"Andy Evans" wrote in message
ups.com...
Like may people I use aluminium in equipment cases - in my case for top
plates for valve preamps and amps. I use 4mm alu, which Fays Metals in
Acton London supply and cut to size. It's not great looking in its raw
state, but all my DIY attempts with solvent cleaners, wet and dry paper
etc are even worse. How do they get that 'brushed aluminium' effect?
Has anybody come across a successful method of finishing surfaces of
alu? I'd need details - grade of sandpaper, type of tool used - orbital
sander, belt sander, hand finishing etc. It would be a real help to fix
this situation without having to resort to anodising. On the other
hand, maybe anodising is the way out. Any views and experiences? Andy



Andy, you're getting some very enterprising suggestions but I reckon the
answers in the question - for me, nice bright colours are the new black.

Whiz down to Halfords and grab a can of suitable spray enamel. A little bit
of a rub-over with some wet & dry for a key, waft it over with the spray can
and it'll be touch-dry in summat like 10 minutes!!.

Personally, I have a penchant for the pastel shades of 70's Group 2
sanitaryware colours (pale pink/yellow/blue and cream &c) and would have my
Harley/XK120/Valve Amplifier thusly sprayed, but if you want summat a bit
more striking go to South Beach, Miami for your colour 'inspiration'.

http://www.miamibeach411.com/photo-g...-tower/001.jpg

http://www.geraldbrimacombe.com/East...night%20LR.jpg

??

:-)

On 21 Feb 2006 11:06:26 -0800, "Andy Evans"
wrote:

Like may people I use aluminium in equipment cases - in my case for top
plates for valve preamps and amps. I use 4mm alu, which Fays Metals in
Acton London supply and cut to size. It's not great looking in its raw
state, but all my DIY attempts with solvent cleaners, wet and dry paper
etc are even worse. How do they get that 'brushed aluminium' effect?

They use brushes - and anodising baths.

Has anybody come across a successful method of finishing surfaces of
alu? I'd need details - grade of sandpaper, type of tool used - orbital
sander, belt sander, hand finishing etc. It would be a real help to fix
this situation without having to resort to anodising. On the other
hand, maybe anodising is the way out. Any views and experiences? Andy

Have it brushed and anodised professionally, or just use Hammerite.

--

Stewart Pinkerton | Music is Art - Audio is Engineering

In article . com,
Andy
Evans wrote:
Like may people I use aluminium in equipment cases - in my case for top
plates for valve preamps and amps. I use 4mm alu, which Fays Metals in
Acton London supply and cut to size. It's not great looking in its raw
state, but all my DIY attempts with solvent cleaners, wet and dry paper
etc are even worse. How do they get that 'brushed aluminium' effect? Has
anybody come across a successful method of finishing surfaces of alu?

My recommendation would be similar to those of others.

Find someone local who can clean/anodise the chassis. This can be done in
various colours/finishes if you wish. A skilled anodiser can produce a
superb appearance.

However as Iain has pointed out, note that the anodising produces an
*insulating* layer on the surface. So mask off any areas which you need to
ensure remain conducting for ground contacts, etc - or be prepared to
abrade them clean of anodising afterwards.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

Jim said:
However as Iain has pointed out, note that the anodising produces an
*insulating* layer on the surface. So mask off any areas which you need
to ensure remain conducting for ground contacts, etc - or be prepared
to
abrade them clean of anodising afterwards.

Hello Jim. Thanks for your views here. For a finished product it does
point to anodised. I wasn't aware it wasn't conductive, so that's worth
knowing. I'm assuming that I should cut out main holes before
anodisation - holes for tube sockets and XLRs for instance. But then I
should drill holes holding the top plate to the chassis after
anodisation so the screws make contact with the aluminium. This sounds
logical doesn't it?

