Tech...Polishing anodized aluminum trim

I was requested to do a tech piece on how I polished the grille and brightwork on the wagon. First off I want to say that this is how I did it. There may be people on here who have done more of this than I have and may chime in with their comments and/ or suggestions.
The first thing you need to do before you can polish anodized aluminum is remove the anodizing. The anodizing is a hard coating that sandpaper and polish can't touch. I use easy off oven cleaner. It's basically sodium hydroxide or lye. It's not as harsh or as aggressive as pure lye , so it works a little slower. I sprayed the piece and let it sit for a bout an hour.

Here's the piece before any work has been done


this is how I removed the anodizing...make sure you wear rubber gloves



This is what it looks like after the anodizing is removed. It turns a dull silver/grey .Theres a untouched piece next to it to compare



After it's been stripped it is time to pick and file out the dents and sand out the pits and scratches.





Work progressivly finer till there are no more scratches . I use 220grit followed by 320 grit finishing with 600 grit.

 

This is the kit I used . There is enough stuff in there to do quite a bit. The kit cost about 40 bucks. I had a couple of buffing wheels on my grinder already that I also used.





I started buffing with white compound. Make sure when you're using the buffing wheels you don't catch an edge or it will fling your work and probably bite you.



Work your way around the piece going several different directions till all the sanding scratches are polished off.



Once you are done with the white, move to the other side and do the same with the red compound. It will bring up the lustre to a mirror finish.





The only thing left is keeping it shiny . You'll have to use aluminum polish every once in a while to keep the shine. The anodizing used to protect the metal at the expense of some shine. It will also scratch easier but it's easy to repolish...

 

nice tech---well done, thanks

 

good tech, thanks, i got some pieces to do on my 57

 

Good tech.
Here's a couple of extra tips to maybe improve on it a little.
Stripping is easier if you throw some sodium hydroxide into a plastic tank or bowl and dilute to strength you need.
I only use oven cleaner on really long bits.
(The wife won't let me use the bath tub.)
Then it's real convenient.
Waste is safe to dump, or run to ground.
As aluminum and sodium Hydroxide it is not controlled.
Your red abrasive is probably not much finer than the white.
It is for gold and will leave a faint stain in the aluminum.
You should be able to see the difference if you wipe off with alcohol.
I'd have started with a decent co**** stainless abrasive, then gone to a regular white bar to finish.
If you polish consistantly one way with your first cut, it is easier to cross at 45 to 90 degrees on next cut to remove scratches.
If you have a wooden bench, mount the buffer on a 2X10 and cut around the machine leaving enough planking behind it to anchor both sides of the bench with the buffer sticking out front maybe 12 to 18 inches.
Use Copper or plastic tubing to push your buffs out to the end of the shafts to improve clearances on the buff machine.
Fit little plastic caps over your clamping nuts beside the buff, then it you touch them with a piece it won't hurt it.
Hand polish the finished pieces with a pH. Neutral waxed aluminum polish to reduce repolishing to a minimum.
Nice little tech.
Well done.

 

thanks polisher! good tips.

 

Thank you Jethro and Polisher... Now I need to get busy.

 

Thanks Polisher!
I was hoping you would have some wisdom to share. Like I said it's just how I did it and not the only or even best way to do it. I am happy with my results though and with some practice and patience I'll get better.
It sure is a filthy job ! My garage is full of dirty black fluffy lint all over the place.

 

Polisher's ECP Custom Blend is fantastic for keeping the shine.
​

 

You can keep that fluffy nasty **** down by putting a fan in a window behind your buff and by running big old fashioned evaporators either side of your machines or shop.
They put moisture into the air and make the dust drop.
If you use a vacuum to clean up always empty it after and swap bags if you go from aluminum to steel.
Otherwise the buffing dust can interact and you can get one hell of a firework.

 

Also, wear a respirator when polishing, the dust created is very harmful to your lungs.

 

Outstanding Tech article!

 

i guess you can do this on sheet metal also?

