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How do i strip galvinizing?

Discussion in 'The Hokey Ass Message Board' started by Shaggy, Aug 13, 2011.

  1. Shaggy
    Joined: Mar 6, 2003
    Posts: 5,207

    from Sultan, WA

    Is there a 1/2 assed homemade process of stripping it? i cant get ungalvinized fasteners locally
  2. 23dragster
    Joined: Apr 22, 2011
    Posts: 264

    from U.S.

    Wire wheel maybe? (Try brass wheel first). Some galvanized stuff is pretty deep.

    (Another solution might be ordering a whole assortment of bolts online).

    (Or, what we like to do sometimes is buy a project car that no one wants for cheap, then strip all the hardware to use later on; on our own projects).
  3. american opel
    Joined: Dec 14, 2006
    Posts: 1,222

    american opel
    from ohio

    why do you want to take the galv.coating off?if you dont want galv.go to any home-depot,or lowes.they have any kind of bolt you want-need.
  4. 28chevrat
    Joined: Oct 11, 2005
    Posts: 322


    Die grinder and scotch britte pads .... but agree with above post ^^^^^^^^^^^

  5. Pasta
    Joined: Aug 16, 2010
    Posts: 65


    Prep & Etch acid sold at Home Depot in the paint dept. Takes it off in 20 minutes, however, don't use this on any critical fasteners as hydrogen embrittlement may occur, but it's great for non structural applications.
    Like the other guys said, just but grade 5 or 8 fasteners as needed.

  6. Villlage Idiot
    Joined: Dec 30, 2005
    Posts: 408

    Villlage Idiot

    We have material galvanized where I work (plumbling manufacturing) and it's a bitch to try and remove. It can be ground off if you have the patience. I don't know of a stripper out there that will cut it but that doesn't mean that there isn't one. If you do grind it or have a reason to weld a galvanized part make sure you wear the proper breathing aparatus. The dust from grinding it and the fumes from welding it will kill ya.
  7. mysteryman
    Joined: Apr 20, 2011
    Posts: 253

    from atlanta

    if you remove the coating there going to rust fast.if you want to paint them clean them off with vinegar before painting.
  8. Finnrodder
    Joined: Oct 18, 2009
    Posts: 2,965

    from Finland

  9. 28chevrat
    Joined: Oct 11, 2005
    Posts: 322


    Yeah that shit will kill ya!!
  10. ehdubya
    Joined: Aug 27, 2008
    Posts: 2,315


    I've yet to see any documented proof of that, it can give you 'welder's flu'.
  11. 28chevrat
    Joined: Oct 11, 2005
    Posts: 322


    Yeah i know but have you welded that shit it stinks and is nasty. I cant image its good for you. yeah I know its not documented and stuff but really?
  12. ehdubya
    Joined: Aug 27, 2008
    Posts: 2,315


    Galvanizing is hot dipped zinc but most decent grade bolts are electroplated and need to be heat treated within an hour of plating but don't know why or if it's required with the reverse.
    I've seen acid used when they were to be gun blued but don't know the type or why you'd want to either.
  13. ehdubya
    Joined: Aug 27, 2008
    Posts: 2,315


    I've welded the stuff day in and out (and will do most anything not to) and been around spraying where it starts to feel like tinfoil on dental fillings, had welders flu and researched it, so really :D
  14. Shaggy
    Joined: Mar 6, 2003
    Posts: 5,207

    from Sultan, WA

    It'll weld cleaner without it.... I need a bunch of threaded frame and body mount stuff for my model t....
  15. Royalshifter
    Joined: May 29, 2005
    Posts: 15,517

    from California

    Welding it or burning it....takes one wrong move for your lungs to lock up and the zinc go into your blood and before you know it St. Peters is drinking a beer with you......on second thought some might not think that is to bad?
  16. Willy301
    Joined: Nov 16, 2007
    Posts: 1,426


    I have to hunt for galv hardware when I need it, all the hardware here is Zinc coated.
  17. BillWallace
    Joined: May 6, 2011
    Posts: 132


    welding galvanized material should be avoided as it (the fumes) attack the liver & lungs. IF you do weld it drink a big glass of milk afterward as this minimizes the effects.
  18. VoodooTwin
    Joined: Jul 13, 2011
    Posts: 3,455

    from Noo Yawk

    I used galvanized electrical conduit (sliced and quartered) to weld up molded drip rails. I first grinded (or is it "ground"?) off the outer layer of galvanizing before welding it. Worked fine....I think.
    Joined: Jan 1, 2008
    Posts: 1,374

    from Bordertown

    Im thinking Lowes and the Depot also have raw steel bolts, also try an ACE or True Value...and yup on the welding galvanized...thats some bad stuff right there!!!
  20. supervert
    Joined: Mar 8, 2009
    Posts: 433


  21. Von Rigg Fink
    Joined: Jun 11, 2007
    Posts: 13,426

    Von Rigg Fink
    from Garage

    I used to be friends with 2 people who worked in a small shop that did nothing but weld, grind and work with galvanized steel parts.
    they are both was 67..the other was 32..same shop

    maybe its just a coincidence? why take that chance?

