[bdepedro]

I had a small radiator leak that sprayed antifreeze on my alum valve covers that I've tried to remove without luck. I have tried Mothers, Meguirs, NeverDull, and many other metal polishes. I've used the powerball, polishing wheels on my dremel, even 0000 steel wool. Anybody have any suggestions other than replacing them? Thanks for any advice!

[Nicoleb3x3]

I have the same issue....I've tried everything too
my next step is to try 1000 and 1500 sand paper..if needed go back down to 800 and back up again

[bdepedro]

That might be a possibility as I'm sure the antifreeze is INTO the alum which is why it's so hard to get off. If that literally sands the alum down to the level of the stain and removes it then using polishing paste to re-polish it might work.

I used my dremel again last night with some new polish someone recommended and it is better but still not gone.

[Nicoleb3x3]

used my technique on my radiator and overflow today...worked good! the 1500 will take the spots off with some patience...I then re-polished with mothers-

The 1500 did leave super fine scratches, but I feel that was better than the spots- plus I figured I can go back over it with 2000 later.

[MustangLX-5.0]

Aluminum is the easiest metal to work with I find. Mineral stains and other difficult chemical stains can be a pain to remove unless you have a few minutes with some sandpaper and polish. What I use, depending on how bad the stain is (eg.. excessive oxidizing from purple degreaser ).. for that I would start with 800 grit untill I barely see a spot. then move to 1000 for just a minute or two, then 1500, then 2000. With the 2000, I keep sanding until the sandpaper gets a bit clogged with metal particles. I then lighten the hand pressure and go over it with the clogged (NON -Wet) sandpaper. 2000 grit sandpaper worn down a bit and clogged with aluminum particles turns it into an almost 2500 - 3000 grit material which buffs the surface to an even deeper mirror finish. This must be done right otherwise you'll just re-deposit aluminum particles into the finish and haze it up. After this, I follow up with MAAS polishing creme. If you haven't heard of MAAS, check out MAAS . I have been using their metal polishing creme for 10 years. It's the best stuff out I think. Way better than Mothers Mag wheel polish or Meguires ...don't think Brasso will do any good, cause it wont. Take my word, I've been re-finishing metals for years.

Now you may not want to go with the 800 grit. That seems a bit rough for just antifreeze. Can you show me a picture of the coolant stain on the valve cover?

[Davis83]

hi, i have quite a bit of polished parts under the hood too, i found that california custom makes a product called purple metal polish which you can order from California Custom Products Inc. - Waxes & Polishes for Automotive Finishes and it works on aluminum, brass, copper , chrome, silver, stainless, and it removes blueing from pipes and headers as well. plus there is also a product called wenol which is awesome as well. everything on my engine has been done by hand by my roommate and he does the work for himself as well and his car constant show winner, pic below. anywho good luck.

[4G-KDMP]

A buffing wheel on and electric drill with Tripoli compound followed by White rouge compound = no sanding required and anti freeze stain gone