Advertise on Bikeforums.net



User Tag List

Results 1 to 14 of 14
  1. #1
    Senior Member
    Join Date
    Jul 2007
    Location
    Minneapolis, MN
    My Bikes
    '86 Trek Elance 400; '83 Trek 520; 90s Specialized Crossroads
    Posts
    231
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Indoor Rust Removal...Oxalic Acid?

    I'm working on a couple bikes this winter and would like to do rust removal. Traditionally, I put the frame in a weak oxalic acid bath, outside. Now, it is almost January in Minneapolis and I don't think that'll work. I'm very hesitant to do the weak bath indoors as everything says to have ventilation, which I don't really have much of in the basement. Is this a concern with a very weak bath? If so, any other ideas about what would work inside? I'd like to do some sort of bath if possible as that is very much easier than tackling each rust spot individually. Thanks.

  2. #2
    S'Cruzer pierce's Avatar
    Join Date
    Jun 2010
    Location
    122W 37N
    My Bikes
    too many
    Posts
    2,292
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    the dust from the powder pure oxalic acid is quite hazardous to breath, but once mixed, its fairly dilute (1/8 cup per gallon of water), so I wouldn't think the fumes would be /too/ bad. of COURSE keep it way the heck away from any chlorine products. wear chemical grade rubber gloves, a splash shield for your face, etc etc.

  3. #3
    S'Cruzer pierce's Avatar
    Join Date
    Jun 2010
    Location
    122W 37N
    My Bikes
    too many
    Posts
    2,292
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    can anyone here who's used oxalic acid on bike parts chime in? I've got an old all campy 1974-5 Motobecane Grand Record... all the chrome bits on the old campy parts and frame bindings are rusty, and I'd love to make them shiny again... what treatment would you put on this sort of thing AFTER you've done the oxalic bath and rinse so it doesn't get rusty again ?




    also, do I need to remove aluminum bits, or is alloy OK in the oxalic bath?

  4. #4
    Junior Member
    Join Date
    Sep 2012
    Posts
    11
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    This product works well: http://www.evapo-rust.com/

  5. #5
    Senior Member rydabent's Avatar
    Join Date
    Apr 2010
    Location
    Lincoln Ne
    My Bikes
    RANS Stratus TerraTrike Cruiser
    Posts
    4,155
    Mentioned
    5 Post(s)
    Tagged
    0 Thread(s)
    A cheap bottle of CLR would probably do the job too.

  6. #6
    DRF aka Thrifty Bill wrk101's Avatar
    Join Date
    Jan 2008
    Location
    The NC Mountains
    My Bikes
    Too many to list, all vintage
    Posts
    18,868
    Mentioned
    71 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by pierce View Post
    can anyone here who's used oxalic acid on bike parts chime in? I've got an old all campy 1974-5 Motobecane Grand Record... all the chrome bits on the old campy parts and frame bindings are rusty, and I'd love to make them shiny again... what treatment would you put on this sort of thing AFTER you've done the oxalic bath and rinse so it doesn't get rusty again


    also, do I need to remove aluminum bits, or is alloy OK in the oxalic bath?
    There are at least 500 threads on Oxalic Acid already, and yes, you need to remove anything that is aluminum. OA also attacks zinc coated spokes.

    Try doing a complete frameset, say 30 to 40 gallons of solution, with evap-o-rust. Lets see, Evap-o-rust is $30 a gallon. Becomes cost prohibitive on larger jobs. Meanwhile, similar OA cost in a 30 gallon bath is about $3 if you buy OA in quantities, $20 if not. On small parts, I reuse the same solution for several months, treating parts at least weekly.

    I do my OA treatment indoors in the winter, in the basement. Smaller jobs I just have a container in the workshop.
    Last edited by wrk101; 12-24-12 at 08:56 AM.

