How to Remove Heat Stains on Engine?

Discussion in 'GS Boxers' started by DetourJournal, Jan 25, 2013.

  1. PNWRR

    PNWRR not fragile

    Joined:
    Apr 29, 2011
    Oddometer:
    1,006
    rattle can it flat black :wink:

    :freaky
    #41
  2. vintagerider

    vintagerider Long timer

    Joined:
    Nov 20, 2005
    Oddometer:
    1,976
    Location:
    the west
    There have been some great threads on re-finishing mag alloy covers. Conlusion was do not remove the chromate? base coating. Just lightly sand and re-paint. If you have abrasions then that is almost not worth trying to repair. . A few places claim that they can sand then powder coat. If you can find 1100 Al alloy covers then they are easier to refinish.

    I'm glad that you didn't catch fire. If she is running now then just ride and be happy.
    #42
  3. H96669

    H96669 A proud pragmatist.

    Joined:
    Nov 20, 2009
    Oddometer:
    4,849
    Location:
    Hiding off Hwy 6, B.C.
    Yes been looking into that refinishing magnesium. Leave the chromate there or add some more if missing in spots. It is a very important step to the process otherwise good chance the paint will bubble.

    The powdercoating is eluding me, altough my friend has a proper setup we are weary. Flashpoint for magnesium is only 500F, may even warp at the 400F baking temp and looking at some that DIY it, good chances of bubbling. I'd need a piece of magnesium and different powders to do my own tests, won't be this year,already spent too many hours looking into that and getting info all over the place.

    Be very weary using any caustics even at low concentrations against Aluminium/Magnesium and anodizing. Google the warnings, don't believe everything.

    Don't know if you have the same coating as my K-bike magnesium covers, I'd assume so. Carb Cleaners will soften it, may not look like it has failed right away, may be a different story after a few heat/cold cycles.:eek1
    #43
  4. H96669

    H96669 A proud pragmatist.

    Joined:
    Nov 20, 2009
    Oddometer:
    4,849
    Location:
    Hiding off Hwy 6, B.C.
    Did a bit more checking today picking up BMW parts I had powdercoated. Looks like all of them already were from BMW. A coat of silver then a clear coat and that's what you may be removing with the yellow, the clearcoat. It tends to get yellow with age, heat and also in the case of the K-bikes.....gasoline.:eek1

    Altough my powdercoater is very good, he doesn't do that for a living. Did not have the right stripper, that would be B17, and used aircraft stripper. It did work but took many applications. Looks like I owe him a big favor now and he has learned not to quote before such jobs.

    "Powder 365" Silverado Silver with the right clear coat, I can doublecheck I think mine is lower gloss is very close to the BMW color. Saves getting lost in other sites with too many color choices and chips you can't see online. I took a gamble when ordering, paid off. Finding a powdercoater that does Magnesium well, another story. Maybe DIY for some of us but will take some studying first.
    #44