fire bluing screw heads

Discussion in 'Gunsmithing Forum' started by dragonsmith, Aug 22, 2010.

  1. dragonsmith

    dragonsmith New Member

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    i have been trying to fire blue some screw heads, while i have had success with getting them very dark that is not my intention. I want to get that brilliant blue. i don't know if i am over heating them or perhaps i am not heating them enough. Any advice on the matter would be appreciated.
     
  2. shootingmad

    shootingmad New Member

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    G'day mate.
    Try heating them to a dull cherry red. When i say dull i mean only just red, need to hold them in the shade to see the red. Hope this helps you achieve the result. :D
     

  3. masterPsmith

    masterPsmith New Member

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    Heat slowly to a beep blue, then quickly quench in oil. If you go past blue when heating, quench and start again..

    Jim..........
     
  4. BillM

    BillM Active Member Supporter

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    You are getting them too hot. For that bright fire blue, polish to a mirror
    finish, and heat carefully. You are only going a little past 500° F. It
    comes on FAST if you are trying to use a torch.

    Some toaster ovens will do it, or a good heat gun. I used to just toss the screws on top of a wood stove and stoke up the fire a bit. When
    they get to the right color quench them quickly.

    Color chart here: Blue Blade Steel spring - steel, hardened and tempered steel, annealed
     
  5. c3shooter

    c3shooter Administrator Staff Member

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    Agree. Polish head, try holding the shank in a pair of needle nose, and heat the shank, watching the head- small parts heat REALLY fast. When you are ALMOST there, get ready to drop into a small cup of oil. Have used 30 W motor oil, linseed oil- but never tried olive oil (maybe for a Carcano? :rolleyes:)
     
  6. danf_fl

    danf_fl Retired Supporter

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    You may want to consider wrapping your needle nose with a wet rag and let the wet rag act as a heat sink. The grip can get a little warm.

    Harbor Freight has some long handled needle nose pliers that can help (and they are cheap enough that you can dispose of them after changing their temper)
     
  7. dragonsmith

    dragonsmith New Member

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    i thank you for your reply someone said i should see a straw color and then wait for it to turn blue but it doesn't all it does is get red. i have also quenching in linseed oil as i am told it offers protective properties, i will try again and try to heat it slower if no luck i will buy some nitrate blue from brownells and do it that way
     
  8. freefall

    freefall New Member

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    For knife blades I like peanut oil for quenching. It's very light and transfers heat quickly.
     
  9. Fisherking

    Fisherking New Member

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    for flat springs I have polished them and then I put them on the burrner of the stove ( electric). when they hit the right colour I quench in a sutable oil.
    Dont put the burrner on max just till you can reach the right temp.
    F.K.