Originally Posted by FIRE UP
Thanks for the nice comments. You were pretty close in your "stages" of polishing. Aluminum is primarily a soft material. That is of course unless it's been treated in such a way that it's NOT soft. Some examples are 3003, 5052 and 6061-T-6. The first is primarily bubble gum aluminum. It's really malleable and scratches very easily. The 5052 is the middle of the grade chain and, is used in many applications for basic industrial support. The T-6 stuff is the bottom of the line in terms of Air craft quality aluminum. There's higher grades than that but, you get into exotic formulas and all that.
The wheels we all use and see on our coaches are a form of a mix of the 5052 and T-6. They need to be strong and hold their shape but, on the non-coated ones, they are soft enough to actually polish and that means, REMOVING material. But, due to the fact that they are that soft, on the surface anyways, it also means they're somewhat easily corrodible.
Metal, as in steel and cast iron, rusts. Aluminum corrodes. Same thing only different.
This brings me to the beginning of the polishing world. Most alloy wheels that come on the coaches we purchase, have a fair to mildly good polish on them from the factory. Not bad but, they can be improved on. If I had to guess, I'd say that more than 50% of the folks that purchase coaches with alloy wheels, NEVER TOUCH THEM for the entire amount of time, they own the coach. When that happens, THEY CORRODE, (unless coated). When that happens, they get dull because, just like what rust does to metal, it OXIDISES the surface.
And, the harsher the environment they're subjected to, the deeper the corrosion is, along with the time frame at which all this happens. By harsh environment, I'm talking a coach with un-coated wheels, living at or very near a beach. The salt air is ugly stuff. Running around back east during the snow and heavy ice season is not good too due to the SALT they use on the roads.
Now, all this leads up to, what kind of condition a set of wheels are in when one wants a mirror finish. Well, if you look at an alloy wheel and, it's pretty dull, but, with your thumb can almost bring a better surface, that's an easy fix. Some regular Mothers paste will do that wheel just fine. But, if you encounter a dull wheel and, no matter how much you rub your thumb on it, it remains dull, you'll have to get down and dirty with a bit more aggression.
There are rouges that are formulated for aluminum. They're formulated in different colors. Brown is normally for aluminum and White, for stainless steel. There's a green and a black too. I forgot what those are for. But, If you watch a pro, and they start with badly corroded wheels, it's highly possible that you'll see them use SAND PAPER on them.
I did. I had a set of GL 1500 Honda Goldwing wheels with 145,000 miles on them and, like stated earlier, they'd never been touched. I had to use 320 grit wet-or-dry to break down all the pits on them. Then, 400 grit, 600, 800, 1000 and finally 1200, all with tons of water to carry away the material. Then, I used a 3" tightly sewn cotton wheel on a 2500 rpm drill motor, along with the BROWN rouge.
That brought them back to the factory finish. I was not satisfied with that. I then used another, clean, cotton wheel with what's called "Semi-Chrome". It's a paste and, for the most part, produces enough of a shine that about 98% of the folks that use it are completely happy with the results. Not me. Once done with that process, I used what's called Zepher 40 and my finger with microfiber cloths. That process alone took me about two hours on each wheel.
All in all, with all the stages of process's, I had about 10 hours in EACH wheel. But, when they were done, they were as close to CHROME as they could get. It's all about breaking down the surface to a finer and finer finish. There are many recommendations as to what to use from folks on here and other RV forums. Different formulas and brands, are sold in different parts of the country. But, for the basics, the brown rouge can be bought at many auto paint supply stores and a few other specialty hardware stores.
As for the pastes and liquids, those too are easily purchased it many auto parts stores, specialty auto paint stores, detail shops and more. Good quality microfiber cloths or, any form of a cloth that is ultra soft is importance too.
Now, once a wheel is brought to the finish desired, it will last a long, long time without any maintenance. But, it's deceiving. You polish a wheel, and, you're real happy with it. So, you keep looking at it as time goes on and, it keeps looking good so, you don't mess with it. Pretty soon, a years gone by and, you THINK it's still good.
But, sit down and with a little Mothers, do a small section. WOW! you'll see that, it has corroded or, "oxidized" to a duller surface than you think. You hit those wheels with about 20 minutes of maintenance, once a year, and they will remain a mirror.