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Thread: Hot Bluing

  1. #16
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    Quote Originally Posted by NedsHead View Post
    Hi Joe

    I used 5lb potassium hydroxide, 2.5lb potassium nitrate, 1gal distiller water (although some water did evaporate while bluing), the time was approximately 25 minutes and the temp hovered around 140 C, it climbed a little as the water evaporated.

    I switched out the sodium hydroxide in the formula for potassium hydroxide because I have some on hand and I doubt it makes any difference, if I were to scale up the process I would use sodium hydroxide because it's considerably cheaper than potassium hydroxide

    Cheers

    At 140 degrees Celsius is the solution actively boiling ? ie bubbling and spitting and splashing droplets ?

    Bill

  2. #17
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    Hi Bill, at that temperature it's simmering, with all the salts dissolved in the solution it doesn't "bump" like boiling water does at 100C but it does spit small droplets around where it's being heated and release tiny caustic particles into the air that sting when they settle on skin, it's a well ventilated, covered skin and goggles affair

  3. #18
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  4. #19
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    This would be a good way to make shop made tooling last longer .And look better .

    Michael

  5. #20
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    I finally got some Potassium Nitrate yesterday. It was a special order and I had to leave my ful name, address, phone and license number to get it.
    Seems nobody bothers to stock it anymore because of these requirements.
    I won't have a chance to try and blue anything for a week or so, but will post the results here when I do.
    Cheers, Joe
    again completely retired - more time to contemplate projects and spend more shed time....

  6. #21
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    I look forward to seeing your results Joe, it's pretty pathetic what you had to go through just to get it, lets hope counter terrorism don't swoop your house over a bag of potassium nitrate lol

  7. #22
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    Default Potassium Nitrate

    Quote Originally Posted by jhovel View Post
    I finally got some Potassium Nitrate yesterday. It was a special order and I had to leave my ful name, address, phone and license number to get it.
    Seems nobody bothers to stock it anymore because of these requirements.
    I won't have a chance to try and blue anything for a week or so, but will post the results here when I do.

    I've tried too and anywhere I go they just say "No cannot get it any more - people were doing scary things with it"

    When I was a kid we could get Kwikcure from the local supermarket which was then used to cure meat and was pottassium nitrate

    This mob might be worth a try - am off on holidays and will try when I get back.

    kno3 potassium nitrate australia

    Bill

  8. #23
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    15 bucks a kilo, ouch... How much did you end up paying for a bag Joe?

  9. #24
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    I paid $71.40 for 25kg.
    Happy to share, if someone else wants a couple of kg ($3 a kg + postage).
    Cheers, Joe
    again completely retired - more time to contemplate projects and spend more shed time....

  10. #25
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    Yes they are talking about ammonium nitrate as a fertilizer however potassium nitrate is even more dangerous .
    You want Sodium Nitrate not Ammonium or Potassium nitrate .
    The volume of a pizza of thickness 'a' and radius 'z' is given by pi z z a.

  11. #26
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    How is a Potassium ion "even more dangerous" than a sodium ion? what is your measure of danger?

  12. #27
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    Potassium nitrate is a better oxidiser if it gets heated up by a fire . On it's own it's not so bad . It is used in explosives and some rocket fuels so it is very dangerous if it gets going in a fire .
    The volume of a pizza of thickness 'a' and radius 'z' is given by pi z z a.

  13. #28
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    All three are just fertilisers and meat tenderisers.
    Nothing dangerous about them at all - until you deliberately mix them with a fuel which they can oxydise. The mixtures and methods are not trivial and require research or reasonable chemistry knowledge. It is no more complex to make explosives or rocket fuel by many other means without resorting to fertiliser.....
    But these were easier to control (than, say, pool chlorine.....)
    Cheers, Joe
    again completely retired - more time to contemplate projects and spend more shed time....

  14. #29
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    Hey Joe,

    I'll put my hand up for a couple of kilos if it's still available.

    Bob.

  15. #30
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    Anyway it's not Potassium nitrate you need in a bluing formula it's Sodium nitrate . To get the blotchy affect out you may need to degrease the metal before bluing it.
    The volume of a pizza of thickness 'a' and radius 'z' is given by pi z z a.

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