Date:         Sun, 13 Mar 2005 10:59:37 -0800
Reply-To:     Alistair Bell <albell@UVIC.CA>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Alistair Bell <albell@UVIC.CA>
Subject:      Re: Brushed-metal finish on aluminum stock (NVC)
In-Reply-To:  <20050312030018.62573.qmail@web14625.mail.yahoo.com>
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Jeff,

Which method best? depends on the amount to do and the effect wanted. I
haven't tried to get the brushed finish you are looking for. I also
haven't tried a flap sander on a drill press, but i can see how that
could be set up with a fence and a nice feed rate to achieve what you
want.

As to grit size, well this is where surface prep is damn frustrating.
You probably have a couple of scratches deeper than the rest on your
bits of Al. You really have to use the coarsest grit to rub them out,
then progress up thru grades until you get the desired surface finish.
It seems that there is not substitute for manual labour and time in
these steps. If you don't believe me :) then head over to your local
metal polishing shop/outfit and ask about prices for various degrees of
finish, matt thru mirror.  It takes a skilled hand and patience to get
the best finish.

In other words, i can't give you a grit size recommendation. But you
probably will be starting and finishing with pretty coarse grits to
achieve the brushed look.


When you set up your jigs and workplace, be sure to keep it tidy and
clean. The Al will scratch so easily! And its a good idea when using
abrasives on metal to wear a mask and keep the dust way down, I doubt
you will be making enough Al dust for it to be an explosion hazard, but
it makes live so much nicer to have a vacuum hose right by the drill
press table (if using the flap wheel).

If i were you, I'd play around with some scrap, long bits mind you, and
try hand sanding first to see if you get  the finish you want. Hand
sanding might just be the best for a one-off.

Good luck!

Alistair



On 11-Mar-05, at 7:00 PM, Jeffrey Earl wrote:

> Alistair,
>
> Thanks for the advice! Of all the methods you've
> tried, which do you feel works the best? I want to
> make the long, linear striations commonly seen on SS.
>
> When using a random sander, what grade sandpaper do
> you recommend?
>
> Finally, why don't conventional laquers or clear
> sprays like Krylon or Rustoleum work on Al?
>
> Appreciate all your help. Thanks again!
>
> Jeff