  7. #7
    S'Cruzer pierce's Avatar
    Join Date
    Jun 2010
    Location
    122W 37N
    My Bikes
    too many
    Posts
    2,292
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    well, all the chrome bits on my old campy bike wouldn't take more than 2" in the bottom of a coffee can, I suspect. I'm pretty sure some of the bits have alloy stuff thats swaged on and not diassembable, so I'll likely go with evaporust if I ever undertake this project.

    parts like that headset, and the shifter clamp, in that picture above... once I get all the rust off, what would you do to keep the bare metal from rusting up again where the chrome is gone ? just wipe them down in WD40 and keep them all a little oily? or some sort of wax? silver spray paint? send them off to be re-chromed?

  8. #8
    Senior Member Spld cyclist's Avatar
    Join Date
    Nov 2011
    Location
    Springfield, MA
    My Bikes
    2012 Motobecane Fantom CXX, 2012 Motobecane Fantom CX, 1997 Bianchi Nyala, 200? Burley Rock 'n Roll
    Posts
    976
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    You can use a vinegar solution for rust removal, as well as citric acid solution. Neither will cause hazardous fumes. I'm a fan of evaporust, but as someone said above, it's not cost-effective if you need to soak something large.

  9. #9
    S'Cruzer pierce's Avatar
    Join Date
    Jun 2010
    Location
    122W 37N
    My Bikes
    too many
    Posts
    2,292
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I don't quite get the chemistry behind using an acid... acids oxidize metals. iron oxide is rust.

  10. #10
    Senior Member
    Join Date
    Oct 2009
    Location
    England, currently dividing my time between university in Guildford and home just outside Reading
    My Bikes
    Too many to list here!
    Posts
    1,896
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by pierce View Post
    I don't quite get the chemistry behind using an acid... acids oxidize metals. iron oxide is rust.
    If my half-remembered chemistry is correct, in the right conditions, some acids can also act as reducing agents.

  11. #11
    DRF aka Thrifty Bill wrk101's Avatar
    Join Date
    Jan 2008
    Location
    The NC Mountains
    My Bikes
    Too many to list, all vintage
    Posts
    18,868
    Mentioned
    71 Post(s)
    Tagged
    1 Thread(s)
    Ferric oxide (rust) reacts with oxalic acid, forming ferric oxalate. It is not reacting with the steel, it reacts with the rust.

    Other acids will also react with the rust, they are just more expensive and less effective. The choice is yours.


    Good read from the BMX forum:

    http://www.vintagebmx.com/community/...wtopic=4004702

  12. #12
    S'Cruzer pierce's Avatar
    Join Date
    Jun 2010
    Location
    122W 37N
    My Bikes
    too many
    Posts
    2,292
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    so, my other question... after cleaning up badly rusted formerly chromed bits like that headset, shifter clamp, on my Motobecane... what do you suggest for protection on the now bare steel exposed between whatever chrome is left to keep it from getting all rusty again ?

  13. #13
    Senior Member
    Join Date
    Nov 2005
    Posts
    1,593
    Mentioned
    4 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by pierce View Post
    the dust from the powder pure oxalic acid is quite hazardous to breath, but once mixed, its fairly dilute (1/8 cup per gallon of water), so I wouldn't think the fumes would be /too/ bad. of COURSE keep it way the heck away from any chlorine products. wear chemical grade rubber gloves, a splash shield for your face, etc etc.
    1/8 cup per gallon of water? Seems pretty excessive given .02 % is around 1/4 cup in a eighty gallon kiddie pool and works just fine in around 30 hours @ 70-90 degrees.

  14. #14
    S'Cruzer pierce's Avatar
    Join Date
    Jun 2010
    Location
    122W 37N
    My Bikes
    too many
    Posts
    2,292
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    ah, that 1/8 cup per gallon was what I read on several how-tos.

    sigh, won't get to 70/80 degrees here until next summer, and then only during the days (pacific ocean cools things off to the 50s the minute the sun drops). we keep indoors at 66-67F and the garage is completely unheated and drafty.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •