Polishing attempt... window frames

[calindor]

Happy Canada Day!

I decided to use part of my holiday to play around with trying to get a shine on the aluminum window frames of our Biggar. I experimented on the inside of the window frame that won't be visible once installed.

You can see in the attached picture that I got a bit of a shine going, but not as nice as I wanted. It also was more labour intensive than I had thought.

This is what I did:

1st attempt:
used - sewn sisal buffing wheel on 1/2HP bench grinder with brown polishing compound
results - didn't even get through the oxidation (if that's what it is)

2nd attempt:
used - medium sanding drum on dremel then sewn sisal with brown compound
results - bumpy lumpy look, almost like hammered metal

3rd attempt:
used - 220 grit sand paper then sewn sisal wheel with brown compound followed by a loose cotton wheel with white compound
results - see attached picture

I think I need a step between the 220 grit and brown compound. Perhaps 600 grit sand paper... BUT here's the thing... I was hoping there was some way to do this all by using the buffer and not hand sanding every millimeter of the window frames.

The profile of the piece I was working on is like a simple 'S' (see other attached photo). I can't get into all these tight corners well enough with sandpaper, so that is another reason I was hoping a wheel would work. (Besides, my bad arm won't allow that much elbow grease without serious consequences!)

Does anyone have some previous experience or suggestions?

(For the record, I checked out Ian Giles' site and watched the video on polishing his aluminum hinges. He mentioned more info to come on how he polished the jalousie window, but I didn't find any.)

Thanks all!
Clayton

[Borrego Dave]

Hi Clayton, you may want to pull up some of Ian's posts on polishing as he is the polishing king here. They come out looking like chrome.

[MC1]

Good day Clayton

The window frames in our 40 year old Airstream were not pretty. Like you I tried a few things but had most success painting them. They turned out great and 10 years later like new.

I just sanded, primed, and painted with rattle can.

[Donna D.]

Check out Ian's blog about polishing aluminum. He's the MAN! It's about half-way down this page: Proud Canadian

[Ian G.]

Hi Clayton

I have polished all the aluminum on my Boler as others have mentioned. The mill finish aluminum the window frames are made of DO NOT need sanding, especially with 220 grit. All you need to do is use your sewn wheel with WHITE polishing compound (although you should not mix compounds on wheels, a new wheel should be used)
Lots of info and pictures on my build thread http://www.fiberglassrv.com/forums/f...tml#post433202
On my website (as Donna indicated) Proud Canadian



and finally here is my video on polishing the hinges, with the window frames no sanding or grinding is needed, just straight to the buffing wheel with white polishing compound.
NOTE: Polishing is VERY MESSY, you will get black aluminum oxide everywhere, tarp off the workspace with plastic sheets. Wear safety glasses or preferably a face shield and a mask. Always work in the direction the wheel is turning, don't buff against wheel rotation or it will grab the part and shoot it across the room

https://www.youtube.com/watch?v=85sRzxFyKRE

[Ian G.]

I cannot tell from the picture but there is the possibility that the window frames are anodized. Anodizing is a hardened protective layer that prevents oxidation and protects the aluminum. If that is the case it is not worth the effort to polish as that has to be fully removed first which takes a huge amount of work. Easy way to tell is to take some aluminum polishing cream like Autosol and apply some to the surface, if the cream turns black then it is raw aluminum and can be polished, if the cream remains white then it is anodized.

[AyoLane]

how about replacing them with the new window? is that possible to do? without to much trouble?

[Ian G.]

Originally Posted by AyoLane

how about replacing them with the new window? is that possible to do? without to much trouble?

No benefit to replacing the windows, the only reason we polish the aluminum is for looks, that "cool factor"
It is almost impossible to find raw aluminum windows today, all the new windows are painted I replaced my door window on my Boler with a new one, all that was available was black which did not go with the rest of the windows so I ended up sanding all the black finish off so the base aluminum could be polished.

[sharon_b]

maybe try 000 steel wool?

[AyoLane]

ok I see I have a 1981 with the square windows, old school. Can the newer one replace the older ones. I am hoping to do it in the future

[Ian G.]

Originally Posted by sharon_b

maybe try 000 steel wool?

Steel wool is NOT polishing, it is finely scratching the surface.
The original mill finish aluminum under a microscope actually has a surface that looks like small hairs, each of these hairs increase the exposed surface area and will oxidize causing the dull finish. When you use a power polisher with the correct cutting compound you actually remove these hairs making the surface glass smooth, this reduces the surface area and the reflection actually comes from the aluminum surface. Because the polished surface has less surface area it is less prone to oxidation and a simple wipe will maintain the surface.

Chemical polishes like Mothers will dissolve or actually convert the oxidation and remove it but the surface area remains the same which means it will oxidize faster and be harder to maintain. Using scotch pads, steel wool or coarse abrasive pads leaves a uniform textured surface made up of small scratches in the same direction which, although looking good, will not directly reflect light, also the surface area is greater and therefore will oxidize faster.

I polished my aluminum 2 years ago, it still looks as shiney as the day I polished it.