunately, paint over plating does not tend to last very well. Add to that the fact that it had been housepainted, and the center stripe was pretty much unable to be saved. Fortunately, the plating underneath where the paint was is still in good shape. The plating where the brake pads rub is long gone, but then that's honest wear and there's no shame in it. The sides are a bit pitted. The inside of the rim had surface rust but nothing overly serious.


 The hub has its original metal oil filler still but has lost a bit of plating. That said, it has aged relatively well and I don't see the need to do more than a basic cleaning on the hub shell. I will be re-greasing the bearings and races once I decide whether I will be re-spoking the rim.

 Method: Cleaning a Bicycle Wheel

I used a basic method on the wheel rim: once I knew the paint was just going to flake off, I went for a Dremel brush and brushed it all off. It basically just came off in flakes. There's a reason you don't see a lot of makers paint large areas over plating- the paint just doesn't adhere well it seems. I took the brush around and around until it was down to the plating and metal. For the spokes, I used WD40 and bronze wool. The galvanizing is gone. There is moderate pitting on the spokes, which is never a good thing. I may re-spoke the wheel, but then again it has all its original spokes and is in tension still. Perhaps I will try to save it. On the hub shell, I used a combination of WD40 and bronze wool. On tough spots, I reached in with the Dremel wire brush and WD40.

 Cleaning A Bicycle Fender

The rear fender was covered in a layer of primer, then home spray paint, then house paint on top of that. To make it worse, then another layer of white house paint was used for the white tip. Removing the fender brace bracket showed the original paint was plain black.

Stripping:

Stripping paint is not easy if you want to preserve the original layer at the bottom. Earlier, I discussed stripping to bare metal for a re-paint. This time, the job is more delicate. I did this the same way as the front fender. I rubbed a few different paint stripping chemicals to see what would work. Acetone was the pick. Second, I rubbed the acetone until it started pulling up and softening the house paint. I then used a Dremel felt sanding drum to "rough and dig" up the house paint and layer of spray paint underneath. This took a careful touch and produced a nasty, gooey, gray paste finish. This is the phase where you begin to wonder if you're doing it correctly. It looks like grey clay crap. But the payoff comes with the final rub of Acetone. Using a careful touch and persistence, the Acetone pulled up the gooey, gray crap and left the original black paint. The finish was compromised to bare metal in some spots, and the area that had been painted over with the white had lost its original finish. It is very important that you first weed through the layers of over paint to see what you have. In this case I knew layer 1 was house paint, layer 2 was spray paint, layer 3 was spray primer and layer 4 was original. Know how many layers to pull back, and what color is important. It is also very important to find a chemical that will hit the over paint but leave the original finish.

Polishing:


Once the over paint was gone, it was time to see what the original paint could do. I took out the Scratch Doctor polish and went to work. The original black shined up for the most part. The over paint primer had made a few stains, and the area hit by the white spray paint was down to bare metal. After polishing I hit any surface rust with a Dremel brush and WD40. Last night, I came back and cleaned the inside of the fender well with soap, water, a Dremel brush, and WD 40. I then used a black paint to coat the inside of the well to prevent rust. Tonight, I returned and began to patch up the finish on the outside of the fender. I used a basic, thinned black enamel. Using a brush I filled in the holes and using a black paint/thinner impregnated rag, I rubbed over rough spots and the bare metal of the lower portion. At right you can somewhat see the results. The day was done and I was stuck with my garage lights for this picture, but it gives you the idea of the condition: decent original paint overall with some patches of touch-up.  

 

Where Next?

At this point, I have to get to work on the back wheel and clean up the rim. First, I need to decide whether I am keeping the original spokes or replacing them all. Two spokes on the back wheel are replacements already, but all the other spokes on the bike are original. The fronts have some pitting. The backs look a bit better, but I still need to clean them.




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