    Galvanized metal contains zinc, which becomes a toxic vapor when it is heated. Zinc gases can cause metal fume fever, which does permanent damage to your lungs. Although it usually resolves itself within 48 hours with no apparent permanent effects, metal fume fever can be fatal within hours of exposure. The effects of zinc vapor poisoning can continue for up to two weeks later, causing extreme fatigue, shortness of breath,blurred vision, muscle pain, nausea and . Complications include chemical pneumonia and death when zinc exposure is combined with exposure to other heavy metals such as cadmium oxide.
  22. flight75
    Joined: Nov 16, 2009
    Posts: 32


    I've worked in electrogalvanizing for 15 years and I'm still alive. The way we strip galvanizing is to use an inhibited sulfurice acid at around 10% concentration. Use caution when mixing the solution and don't breath the fumes. The reason you dont want to is zinc even in the most pure form contains 30-40 ppm of lead.
  23. TRIK3R
    Joined: Mar 19, 2011
    Posts: 49


    Brazing EMT together for airboat propeller guards for 25 years didnt help me any, I've had plenty bouts with welders flu, People cant understand why my left hand shakes, could be dain bramage, I have to have a few beers nowadays just to tig weld nicely. X2 On the prep/etch to strip the zinc.
  24. gearheadbill
    Joined: Oct 11, 2002
    Posts: 1,313


    Ditto this. No heat needed. Soak 'em in muratic acid (used to balance PH levels in swimming pools) for a day....clean as a whistle.
  25. moefuzz
    Joined: Jul 16, 2005
    Posts: 4,950


    If your problem is in welding through it.....

    I weld thru it everyday, nuts, bolts, grating, sheet steel etc.
    Don't breath the fumes and keep your head out of the path of the white stuff that comes off it and you'll be ok.
    If you are worried, wear a respirator or 3M style mask and work in a ventilated (not windy) area.

    Nuts and bolts are easy to weld thru.

    Attach the fastener and align then into the position you wish to weld them into.
    Hold them firmly in place by tightening them, whether permanent or temporary, attach a nut/bolt to the other side and snug it up.
    Using a regular old wire wheel on your hand held grinder and run around the area to be welded for a good few seconds.
    The wire brush does 2 things: The wire obviously scrapes the surface but more importantly it creates heat thru friction.
    Wire brush the galvanized long enough for it to build some heat at which point it will more easily remove the galvanized coating. This will take several seconds on each face of the fastener.
    -6 or 8 seconds on the average 1/2 bolt head should remove most of the coating.
    Whats left will have to be welded thru.

    TURN THE HEAT UP! (that means keeping the wire speed down also) A cold mig will barely adhere to clean steel and if it's too cold to adhere to regular steel then you aren't going to be able to burn the remaining zinc coating up on galvanized.
    If the wire speed is too fast then you are pushing cold clumps of barely warmed wire onto, on top of the metal and you won't actually weld anything.

    Practice on some scrap bolts.
    Turn the heat up enough so that you are pouring a nice hot puddle to both the fastener and the surrounding panel.
    Go Slow! Forward motion of your mig should be slow and sure, moving too fast will cause you to have a cold non adherent weld. Slow down and let the puddle fill.
    Whether you are welding regular steel or galvanized, you never want to out run your puddle, let it fill, let it build heat and let it adhere.

    As the puddle fills you will notice that at times, your puddle changes from a normal yellowish to a blueish glow.
    That is the galvanized burning out.

    Move slowly almost stopping when you see the blue color. Let the galvanized rise to the top.
    Your puddle will return to a nice yellow once you have burnt the zinc off at that particular point on the galvanized part.

    If you move too fast, the puddle turns excessively blue and the heat of the puddle cannot burn the zinc off which makes for an ugly crap filled weld as well as excessive porosity etc.

    And remember, practice turning the heat up on some extra fasteners Before you attack your project.

    -(you have to learn to weld before you can weld thru galvanized or restore a car).

    just my humble opinion


    Last edited: Aug 15, 2011
  26. mickeyc
    Joined: Jul 8, 2008
    Posts: 1,349


    I have removed galvanize from metal many times. If you are referring to bolts you would have to burn it of with a torch. Also be aware that bolts that are made for galvanizing use a different thread pitch than normal bolts (more coarse). If you ever try to install a non galv nut on a galv bolt you will see the difference right away. to remove galv from steel we use grinding blades or burn it off with a ox acetylene torch. I do this in prep for welding or to remove excessive build up on structural members before bolting and welding. Hot dip galv when properly applied forms a resilient bond with steel, and is not easy to remove. Also be aware that burning or grinding this material produces nasty fumes and smoke that
    when inhaled will make you feel like shit for several hours. Ask me how I know! Always use at least a dust mask or a particulate filter mask when causing air borne debris from galv.
  27. Shaggy
    Joined: Mar 6, 2003
    Posts: 5,207

    from Sultan, WA

    Oh ive done it, most of my welding other than frame stuff is O/A so heat hasnt been an issue, but i'd just rather strip it instead of having it come out as ugly as they do
  28. echnidna
    Joined: Aug 26, 2009
    Posts: 64

    from Australia

    Soak them in vinegar for a day or so, it's a lot safer than muriatic acid etc. Clean & easy.
    p.s. Don't use the vinegar on your fish and chips afterwards
  29. johnny bondo
    Joined: Aug 20, 2005
    Posts: 1,547

    johnny bondo
    from illinois

  30. flynbrian48
    Joined: Mar 10, 2008
    Posts: 7,348


    Why hasn't anybody asked why the OP is using hardware store galvanized fasteners, anyway? I was under the impression that stuff is not even grade #3. I get nut's and bolts from Tractor Supply in bulk, and use grade 8 for the importants stuff, grade 5 for non critical stuff like fender bolts and body fasteners.


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