Advertise on Bikeforums.net



User Tag List

Results 1 to 23 of 23
  1. #1
    la vache fantôme phantomcow2's Avatar
    Join Date
    Aug 2004
    Location
    NH
    Posts
    6,266
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Anybody here passivated stainless steel?

    I am told that in order to passivate stainless steel, I'll need a strong concentration of Citric acid, and NaOH.
    Well I got both of these from work.

    I was wondering if anybody here has been able to passivate stainless steel components on their own. If so, was it a success? My stainless steel tubes are going to be in a potentially corrosive environment 24/7, so I want the best very best.
    C://dos
    C://dos.run
    run.dos.run

  2. #2
    Banned. timmyquest's Avatar
    Join Date
    May 2005
    Location
    Woodstock
    Posts
    5,761
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I'm beginning to wonder if answering your questions is supporting terrorism.

  3. #3
    Gears? CliftonGK1's Avatar
    Join Date
    Jul 2006
    Location
    Philadelphia, PA
    My Bikes
    '08 Surly Cross-Check, 2011 Redline Conquest Pro, 2012 Spesh FSR Comp EVO, 2009 Spesh Singlecross, 2011 RM Flow1
    Posts
    11,322
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Never tried it, but here's a good article on the theory behind passivation, including 3 methods and their various applications, and a well-written how-to.

    http://www.mmsonline.com/articles/100304.html
    "I feel like my world was classier before I found cyclocross."
    - Mandi M.

  4. #4
    (((Fully Awake))) Serendipper's Avatar
    Join Date
    Oct 2005
    Location
    ~Serenading with sensous soliloquies whilst singing supple sentences that are simultaneously suppling my sonnets with serenity serendipitously.~ -Serendipper
    My Bikes
    Guerciotti Pista-Giant Carbon-Bridgestone300- Batavus Type Champion Road Bike, Specialized Hardrock Commuter, On-One The Gimp (SS Rigid MTB/hit by a truck)- Raleigh Sports 3-speed,Gatsby Scorcher, comming soon...The Penny Farthing Highwheel!
    Posts
    5,598
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    ex-lax

  5. #5
    ****** squegeeboo's Avatar
    Join Date
    Dec 2006
    Location
    Rochester, NY
    My Bikes
    Specalized Tri-Cross
    Posts
    906
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Dude, you so need a second job, or a third job, or a woman, or something.
    In the words of Einstein
    "And now I think I'll take a bath"

  6. #6
    Gears? CliftonGK1's Avatar
    Join Date
    Jul 2006
    Location
    Philadelphia, PA
    My Bikes
    '08 Surly Cross-Check, 2011 Redline Conquest Pro, 2012 Spesh FSR Comp EVO, 2009 Spesh Singlecross, 2011 RM Flow1
    Posts
    11,322
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Serendipper View Post
    ex-lax
    It took me a little while to get it.

    Um... ew.
    "I feel like my world was classier before I found cyclocross."
    - Mandi M.

  7. #7
    Administrator Allen's Avatar
    Join Date
    Sep 2005
    Location
    Atomic batteries to power; turbines to speed
    My Bikes
    Salsa La Raza, Panasonic Electric, Bria, Bamboo touring, Bamboo cargo
    Posts
    4,701
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Gold plate it? Gold is about as non-reactive as it gets.
    You have asked about electroplating in the past.

  8. #8
    You Know!? For Kids! jsharr's Avatar
    Join Date
    Apr 2005
    Location
    Just NW of Richardson Bike Mart
    My Bikes
    '05 Trek 1200 / '90 Trek 8000 / '? Falcon Europa
    Posts
    6,083
    Mentioned
    12 Post(s)
    Tagged
    3 Thread(s)
    Quote Originally Posted by AllenG View Post
    Gold plate it? Gold is about as non-reactive as it gets.
    You have asked about everything known to man or beast in the past.
    fixed
    Are you a registered member? Why not? Click here to register. It's free and only takes 27 seconds! Help out the forums, abide by our community guidelines.
    Quote Originally Posted by colorider View Post
    Phobias are for irrational fears. Fear of junk ripping badgers is perfectly rational. Those things are nasty.

