DIY "Anodizing"

[steenoe]

Here is a simple way of making a nice aluminium surface.
The method is widely used for treating the surface on
aluboats, and is remarkably strong against oxydation.
It results in a silky smooth surface, that is very easy to
keep clean and nice. Here we go:
The piece of alu must firstly be brushed so the surface is
absolutely smooth and homogen to look at. The easiest
way to "brush" is actually with sandingpaper. You need
good quality sandingpaper for this. The cheap stuff won't do.
Also it has to be a little coarser than you would think.
120 grid is a good starting point. You have to be very
meticulous at this point. Your sanding strokes must
be even, in the hole length of your piece. The surface will be a little rough, but this will go in the next step.
A serious warning: You really need a pair of rubbergloves for the
next step, as this stuff eats your skin for breakfast! No kidding.
Dont get it on bare skin or into your eyes.
Your piece of alu must be washed with a solution of NaOH
dissolved in water. I have used about 3 good spoonfull's
for 2 cups of water.(NaOH= Caustic soda). It is done in much the same way as when sanding, only I use a Regular kitchen sponge
for the job. The rough green side of it . Just soak it often, as you stroke back and forth. Keep stroking for about 5 minutes.
The solution is not allowed to dry up on the piece of alu, as this
will get very stained. When done, rinse the piece very well
under tap water. Dry the piece and you are done!
If you are not satisfied with the result, work at it again.
There you have it. It is not excactly Anodizing, but it looks
very good. In all cases it looks way better than raw alu
I attached a pic of my stereo, the preamp (BosoZ) is fitted with a faceplate made in this manner. It is about a year old now and looks like the day it was made.
Hope this will be useful for all you DIY'ers.
Steen.

[SY]

I can't stress your safety warning enough- sodium hydroxide will turn you into soap and can be deadly if not handled properly. Thick, alkali-resistant gloves, safety glasses, and proper chemical disposal are MANDATORY.

[Sch3mat1c]

Yep, neutralize with vinegar...

FYI, this process is NOT anodizing, AT ALL. It is chemical etching of the aluminum.

Can also be done by soaking in a tub of lye solution, no rubbing or sponge needed.

BTW, I'm suprised the average sponge isn't eaten alive by lye..?

Tim

[SY]

Depends on whether or not it's a natural sponge. Some synthetics do very well in alkaline solutions. Natural sponges do less well.

There's a spongeworthy joke in there somewhere for all you Seinfeld fans.

[Geek]

For some black (well, black/blue) anodizing, try a tube of "Cold gun blue" from a gun store. It's original use is for "blueing" of untreated (like, where you sanded the rust off) spots on your guns, but works on many other metals.

The warnings on the tube are minimal, but it is selenium based and should be treated as any other selenium/asbestos product....well ventilated room, rubber gloves, goggles and dispose of rags in an approved way.

[steenoe]

I took some closeup pic's of the surface as it looks after
having had this treatment. The "Spongeway" is used
because you can make just a small amount of the solution.
This is more environmentally friendly.

Steen.

[steenoe]

And still closer

[steenoe]

And the sponge.
I am sure your girlfriend would have hoped you knew that one.
From the kitchen that is.....

[adalin]

Nice..

I will experiment a little I think... Might just be the right treatment for my current project...

[Bill Fitzpatrick]

what is the source of those flaws on the panel?