Aluminum Matte Finish

[Tazzer]

I am currently working on this project for a company that I am helping out while I am still in school. They want to add a matte finish features to a couple parts. This is the first project they gave me and I have never really seen this done. Well not in a way they want it done. See they don't want to mask off the piece and sandblast, etch etc.., they want to bay able to do it in there cnc machine.

The only thing I can thing of is using a 15 degree v-bit and do a cut at small increments and small depth.

I was wondering if anyone has any other suggestions or ideas on a way around this?

[HuFlungDung]

Some guys mount a small wire brush in a toolholder and use the cnc to brush a finish onto the part. With a little imagination, you can make some kind of a toolpath that will give pleasant results.

The other method is by tumbling the parts in a rotary tumbler with a suitably shaped media.

[BT1]

Tumbling is also quite good for deburring, especially when you have sizeable quantities of parts.

[Swede]

Tazzer, have you considered engine turning? Chuck a rubberized abrasive like a Cratex or similar, and program a series of downfeed commands for overlapping coverage.

If you can possibly do it without CNC, try this: A very nice, non-directional matte finish can be created on aluminum with a palm, vibratory hand sander (like a Makita or Ryobi) loaded with 400 grit wet/dry. Spray the surface liberally with WD-40 or any light oil (you can use water too, watch out for electricity), and simply apply the sander to the aluminum. It leaves behind a very pleasant matte finish, without any directional "grain" such as what you'd get with a sanding block stroked in one direction. Try it!