  9. #9
    370H-SSV-0773H linux_author's Avatar
    Join Date
    May 2005
    Location
    Penniless Park, Fla.
    My Bikes
    Merlin Fortius, Specialized Crossroads & Rockhopper, Serotta Fierte, Pedal Force RS2
    Posts
    2,760
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    OffTopic: mr. b, are you MERTON's smarter brother?

    :-)

    OnTopic: interesting question... i assume you've figured out the cleaning step? and you're sure about the sodium hydroxide solution? what about the sodium dichromate?

  10. #10
    la vache fantôme phantomcow2's Avatar
    Join Date
    Aug 2004
    Location
    NH
    Posts
    6,266
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    The cleaning step is acetone. I was impatient after I machined my delrin spacer last night after work, so I went ahead and pressed in dirty tubes into there. BUt, now I need to take it apart and do it right .
    C://dos
    C://dos.run
    run.dos.run

  11. #11
    Videre non videri
    Join Date
    Sep 2004
    Location
    Gothenburg, Sweden
    My Bikes
    1 road bike (simple, light), 1 TT bike (could be more aero, could be lighter), 1 all-weather commuter and winter bike, 1 Monark 828E ergometer indoor bike
    Posts
    3,202
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Oh, pleeeeeeeeezzzzeeeee tell us what you're building!!! Is it a doomsday device?

  12. #12
    . botto's Avatar
    Join Date
    Jan 2006
    Posts
    40,335
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by phantomcow2 View Post
    I am told that in order to passivate stainless steel, I'll need a strong concentration of Citric acid, and NaOH.
    Well I got both of these from work.

    I was wondering if anybody here has been able to passivate stainless steel components on their own. If so, was it a success? My stainless steel tubes are going to be in a potentially corrosive environment 24/7, so I want the best very best.
    do you ever ask a question that a non-nerd would be able to aswer?

  13. #13
    la vache fantôme phantomcow2's Avatar
    Join Date
    Aug 2004
    Location
    NH
    Posts
    6,266
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by CdCf View Post
    Oh, pleeeeeeeeezzzzeeeee tell us what you're building!!! Is it a doomsday device?
    I'll tell you when it's done. I'll take a picture first and let people guess.
    C://dos
    C://dos.run
    run.dos.run

  14. #14
    la vache fantôme phantomcow2's Avatar
    Join Date
    Aug 2004
    Location
    NH
    Posts
    6,266
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by botto View Post
    do you ever ask a question that a non-nerd would be able to aswer?
    Why do you ask questions that you can answer yourself?
    C://dos
    C://dos.run
    run.dos.run

  15. #15
    Banned
    Join Date
    Aug 2004
    Location
    Riverview, Florida
    My Bikes
    Trek 4900
    Posts
    1,137
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    as soon as I read the thread title, I knew in my mind that the ptcow2 was at something new in his labratory.

  16. #16
    . botto's Avatar
    Join Date
    Jan 2006
    Posts
    40,335
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by phantomcow2 View Post
    Why do you ask questions that you can answer yourself?
    i have many lawyers in the family.

  17. #17
    Giving you the business. Cypress's Avatar
    Join Date
    Jan 2006
    Location
    Corvallis, Oregon
    My Bikes
    Ridley Noah, Giant Trinity Advanced, Specialized Crux
    Posts
    4,441
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Someone bet me $5 that I couldn't swallow a quarter.

    The x-ray still sits on my wall.
    Quote Originally Posted by Moderator
    Dear Cypress,

    You have received an infraction at Bike Forums.