 

when you mix up your sodium hydroxide solution what ratio do you suggest. also why would you need different concentrations? thanks

 

Good tech. I am doing a similar system to polish my stuff. I found that the red compound will take the anodizing off pretty easily but does leave residue. Then I start with course paper to get the rest off working down from 150 to 280 to 400-600-1000-1500-2000 then buff with white compound. When I get pretty good with the white, I use some real good quality buffing compound, the wizards turbo cut on a clean buffing wheel. That gets the tiny scratches out that the white will leave. It turns out like gl***...but takes like &ucking forever!
Stainless is similar. For a piece without blems, I start with 600-1000-1500-2000 paper then buff red-white-polish and it looks better than new. I will even buff brand new bumper bolts with red-white-polish and they look killer on new bumpers.

Good luck all!

 

Bringing this back up from the dead with a couple of questions. I am trying my hand at polishing an anodized grille. I have dis***embled it and stripped the anodizing off. I purchased an aluminum polishing kit that looks su****iously like the OPs except mine was from harbor fright and only $16...it has all the ***orted buffs and three sticks of compound; black, brown (red?), and white. The destructions state that the black is emory for course buffing, the brown is Tripoli for medium buffing, and the white is fine for final polishing. In this tech I see where the Op went white first and then red...I also see where Polisher suggested that the red is probably not much finer than the white. Ive put in a **** ton of prep sanding from 320 all the way up to 2000 and then hitting the pieces with a trizact pad and Im not getting anywhere near the results the Op got with wayyyyy less steps involved...so what am I missing here guys??

 

Two thumbs up. Thanks for posting.

 

I use corn starch to clean newly buffed aluminum pieces, it picks up the little polish smudges sometimes left behind.

 

My pieces still look cloudy after polishing. Ive experimented with skipping the emory and using only the red but still yield the same results.

 

Might be a dumb question but you are not using the emory and the red on the same buffing wheel are you?

 

No. The kit I purchased had an ***ortment of wheels so I picked out the largest two hard buffs and have been using one for emory and one for the red, or brown as its called in the instruction pamphlet. Im missing something simple though Im sure.

 

Probably just not giving it enough time. It is a time consuming operation.

 

I just found my hard copy from about 6 or 8 years ago when polisher gave very thorough instructions on polishing. Thanks for bringing up this topic again.

 

Nobo, any chance you can scan them or post them up? Id love to see what he advises

 

Your polishes are probably good considering. 2000 grit should have kept the start part...as a very smooth first touch already. I just run it thru the wheel, with same polish and wheel in consecutive processes. Say for instance....all pieces polished with medium rouge wheel....then change out polish and wheel....and run the pile thru the next step of finer rouge. Three polishing grades, and 2000 grit should give you a magic shine....I would say. Puzzling to say the least. Good luck !

 

For final color buff, you really need a loose cotton buff. You do need to be careful with these, as they will 'grab' a part much easier, so a light touch is best. And for a quicker/easier alternative to sandpaper, look here:
http://www.xs11.com/forum/showthread.php?t=39869
You'll still need to remove the anodizing chemically if it's really damaged. But if it's only dull, you can buff it back to pretty decent condition without removal with the white compound and a loose buff. The bad thing about removing it is the aluminum will now be fully exposed to the elements and will scratch easier.

 

For final clean up use varsol and a soft cloth to remove any polish then buff with white flour on a clean soft cloth to remove the haze from the varsol. If it looks cloudy you haven't spent enough time on the first stage of polishing


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Hubnut, it might be about 60 pages. Polisher had made it available here on the HAMB. Maybe he will again?

 

If you need to clean up trim like this, you might try this first. T shirt type cloth dipped in acetone and polishing (not rubbing) compound. Worked for me on interior trim pieces for a 60s Chev, so I tried it on some exterior pieces I thought I was going to have to strip/polish. Hope it works as well for you as it did for us.

 

To make any progress with buffing you've got to have shaft mounted buffing wheels. Those little buffs in the HF kit are made for getting into tight places. A drill won't run enough rpms to give you the surface speed you need to buff. When running any sort of buffing wheels you have to rake them regularly else the buildup on the wheel will be putting scratches back on your surface faster than you can polish them away.

Heat is your friend when buffing. If the parts aren't getting hot, you aren't making progress.

With the right wheels and compounds, you should be able to wet sand your parts with 400 paper and go straight to the buffer.

White rouge is normally the recommended compound for final coloring on aluminum. It is used on a loose cotton wheel.

Other compounds for the previous steps are used with spiral sewn wheels.

Lots of good general info here http://www.tarheelparts.com/catalogreduced.pdf on which wheels and compounds to use on what metals, as well as a source for high quality buffing supplies.