Polishing Aluminium

James wrote:

> Back when I was at school, I made a sand-cast turned aluminum blob for
> putting things in. To polish it, I used cloth polisher, and this brick
> colourd hard wax block type stuff. This was put on, and the metal
> polished whith it. What is this stuff, and where can I get it from!!!

Red rouge, basically rust suspended in some kind of paste, I suspect it a some sort of soap. Sears, Home Depot and most any tool store sell it. I bought a pack of 4 bricks, Black Emery (Silicon Carbide), Brown Tripoli (?), White Diamond (Aluminum Oxide) and Red Rouge (Ferous Oxide), for under $10. The Black Emery is the coarsest, Red Rouge is the finest. I have also seen these compound sold in individual peel away tubes. Red Rouge is used to put the final polish on precision optics.

For aluminum, the package recommends using only the Brown Tripoly and the White Diamond. The package recommends Red Rouge for Brass, Copper, Gold, Pewter, Sterling or Silver Plate, Nickel or Chrome Plate, Brass or Copper Plate, Stainless Steel and Thermosetting Plastics. Since Red Rouge is a form of rust I personally would not recommend using it on steel.

Peter Thomas

Follow-up:

Date: Sat, 2 May 1998 22:13:33 -0700 (PDT)
From: Malcolm Walker
Subject: Re: Polishing Metal

On Sat, 2 May 1998, Peter J. Thomas wrote:

> Plate, Stainless Steel and Thermosetting Plastics. Since Red Rouge is a
> form of rust I personally would not recommend using it on steel.

For steel a good fine polish is Chromium Dioxide. It's green. In a pinch you can use green oil paint (make sure it has CrO2 in it...) - won't cut as fast as polish compound but will still make stuff shiny.

I've only used CrO2 for putting a *super* sharp edge on a wood chisel. Apparently it does a good job of rust removal on flat steel. I wouldn't use it on aluminum though, it cuts too fast for soft metals.

-Malcolm