Re: Polishing Aluminum
If you sand it you must sand it all. Left on its own for awhile it will develop a very thin but hard layer of oxide.
Sort of like the protection you get with anodize.
When you go to buff it the portion recently sanded will buff up like chrome but the older oxided area will resist polish until you wear it out and break through it.
We learned this the hard way when we machined wheels and let them sit for a few months. We had to spin them up on the lathe and go through the oxide with sandpaper then up through the grits before we were able to put a shine on them.
There are chemicals that will take the oxide off and leave the metal looking ugly until you polish it, just make sure you polish it immediately.
Also make sure that after you polish it that you wax it.
From: David Froble davef@... [canard-aviators]
To: Dick Finn
Cc: Canard Aviators Mailing List
Sent: Wed, Sep 17, 2014 10:48 am
Subject: Re: [c-a] Polishing Aluminum
If you sand aluminum, it will no longer have a smooth finish, if it ever
did have one. Been there, done that. Sand before anodizing, and it
really looks bad.
If you want to polish aluminum, you can buff or burnish it with a soft
Dick Finn COZY7971@... [canard-aviators] wrote:
> I'm having some trouble polishing my hinges for the nose access door.
> After building the hinges for the FHC I was inspired to do the same for
> the nose door. The hinges are completed and fitted so I had a go at
> polishing the aluminum much like I did with the hinges for the FHC.
> From the beginning a significant portion of the metal had a haze. I
> continued starting with 120 grit sandpaper and working up to 1000 grit
> (same as with the canopy hinges. The haze remained. I then tried to
> buff it out. Part of the metal now looks like chrome while the
> remainder still has the haze.
> This was a left over piece of 1/8" aluminum. It has to be from either
> AS&S or Wickes since that is the only place I've ever bought aluminum
> (in other words, its aircraft grade and not hardware store supplied.
> Does anyone have a suggestion?
David Froble Tel: 724-529-0450
Dave Froble Enterprises, Inc. E-Mail: davef@...
DFE Ultralights, Inc.
170 Grimplin Road
Vanderbilt, PA 15486