In article .com, Andy
Evans wrote:
I'm assuming that I should cut out main holes before
anodisation - holes for tube sockets and XLRs for instance. But then I
should drill holes holding the top plate to the chassis after
anodisation so the screws make contact with the aluminium. This sounds
logical doesn't it?

Drilling holes after anodising will only ensure that the insides of the
holes are clean, and there is no guarantee of contact here. You need a
small area of the flat surface around the hole to be clear, so that
washers, nuts and screwheads make contact. There's probably a special
rebate drill that can do this neatly, otherwise it might be enough to use
those spiky washers that bite through the surface oxide. Don't forget to
file away the oxide around the edges of the top plate, and the parts of
the chassis with which it makes contact.

Rod.

Roderick Stewart wrote:

Drilling holes after anodising will only ensure that the insides of
the holes are clean, and there is no guarantee of contact here. You
need a small area of the flat surface around the hole to be clear, so
that washers, nuts and screwheads make contact.

Ah, I assumed the holes were being tapped.


There's probably a
special rebate drill that can do this neatly,

A milling cutter called a slot drill will produce a flat-bottomed hole. If
well centred, it could put a tidy shallow rebate around a drilled hole.


otherwise it might be
enough to use those spiky washers that bite through the surface
oxide.

I'd scrape/sand off the anodising from a small area inside, and fit an earth
point with a serrated washer and tag.


Don't forget to file away the oxide around the edges of the
top plate, and the parts of the chassis with which it makes contact.

Not so keen on that - the filed edges could tarnish and acquire resistance.


--
Wally
www.wally.myby.co.uk
http://iott.melodolic.com

Andy Evans wrote:

I'm assuming that I should cut out main holes before
anodisation - holes for tube sockets and XLRs for instance.

Yes.


But then I
should drill holes holding the top plate to the chassis after
anodisation so the screws make contact with the aluminium. This sounds
logical doesn't it?

You could drill the holes before anodising, and tap them afterwards. That
way, if there are any mishaps during the drilling, you aren't adding the
price of anodisng to the scrap box. (The taps should cut through the
anodised surface insde the holes without difficulty, BTW.)

AAMOI, how do you drill? Do you centre-punch and drill, or do you use a
centre drill to start and then do the hole? Do you clamp the piece before
drilling?


--
Wally
www.wally.myby.co.uk
http://iott.melodolic.com

"Wally" wrote in message
. ..
Andy Evans wrote:

I'm assuming that I should cut out main holes before
anodisation - holes for tube sockets and XLRs for instance.

Yes.


But then I
should drill holes holding the top plate to the chassis after
anodisation so the screws make contact with the aluminium. This sounds
logical doesn't it?

You could drill the holes before anodising, and tap them afterwards. That
way, if there are any mishaps during the drilling, you aren't adding the
price of anodisng to the scrap box. (The taps should cut through the
anodised surface insde the holes without difficulty, BTW.)

It is much better practice to drill and tap before anodising,
and then fit plastic machine screws into these threads, to keep
tjem clean.

Then you do not need to put your anodised panel under the
drill press any more. I have learned this the hard way:-)

Iain

Iain Churches wrote:

It is much better practice to drill and tap before anodising,
and then fit plastic machine screws into these threads, to keep
tjem clean.

Like little grub screws? Fine if you have them handy, I suppose...


Then you do not need to put your anodised panel under the
drill press any more. I have learned this the hard way:-)

If you've drilled it before anodising, then it shouldn't need to go back
under the drill - provided you can spin a tap in a straight line. :-)


--
Wally
www.wally.myby.co.uk
http://iott.melodolic.com

In article , Iain Churches
wrote:


It is much better practice to drill and tap before anodising, and then
fit plastic machine screws into these threads, to keep tjem clean.

Again, I'll support what Iain says here. The standard approach in my old
lab was to use plastic screws to 'mask' the region around holes if we
wanted those locations as electrical connections after anodising. This is
in addition to using a 'scrape' washer when the final connection is made
after anodising.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html