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Old 12-31-2012, 06:59 AM   #6298
Gnarly Adventurer
Joined: Nov 2010
Location: Thailand
Oddometer: 118
Plastic cleanup

Let me start with an apology: I didn't take pics of this project, and they probably would have helped.

Here's the deal: my sidecovers (yellow) were pretty oxidized, and had a few greasy fingerprints that I just couldn't buff out. A high-pressure washer applied by one of the Thai terrorists at the car/bike wash had completely obliterated the '200' stickers on the covers, and left gummy outlines where they had once been. This was not acceptable.

I tried every kind of vinyl cleaner that I could de-cypher the label of at my local Thai car accessories vendor, but nothing helped. I decided that abrasives were needed...

Rubbing compound? Nope. Petroleum seemed to have seeped deeper into the plastic than I could reach with liquids or pastes.

So, I grabbed a scouring pad from my wife's kitchen, and went to work. It was a bit too coarse, and left some pretty big gouges until I realized that I didn't have to press too hard. It was the type that looks like drill shaving curly-cues all tangled up in a ball. Faster motion, lighter pressure was pretty effective.

Turns out that where the decals were, there is a raised rectangular pad on the cover, presumably to highlight the position of the decal. I aimed to preserve this detail, while making sure to clean away the crud that built up around the edges of it.

After cleaning all the discoloration of the greasy fingerprints, I could see that the whole panel was oxidized, so I just continued the scrubbing process all over the panels, until they were uniformly clean (and, unfortunately, uniformly dull).

Next, I grabbed a washing tub from my wife's laundry room ("just for a while, Hun..."), and a few sheets of wet-or-dry sandpaper, starting with 600 grit, and including some 1200 and 2000. I filled the tub an inch or so deep, and started sanding with the 600.

First thing I noticed that, on the back of the muffler side, the heat shield was coming off, so I helped it, and set it in the sun to dry. I also popped out the rubber bumper from that side.

Then I wet sanded. And sanded. Changed to 1200, and sanded. Changed to 2000 and sanded some more.

After a few passes with 2000, it was pretty smooth, although kind of dull.

Now, some people might have got a buffing wheel at that point, and attacked it with rubbing compound. But I remembered making plexiglas tiny surfboard keyrings in high school, and - here it comes - fire-polishing them!

So, I got a big oxy-acetylene torch...NO I DIDN'T.

I got out my heat gun (like a big, very hot, blow dryer), and tried an experiment! I switched it on high (probably, you could do this with YOUR wife's hair dryer - but you didn't hear it from me), and aimed it at the needed-to-be-smooth plastic surface, taking care to keep it moving side to side, never in one spot too long. I could hold it so there was a bit of light reflecting of the area I was heating, and after a few seconds, a very shiny, almost molten patch appeared! I was careful to 'walk' this patch across the face of the cover, all the time keeping the gun moving, and pretty soon, I had melted the surface of the whole cover at least once, and let is cool.

It was pretty shiny! Not perfect, but MUCH better than just after sanding it. I tried going over it once again, but it never really got much shinier. So, I got out some cleaner wax (the one-step clean and wax type), and buffed it up by hand, and damn if it didn't look pretty good!

So, now my side covers are clean (but naked, no '200' stickers), and look better than the rest of the plastic on the bike.

I took some yellow contact cement, and glued the newly dried heat shield back onto the exhaust-side cover, and re-installed the bumper.

Finally, if (when) I get around to doing the rest of the plastic, I will start with steel wool, rather than the aggressive pot-scrubber I used. It's hard to find here (I did look for some before I started), but I think it would have made it less work. I *may* try to borrow a buffer and use some rubbing compound for the whole process (or only the last part), but the oxide was unusually tough, and I think I'll need the more aggressive abrasive to at least get through that part.

I think this process would work well with any color, but always try it on a hidden piece before you commit to the whole project. Dark colors (blue?) might be more difficult/less forgiving of less than perfect smoothness.

Heat guns can be bought for as little as $30 here; probably the same in the US, but a cheap hair dryer can be used for this (and shrinking heat-shrink tubing for wiring jobs). You can increase the temperature of the hair dryers by blocking the air inlet slightly (you'll see the heating coils get brighter), but don't overdo it.

A good way to spend a rainy Bangkok afternoon...have fun!
Sateev is offline   Reply With Quote