Making Aluminum Parts Like New Again; I.E. Clean But Not Shiny

[morrisey0]

Hello All

Most of the time when I am restoring aluminum parts, I go down one of two paths: 1) leave them with a scuffed (scothbrite) look, or 2) polish them shiny. I like both of these looks, but for what I am working on now, I would like to get to "original" look. Just plain, clean, non-shiny aluminum. Most of the parts I have are scraped up, scratched, slight pitting, etc, so they will need to be worked down to level them out, but what is the best way from that point to get to new aluminum look? Is there a good range of sandpaper grit that is just between scuffed and polished? I have a vibratory tumbler that I use for other projects, anyone with experience using one with aluminum? What do you do for maybe aluminum parts look stock?

[juicedcoupe]

I use the foam sanding blocks from Lowes, Home Depot, etc. I like the fine/medium combination blocks.

The fine will leave a shiny but not polished look. The medium is good for removing oxidation and scuff marks.

[Lavigna]

I've had good luck using Lye. I use it mostly to remove anodizing, but I notice it also brings the aluminum back to a dull finish. Be careful not to keep it on too long, or else it can eat away the aluminum.

[Lowgear]

I'd like to know others experiences as well. Whenever I've refinished aluminum before, the answer was to always polish it. Now that I'm a bit older, I really appreciate the different ways it can be refinished a lot more. Polishing is really nice but it takes away that 'tough' look, and leaves the material looking cheapie or plasticky a lot of times. It also has a tendency to round off edges.

I bought a vibratory tumbler many years ago in the hopes of being able to throw aluminum parts in there, and have them come out the way I wanted without having to do it by hand. The only media I've tried so far is treated corn cobs which I'd stay away from. They never did all that much no matter how long I left the aluminum in for, and worst of all they break down and tightly pack themselves into every single nook, cranny, and hole. There's a lot of information out there on tumbling aluminum. Unfortunately, I don't have the money or time to try out multiple experiments too much.

I currently have a lot of aluminum pieces I'm slowly in the process of refinishing, and it would be nice to know what others have done to achieve various results.

[sandkil]

On really intricate aluminum parts I use a airbrush mini sandblaster.
Not to be used on larger surfaces as you will be sitting there for quite a while.

https://www.amazon.com/PointZero-Airbrush-Sandblaster-Eraser-Etcher/dp/B004KNAH06

[Coelacanth]

400 grit wet-sanding gives aluminum a nice satin finish that I think is pretty close to the original cast aluminum finish. Try on a test piece first.

[jwscab]

I usually use scotch Brite to bring back a mostly raw finish. You can use high grit sandpaper, like 820 or something. Another great way to get a raw aluminum finish is glass bead blasting. That's probably the best.

[Lowgear]

That's what the plan is for what I'm doing. Tediously sanding everything using various grits of sandpaper to remove imperfections. Then glass beading everything to get a uniform finish. Then finally using Scotch Brite pads for the final finish. I'll do a test piece first of course to see if it achieves the result I'm looking for.

It was supposed to happen this past spring/summer but life got in the way as it always does.

[morrisey0]

The lazy-man technique that has worked the best so far is vibratory tumbler with green resin pyramids. The parts below were a bit rough, and all I did was run them trough an ultrasonic, rough sand the high spots, then threw them in the tumbler overnight. I have about 5 minutes of actual work on them, and the final finish is just about what I was looking for.

[Coelacanth]

The lazy-man technique that has worked the best so far is vibratory tumbler with green resin pyramids. The parts below were a bit rough, and all I did was run them trough an ultrasonic, rough sand the high spots, then threw them in the tumbler overnight. I have about 5 minutes of actual work on them, and the final finish is just about what I was looking for.

Nice...those look about as original as you can get. It's great that it was also so little elbow grease.

[jwscab]

Most aluminum parts you get will be tumbler polished, so that all the edges are broken and flash removed. So it's likely that's the original finish.