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Thread: Removing deep scratches from aluminium?

  1. #1
    Little engine that could. itsnotagsr's Avatar
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    Removing deep scratches from aluminium?

    I have an aluminium petrol tank on my bike. Unfortunately it has a couple of deep scratches in it. Is there any way of "sanding" this back to remove the scratches? Simple polishing won't work.
    "If you can make black marks on a straight from the time you turn out of a corner until the braking point of the next turn, then you have enough horsepower." - Mark Donahue Penske Porsche 917

    "In Japan we no give fark for Subaru" - Trust Japan Technical Director
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  2. #2
    Carby Row Tree luvr edo's Avatar
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    yes...use a flapper wheel...then go finer & finer with sandpaper until its all gone, then polish with autosol or similar.

    It will probably take ages!
    Last edited by edo; 08-04-10 at 03:42 PM.

  3. #3
    Little engine that could. itsnotagsr's Avatar
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    Cheers. Might have to look into it.
    "If you can make black marks on a straight from the time you turn out of a corner until the braking point of the next turn, then you have enough horsepower." - Mark Donahue Penske Porsche 917

    "In Japan we no give fark for Subaru" - Trust Japan Technical Director
    (TM - AVENGE)

    "You can never have enough power. I remember when we had Group B cars... THEN we had enough power!"
    Juha Kankkunen - Rally of Argentina '02

  4. #4
    Carby Row Tree luvr edo's Avatar
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    Get a big one of these & work over a big area so you dont get a step. I assume it will stay polished & not get painted? Also assuming the scratches are on a bit which is curved in at least one direction, not a nice easy flat bit that you could sand back really easily using an orbital sander or something.


  5. #5
    Fondles
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    How deep are the scratches and how thick is the tank ?

  6. #6
    Little engine that could. itsnotagsr's Avatar
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    Thanks again edo. Yes will remain unpainted.

    Fondles - the scratches are only a mm or so deep. Its just too deep to just buff out. The tank is pretty thick. Its a custom jap style tank.
    "If you can make black marks on a straight from the time you turn out of a corner until the braking point of the next turn, then you have enough horsepower." - Mark Donahue Penske Porsche 917

    "In Japan we no give fark for Subaru" - Trust Japan Technical Director
    (TM - AVENGE)

    "You can never have enough power. I remember when we had Group B cars... THEN we had enough power!"
    Juha Kankkunen - Rally of Argentina '02

  7. #7
    Meh Billzilla's Avatar
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    So it really will buff out?
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  8. #8
    m o d e r a t o r Greg Rust's Avatar
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    ^^hehe let's hope so in this case, will be a first.
    xw Falcon 351 3/4 race cam

  9. #9
    TOKEN AUSSIE BOGAN tut's Avatar
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    scratches should be removed from the skin as soon as possible. The preferred method for scratch removal is by blending the scratch out. Scratches are starting points for corrosion.
    If scratches in clad aluminium are to be removed, it is necessary to examine wether the scratches have gone through the cladding
    if you want i can give you the test for this, too..
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    Quote Originally Posted by tim510 View Post
    More rabbit less turtle!

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  10. #10
    Surf's Up! bigmuz's Avatar
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    http://catalogue.3m.eu/en_GB/GB-ASD/...ing_Disc~SC-DB

    You need to find someone who welds and finishes aluminium and get them to use a series of surface conditioning discs to remove the scratch and then finish it ready for polishing. Flap wheels are terrible cause they load up. Sandpaper scratches it and takes heaps of finishing to get rid of.

    Scotch brite by hand is the way to finish it to a brushed look if that is what you are after.
    Quote Originally Posted by brasher View Post
    put ya stackhat on mate and back in your cage.

  11. #11
    Carby Row Tree luvr edo's Avatar
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    I took out heaps of scratches on various bits of TRX just as I described...worked a treat...

    If I had of thought of those scotch brite wheels I might have used them...but seeing as though I had the flapper wheels I probably wouldnt have bothered going out to get the scotch brite ones due to being a slack arse.
    Last edited by edo; 09-04-10 at 10:02 AM.

  12. #12
    Little engine that could. itsnotagsr's Avatar
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    Will take a picture during the weekend so that you guys can get a better idea of what I'm talking about.
    "If you can make black marks on a straight from the time you turn out of a corner until the braking point of the next turn, then you have enough horsepower." - Mark Donahue Penske Porsche 917

    "In Japan we no give fark for Subaru" - Trust Japan Technical Director
    (TM - AVENGE)

    "You can never have enough power. I remember when we had Group B cars... THEN we had enough power!"
    Juha Kankkunen - Rally of Argentina '02

  13. #13
    ...... marcus_h's Avatar
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    Slightly off topic.

    How do I get my alloy bullbar looking all shiny? Ive tried autosol but it doesnt seem to get it mirror and without a buffer is a pain in the arse. Any other products out there?

  14. #14
    Registered User RX-20B's Avatar
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    Wet and dry sand paper, 180 grit, 240 grit and 400 grit.

    Use the right buffing wheels and polishing compounds on a good bench grinder.
    I JUST SHARPENED A PENCIL IN MY BUM AND NOW I NEED A BANDAID

  15. #15
    Surf's Up! bigmuz's Avatar
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    Quote Originally Posted by marcus_h View Post
    Slightly off topic.

    How do I get my alloy bullbar looking all shiny? Ive tried autosol but it doesnt seem to get it mirror and without a buffer is a pain in the arse. Any other products out there?
    Alibrite.

    http://www.septone.com.au/detail.asp...395&page_num=9

    Edo- well done. I'm sorry I trod on your toes but generic abrasives aren't great on on ferrous metals. Well done that your flap wheels worked for you.
    Quote Originally Posted by brasher View Post
    put ya stackhat on mate and back in your cage.

  16. #16
    ...... marcus_h's Avatar
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    Cheers i'll give it a go

  17. #17
    Ready... Take aim... oldcorollas's Avatar
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    why not fill it in instead? might be better to add a mm depth of filler, then to remove a mm from a large area of tank...
    "I'm a retarded Doctor, not a retarded Mechanic"

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