  18. #18
    Banned. timmyquest's Avatar
    Join Date
    May 2005
    Location
    Woodstock
    Posts
    5,761
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Cypress View Post
    Someone bet me $5 that I couldn't swallow a quarter.

    The x-ray still sits on my wall.
    After a night of partying it up, a friend of mine puked all over the floor...which sucked. But the $.75 we found in the puke made it worth while.

  19. #19
    coffeeeeee p4nh4ndle's Avatar
    Join Date
    Aug 2007
    Location
    somewhere in Pennsyl-tucky
    My Bikes
    all that I ride
    Posts
    238
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    is passivating the same as pickling. I think they use much stronger acids for that (nitric or flouric).
    If memory serves me correctly...


    which it often doesn't

  20. #20
    No Rocket Surgeon eubi's Avatar
    Join Date
    Jan 2005
    Location
    Corona and S. El Monte, CA
    My Bikes
    Cannondale D600, Dahon Speed T7
    Posts
    1,648
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by botto View Post
    do you ever ask a question that a non-nerd would be able to aswer?
    *sigh*

    OK, here goes...

    The latest material specification controlling passivation is AMS 2700. This replaces QQ-P-35, which has been around forever. There are two methods and eight types of passivation described. In addition, since my company is in CA, we have our OWN passivation spec, which uses weaker concentrations of Nitric for a longer period.

    You want Method 2, using citric acid, so we go to Paragraph 3.1.4 (hahaha)... here goes...

    Parts shall be immersed in an aqueous solution of 4 to 10 weight percent citric acid, with additional wetting agents and inhibitors as applicable.

    Temperature: Bath temperature shall be 70 to 160 ºF with immersion time of not less than 4 minutes for baths operating over 140ºF, not less than 10 minutes for baths operating in the 120 to 140ºF range, or not less than 20 minutes for baths operating below 120ºF.

    Post treatment: When a post treatment is specified, after rinsing, parts made from ferritic, martensitic, and precipitation hardened steels shall be immersed in a solution contining 4 to 6% by weight of sodium dichromoate dihydrate at 140 to 160ºF for one hours, rinsed and dried.


    The NaOH is not part of the passivation process, I'm guessing it's to neutralize the citric acid before disposal. NaOH is a strong base, and can be very dangerous, so be very careful with it.

    However, this Wiki article says citric acid is not hazardous to dispose of, as is nitric.

    http://en.wikipedia.org/wiki/Citric_acid

    But hey, it's Wikipedia! Just the same, be careful what you dump down the drain in NH.

    Have fun.
    Fewer Cars, more handlebars!

  21. #21
    la vache fantôme phantomcow2's Avatar
    Join Date
    Aug 2004
    Location
    NH
    Posts
    6,266
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    ALl done . Did it last night. I have no idea if it works, but my tubes are shiny clean.
    C://dos
    C://dos.run
    run.dos.run

  22. #22
    No Rocket Surgeon eubi's Avatar
    Join Date
    Jan 2005
    Location
    Corona and S. El Monte, CA
    My Bikes
    Cannondale D600, Dahon Speed T7
    Posts
    1,648
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by phantomcow2 View Post
    ALl done . Did it last night. I have no idea if it works, but my tubes are shiny clean.
    Oh...

    Well, it's a bit late, but here's the MSDS too...

    Glad it worked!

    http://www.chemistrystore.com/Chemic...RIC%20ACID.pdf
    Fewer Cars, more handlebars!

  23. #23
    la vache fantôme phantomcow2's Avatar
    Join Date
    Aug 2004
    Location
    NH
    Posts
    6,266
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Oh, I've already got the citric acid MSDS. We order it at work sometimes.
    I followed hte instructions on this site:
    http://www.cartech.com/machining_zone/citric_pass.html

    This was 304, so I heated my water to 150 degrees and let it sit for 30 minutes. We're getting closer to success here! Just one more package and some quality sit-down time.
    C://dos
    C://dos.run
    run.dos.run

Posting Permissions

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