My experience getting the right level of polish and clearcoat. Mark clued me into some of this!
The short of it is that Honda did not polish these engine covers to chrome-like shine. Over polishing them is, therefore, to be avoided!
My technique:
1. Remove the old clearcoat with a paint remover. I use Aircraft paint remover. Just be sure to not let it sit on the aluminum too long; it can stain aluminum if left for an hour or more.
2. Wetsand out scratches with 400.
3. Once scratches are out, sand the entire part in the correct direction. Keep it in one direction. Cross-sanding will show up in the light!
4. Progress down to 1000 grit paper. All wetsanding of course.
5. Polish the part. No need to get it to a perfect mirror shine. Again, polish in the same direction that you sanded.
6. Here's the strange part that Mark clued me in to: go back and scratch the polished surface with grey scrotchbrite. This is seems crazy, but it will look great. Make sure you have gone over it a few times so the scotchbrite scratches are even.
7. Go over it again with white scotchbrite to smooth everything out just a bit. You should now have a part that shows the "grain" of your sanding, polishing and scotchbriting in the same light.
8. Clean the part with wax and grease remover. Super important to get the surface as clean as possible before paint!
9. Paint the black behind the honda logo if you are working on the alternator cover. Make sure you use high-heat engine paint. I use duplicolor engine paint and have been pleased.
10. Not its time to paint the clear coat. This is your final chance to get wax, grease, fingerprints and more off the metal! Paint in the shade so it has time to even out before drying and give it three medium coats with 5 to 10 minutes pauses between coats. The old paint guys always tell me to make the last coat look like one big drip! Avoid real drips, but the point is to not go too light or you will get a satin-look to the clear coat instead of a reflective finish.
That should do it!
The result:
Ready to put in the frame. by
samuelmroberts, on Flickr