Removing Anodizing...how do you know when you're done?

I am removing the anodizing from the A-arms on my Vette IFS using EZ Off, as was recommeded by some folks on this board. I sprayed a liberal amount of the oven cleaner on the part and let it sit for 20 mins, scrubbed the part with a brush, and rinsed it off. The A-arm looked pretty much the same with just a few areas that appeared dull. I applied the EZ Off again and let it sit longer, this time the color of the A-arm is almost all dark gray. I dried it off and started buffing it out with a 3600 RPM buffer, 8 inch sewn wheel, using tripoli compound. The gray is not coming off, it just gets a little shinier with the buffing. I believe that the anodizing is still on the surface but I am hesitant to put any more EZ Off on it. Suggestions?

 

Close-up of another side of the arm...

 

I"m not a buffing xpert, but I think you gots to start with something a little more coarse than tripoli. I would consider sandblasting with fine sand and then go from there. kind of like buffing and polishing an alum. intake manifold.

 

Try cleaning the oxide layer off with rubbing compound.Then polish.

 

Or even some 220 sandpaper.......

 

220 might be too coarse

 

400 grit makes it really easy to buff, but the paper clogs up pretty fast. 220 will buff out, but it takes some time. Maybe try a wire wheel, but be careful because it sometimes leaves a funny texture that you would have to then sand down.

-Bugman Jeff

 

get yourself a 3M deburring wheel that fits on your bench grinder grade 7s superfine it will take off your anodizing and prepolish it for the buffer. its on of my most used items in the shop. they are about40-60 bucks and last about 2 years.

 

It looks some corrosion has penetrated the surface.
Try "glass beading" them until they are "snow white", then start polishing. Start with a course compound, then the tripoli.

 

Well I have been at this now on and off most of the weekend and I have found a few techniques that appear to work better than what I was doing previously. After I got over my fear of sanding the piece down too much, I got to work with the 1" belt and DA using 180, 220, and 320 grit paper. I have some 3M wheels but they're too wide for my buffer (6" wide with a 3" arbor). Here's another pic showing the other A-arm prior to removal of the anodizing and the first arm that I have been working on. I still have some work to do on it but it's alot farther along than it was yesterday...

 

Now that's starting to look very good!!

"Determination is the key to sucess!!"

 

The brighter sparkly bits are anodising left on the piece.
You should be using a pleated buff, preferably mill treated with a coarse stainless compound if you want to polish it fast, but I recommend you go over it with 160, 240 and 320 grit first, if you want to do a real good job take it to 600 grit before you go onto regular abrasives. Your surface is way to rough for tripoli, the coarsest tripoli i have encountered needed an 800 grit finish or better before it really did a job.
you can get tyo where you need by using either paper or greaseless compounds.

 

Well your getting there, keep the sanding through to 600 grit, 800 is even better, then powerbuff with a coarse stainless compound, and a mill treated canvas buff, that'll give you a decent mirror, then go to a fine stainless compound and mill treated canvas buff and finish it with a good calcined alumina or chrome oxide and a plain canvas buff, Now you'll be able to shave in it.give it w wipe with showmans blend for protection and seal it and you'll be good to go for 4 to 6 months before needing to wipe over the exposed areas.

 

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Well your getting there, keep the sanding through to 600 grit, 800 is even better, then powerbuff with a coarse stainless compound, and a mill treated canvas buff, that'll give you a decent mirror, then go to a fine stainless compound and mill treated canvas buff and finish it with a good calcined alumina or chrome oxide and a plain canvas buff, Now you'll be able to shave in it.give it w wipe with showmans blend for protection and seal it and you'll be good to go for 4 to 6 months before needing to wipe over the exposed areas.


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I have three bars available: brown tripoli, white color, and gray stainless. I'm not sure how course the gray compound is but it does "feel" grainier than the tripoli. I have been using my cheapie 3600 RPM buffer with 8" wheels. I have a 1 HP 1800 RPM Baldor with 10" wheels that I intend to use once I get these pieces scratch-free and ready for a final buff.
What is a "mill-treated canvas buff"? I have two wheels that are white and yellow canvas "rippled", I believe that the yellow one is referred to as mill-treated.
Do you sell kits at EnglishPolishing that have all these various products in one package? I intend to treat these pieces and my wheels with Zoop's Seal to preserve the shine. Thanks for the tips...

 

Your gray bar will cut better than the tripoli, the white bar will be an aluminum oxidwe most likely.
That is generally a bit finer than tripoli.
The yellow rippled buff is a mill treated canvas buff, the term is pleated.
Your plain canvas should be pleated too.
We can set you up with most everything you need, but seems to me you've already got it.
Not knowing who supplied your gear I can't tell you how fine the white bar is, but assuming it is aluminum oxide, you can improve on that again by using chrome oxide or calcined alumina, but most regular aluminum oxide is still a pretty good finish.
I would preserve the finish by going over it with Showmans blend.

 

If your oven cleaner is like the stuff we get here you need to soak the part then seal it in a bag overnite. Also I have had good results with a mild acid rust remover such as Jenolite (much quicker about an hour or so depending on how deep the anodizing has etched)