Topic: How to prevent polished bits oxidized almost instantly?

[davis96]

I recently got done rebuilding my 71 cb500 (again) in my garage. Part of the rebuild was to paint the motor and polish the usual bits (see before picture)... However within a day of getting the bike outside, (there may have been a mist of rain, but it has definitely been quite humid) the parts that I spent so many hours polishing look like sh!t.

I am aware that moisture causes oxidation on bare aluminum parts, and that (according to my forum research) I would have to shine the parts back up "every now and then"... but this is nuts. Anyone else experience this? What kind of coating should I apply to abate this kind of oxidation? Wax? Clear coat? I don't need a miracle, just something that will let my polished bits shine nicely for maybe a month before i have to hit em with the alum polish..

The engine after polishing/paint:





Now all my polished parts look like this or worse:

[scottly]

Mother's mag polish works for me...

[madmtnmotors]

Mother's mag polish works for me...

Followed by a coat of wax doesn't hurt either.

[dave500]

polished alloy is a labour of love.,over and over,thats why i dont bother with the fiddly bits.

[Markcb750]

I think what I see in the photos is residual pitting in the aluminum that reappears when the polish drys.  I found it was necessary to sand the surfaces to remove the pits, this involves removing several thousandths of an inch of metal. 

I use a orbital sander to remove the majority of the pitting, then wet hand sand in 200 grit increments to 1500 grit paper.

then white or red polishing compound depending on which one seems to work best on the metal I am polishing.  depends on the alloy I guess, white most of the time.

Just an occasional touch up with mothers or one pf the other mag wheel compounds is all  seems to  take.

[Cheffish]

Mother's mag polish works for me...

Some mothers on a towel will clean that right up. It's from the rain

[fastbroshi]

+1 on the Mother's.  It'll keep the polished bits looking nice for a varying amount of time.  If you ride more, it's going to need touching up more often obviously.

[davis96]

Thanks guys maybe I'll try mother's. I have no problem with labors of love or elbow grease, but I mean I haven't even ridden it once (unrelated engine issues). I guess I have to chalk it up to the super high humidity here, because even the polished stainless tach housing has not only oxidized, but is beginning to show signs of surface rust 

[Dave K]

Aluminum is easy, try keeping magnesium pretty!

[trueblue]

http://www.californiacustom.com/purple_metal_polish.html

I use California Gold, Purple metal polish.  It bends mother over and smacks its arse.  When I polished my bike, I started with 400 grit then 1200 then 2000 grit wet and dry.  Once I had lost almost all the skin off my fingers, I moved to a cotton buff with white wax, then cleaned with prepsol and applied the purple.  It brought it up like a mirror.  I give it a touch up when it starts looking a little dull, normally every 2-3 months, depending on how much rain we get.

[RSchaefer]

I polished all of my side covers and clear powder coated them.  I saw where another member on the forum had done this and I had purchased a powder coat system to do all the black parts so clear powder coated all of the polished side covers.

Valve Covers




Alternator Cover - I did the recessed HONDA in back powder.  Picture with powder before bake


and the gear #'s on the shifter cover

[madmtnmotors]

I polished all of my side covers and clear powder coated them.  I saw where another member on the forum had done this and I had purchased a powder coat system to do all the black parts so clear powder coated all of the polished side covers.

Aw, man, now you've gone and made me want to do the same! The only issue I could think of would be the adhesion to the polished surface. I thought the powder had similar durability issues as clear paint when applied to polished surfaces in that it would peel from such a smooth surface. Has anyone had experience with durability?

[RSchaefer]

Well I have not got her all together yet so I am not sure, obviously hoping for the best.  Like I said there was another member who had done his with apparently god results.  I used the Eastwood Powder and the clear cures at 350 degrees and its the kind of powder that molecularity links and cannot be re-coated, so I am thinking I should be fine.

[scottly]

I use California Gold, Purple metal polish.  It bends mother over and smacks its arse.

California Gold is made by Mothers.
My shifter cover was wet-sanded with 400, then 600 grit, then polished by hand with Mothers about a year ago. There is some road grime, but no oxidation. The horizontal line to the left of the shift shaft is a reflection of the kick-stand.