Polishing Aluminum Parts

There are several trim parts made of aluminum.  These include the grille, hood bows, trunk and door trim.

These were all just polished natural aluminum, not treated or anodized in any way.

Of course, after 50 years of so, they get beat up, oxidized and in general, don't look good.  Polishing aluminum isn't difficult, just time consuming, though not as bad as polishing stainless steel.  To start, one has to remove the deep scratches using a file or sandpaper.  After that, I found that a palm sander with 220 grit paper worked well to clean the rest up.  I continued with 400 grit wet sanding.  The final two steps are buffing, first with a Tripoli cutting compound and finishing with Blizzard color compound.  The Caswell Plating website has an excellent PDF file on buffing and polishing.

Here are the hood bows after the first buffing.

The door scuff strips were pretty beat up and one had a bent area on one end.  I found that 1/2" copper water pipe had just the right OD to use as a form for fixing that end up.

   

These strips get a lot of abuse.  I might have them anodized after they have been polished.  Anodizing hardens the surface and prevents the natural oxidation of the aluminum that dulls the surface over time.

The piece that surrounds the trunk latch also gets dinged up quite a bit.  You can see some big ones on the edge.

It took a little tapping out, a lot of filing and sanding, but this is what it looks like after 220 grit sanding.  No more dings in the edge.

Then I did a sanding with 400 grit wet and a quick polish.  I realized that I need to go back and sand more with the 400 grit before going any further.