brushed aluminum finish, how to?

[cowanrg]

for home use, ive been using a bench sander, then a hand sander (wooden block with paper attached), then finishing it off with scotch pads.

its slow going, but has predictable results. its pretty fool proof. the face plates on my avatar are taking around 1.5 hours per fin. because of the perfection of the machining work, we have to get the finish perfect too. you could easily get this done in an hour or less if you werent trying to get it perfect.

[Peter Daniel]

Actually the grain direction is dictated by the material. You could go across the natural grain of aluminum, but the results are always better if you go along. I tried few times doing it across.

[sam9]

I've used the hand method - a sanding block wider than the workpiece starting with moderately coarse wet&dry (use wet) paper until the scratches and dings are gone, then progressively finer paper until it looks right. Tricks: find a way to hold the workpiece adsolutly immobile B: stand, sit ot squat in a postion that helps you make complete strokes from one end to the other and as straight as possible C: count the strokes after fixed number reverse the workpiece and make the same number from the opposite direction (otherwise one end will tend to look different from the other) D: lots of soapy water E: wear old clothes and don't be afraid of making a mess.

I have not bothered with alodine yet - I'll try that on the next project

[jewilson]

Aluminium Oxide sand paper is the best for metal it will not wear out as fast. You can use granet or other woodworking sand paper they just don't last as long. If you have a Drum sander Aluminium Oxide is a must.

[Jason_N]

Changing the subject slightly...

So what can you do with the aluminum after you are finished brushing? I would like something that is clear (or close to it) and that I can do myself. What are the options?

Thanks,
Jason

[Peter Daniel]

Alodine. If you want to have it close to clear, use very light solution and brush any excess after. The pic I posted previously shows the alodined piece. You can also use some protective spray, but this will always look artificial.

[jewilson]

You can spray it with a polyurethane or Lacquer it has to be clean of all oils. Don't get you finger on it. If you spray it, the aluminum will lose some of it ability to conduct heat, so don't spray the heat sinks. Anodizing is cheap and doing Alodining is cheaper, call around and anodizing can be done in many colors .

[sam9]

Anyone know a good source for the solution?

Can anyone suggest a URL with instructions for applying it?

I did a Google search and got a huge listing that I haven't had time to sort out so if anyone can point to some sources they can recomend from their own experierce . . . .

[Peter Daniel]

http://www.airtechcoatings.com/cgi-l...&search=action

Buy the smallest amount in powder form. When making solution Use quater or less of what they recommend (when mixing) as the original receipe makes the liquid too strong.

Don't buy aluminum prep (or any cleaner) as it doesn't work well and you don't need it.

When doing actual alodining, clean the parts directly before dipping (with scotch brite). Don't dip it for more than few seconds, as the color becomes too strong and you might not like it. Extent time for required appearance. If finish is too strong or uneven, additional scotch brite brushing (after alodine) fix the problem.

Check also this older thread for more suppliers Make your stereos look good without anodizing.

[sam9]

Thanks much. I'll bookmark those for my next project.