Refinishing alternator and AC compressor
Thread Starter
Melting Slicks
Joined: Aug 2000
Posts: 2,388
Likes: 42
From: Murrysville PA
Refinishing alternator and AC compressor
I just picked up a 96GS with 3300 miles. The alternator, AC compressor and ECM aluminum are showing some darkening and some oxide formation. I have another 96GS with 12,000 miles and the engine literally looks showroom new. I'll update this post later with some pictures. Looking for some tips and tricks to clean these items up. Trying to avoid removing the AC compressor to avoid re-charging.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
The best alum cleaners I know of are Mothers Mag & Aluminum polish and Never Dull wad polish. (The later is cotton-impregnated "wadding"). If you get a 4" cotton buffing wheel and put it in a drill, you can work wonders...using the Mother's. The cotton wad helps in places that are small, tight, grooved, etc...
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
It's pretty hard to use an aluminum polish on cast aluminum...and on the other stuff, it takes forever trying to get in all the nooks, crannies.
Aluminum brightener (doesn't really matter the brand), works in about 30 seconds.
Aluminum brightener (doesn't really matter the brand), works in about 30 seconds.
Oil Producer
Joined: Apr 2014
Posts: 9,375
Likes: 2,737
when the aluminum / pot metal (note, not pure aluminum) look all mottled like that, the only thing i have found that smooths it out, is the aluminum cleaner/brightner. THAT SAID, on the potmetal, it never comes out “bright”. Aluminum, such as intake manifolds, plenums, runners (tpi) all come out bright because they are pure aluminum.
I dont even know if the enclosures around say an alternator are aluminum really. ive seen them referred to as pot metal. not sure what what that means but perhaps they toss all sorts of cheaper alloys into a pot and melt it up. BUT the aluminum brightner will work to smooth out the blotches. in effect, its slowly etching away the surface later getting to fresh layers (we are talking at a molecular compound level here) and so it does restore the original, homogeneous finish.
BUT, i have also distinctly noticed that if left too long, similar to other weak acids like vinegar, it will cause flash rusting on steel components such as faster heads, and im sure inside alternators too.
After the cleaning is done, i now rinse bigtime.
I dont even know if the enclosures around say an alternator are aluminum really. ive seen them referred to as pot metal. not sure what what that means but perhaps they toss all sorts of cheaper alloys into a pot and melt it up. BUT the aluminum brightner will work to smooth out the blotches. in effect, its slowly etching away the surface later getting to fresh layers (we are talking at a molecular compound level here) and so it does restore the original, homogeneous finish.
BUT, i have also distinctly noticed that if left too long, similar to other weak acids like vinegar, it will cause flash rusting on steel components such as faster heads, and im sure inside alternators too.
After the cleaning is done, i now rinse bigtime.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski