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Now that I've got the rust on my table saw taken care of, I realized that my 25 year old miter saw base could use a little love.

Poor, unloved miter saw base with oxidation

The majority of the saw is made out of cast(?) aluminum, so it hasn't "rusted", but it does have an uneven coating of oxidation on it, and it's got some fairly noticeable machining marks on it (from new), with the darkest of the oxidation seeming to be in the deeper grooves from the machining.

While I used naval jelly to clean the cast iron table saw, I don't believe that's appropriate for cleaning aluminum. (And, I don't want to chance it taking the lettering off the miter gauge, etc.)

I gave it a quick pass with the RO sander with 220 grit paper (straight off of duty cleaning up the table saw), but that didn't seem to help much. I don't want to sand it too much, as I believe the aluminum would be much softer than the iron, and I can see where it would be much easier to end up with an uneven surface if I'm not careful.

What chemical or mechanical methods would be appropriate for cleaning oxidized aluminum surfaces while providing minimum risk for damage?

Of course, I realize the answer may just be "leave it the heck alone and use it more", but after seeing how (relatively) easy it was to spiff up the table saw, I'm motivated to get this looking shiny and new again.

FreeMan
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  • Looks a lot like aluminum. Why do anything? Maybe buff it with very fine abrasive like 600 grit. I would not do anything with chemicals. – blacksmith37 Sep 16 '21 at 21:29
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    @blacksmith37, looks like aluminum? It says it is right in the title. – Graphus Sep 16 '21 at 22:34
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    I'd be tempted to leave this alone other than giving it a thorough cleaning. I'm actually fond of the mottled appearance like you have here, although obviously it's not to every taste. BTW the reason you're having difficulty when sanding is that the oxide that forms on the surface is aluminium oxide, literally the same stuff that industrial abrasive is made from. You have to get that off/get underneath it before you make any appreciable headway when surfacing aluminium. – Graphus Sep 16 '21 at 22:40
  • Automotive polishing compound? – gnicko Sep 17 '21 at 13:03
  • It's OK, @blacksmith37, I've had more than my fair share of reading comprehension fails lately. :D:D:D – FreeMan Sep 17 '21 at 13:52
  • TBH, @Graphus, I had never thought to clean it up until I looked at what a bit of elbow grease did to the table saw. Also, I'm considering just giving the surfaces a good waxing, but I'm not entirely sure I want the wood sliding across the table of the miter box all that easily. Once I've got it aligned, I'd like it to stay there for the whole cut! (yeah, I know, once the blade's in it, it's unlikely that the wood would move...) – FreeMan Sep 17 '21 at 13:54
  • I've been trying to remember what I've read or heard about mitre saws over the years re. having the surface waxed and, well, I got nothin'.... probably because I consider them very much non-essential and my subconscious doesn't care to hold on to much info related to them ^_^ – Graphus Sep 17 '21 at 14:33
  • That seems like a good idea, @GregNickoloff. Might give that a try. Of course, I would have to go shopping first, as I don't tend to care for my car's paint jobs all that well... – FreeMan Sep 17 '21 at 14:52
  • Disassemble, sand blast, anodize, and dye. Dark blue would look great with the yellow plastic. – Caleb Sep 17 '21 at 21:23
  • Adds blasting cabinet to shopping list... – FreeMan Sep 18 '21 at 00:08
  • Just as a general point, you want to be very careful blasting machined surfaces or reference surfaces. I don't think it would matter hugely here, unless excessive blasting were done (very hard & too coarse media, with too long linger time in various spots) but wanted to mention it. Anyway, it would be good if we could get some sort of reasonable Answer here so this doesn't end up unanswered. As I suspected I would I found a Internet Favourite for cleaning Al, and it involved vinegar.... as far too much of the cleaning advice online seems to (and too often stupidly combined with baking soda!!!) – Graphus Sep 18 '21 at 18:06
  • I wasn't actually going to disassemble and media blast! :) Though I wouldn't mind having one for cleaning up car parts. A good answer would be nice, but I really think I'm leaning toward "leave it the heck alone". – FreeMan Sep 18 '21 at 18:53

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Maybe try automotive/marine aluminum polish like used on aluminum wheels and so forth.

Or, maybe something like this Aluminum Cleaner/Brightener/Restorer which seems to be a non-abrasive approach.

Caveat: I have no first-hand experience using these products on miter saw tables (I'm good with it as it is) but have used the polishing compound on wheels over the years and they do a good job.

gnicko
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  • I'll give you the check mark. If something notably better comes along, I reserve the right to change my mind... :) – FreeMan Sep 20 '21 at 17:51
  • Fair enough. If I think of something better, I'll post another answer... Actually, I was looking at the aluminum base of my saw last night and I've been thinking about it since... – gnicko Sep 20 '21 at 19:36
  • @FreeMan, FWIW I was very much thinking this was a case where you might just want to go with a commercial cleaning product if you weren't going to leave it as-is. After looking at the Internet's advice on home-brew solutions, practically everywhere seemed to be mostly or entirely parroting the same basic advice; this is less than satisfactory to say the least even IF it were sound, which I'm certain it isn't. – Graphus Sep 20 '21 at 21:07
  • Brain-worm created. My work here is done... :D – FreeMan Sep 21 '21 at 11:27