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Powder coating and tempering

Discussion in 'Fit & Finish' started by Jackson, Jan 15, 2015.

  1. Jackson

    Jackson New Member

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    I got a quote of $15 each today for powder coating 3 chef knives that I'm going to try and make. He bakes the blades for 12-15 min. at 400* F. Would it be best to temper the blades before or after the powder coating ? Another unrelated question, Has anyone any knowledge of a 6019 steel ???
     
  2. dancom

    dancom Dust Maker Best Shop Tool

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    Your question is a very good one. If it was my build, I would temper first, then send out for powder coating. Several reasons. The first is, I've always made it my practice to temper after hardening as soon as possible.

    The second reason is that powder coating does burn. Two hours at 400°F in the tempering oven it's likely going to discolour or scorch the coating. I've seen this when powder coating white and baking at my work. The white went yellowy-brown when over cooked. Maybe on black wouldn't be noticeable, but why risk ruining the finish. Two hours in the oven is over 4 times longer than Sherwin-Williams recommends.

    The question is, can you be certain the powder coater is not going to go to hotter, say to 500°F? This could impact the hardness of the steel. As a rule you don't want to go higher than the initial tempering temperature. That said, 400°F range is a pretty common tempering temperature for a lot of different steels. For example, I use 400°F (205°C) for CPM154 when aiming for a hardness of Rockwell 59. According to the datasheet, tempering at 500°F should drop it a point. It may not be a big deal, but something to think about. Recently I've seen posts by people putting knives on red hot stove element so as to make them "look cool." I can't say what that does to the tempering, but I'd avoid that practice. :)

    Sorry I can't help with the 6109 steel.

    Dan
     
  3. Grayzer86

    Grayzer86 Active Member

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    That stove top trend is rediculous. I have also seen people "heat anodizing" knives to "make them look awesome" with torches. They have no idea that by the time they get those "cool" blues, purples, and greys, they have pretty much ruined the knife.
     
  4. Jackson

    Jackson New Member

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    Thanks Dan, I think I was reading last night that a knife should be tempered as soon as possible after hardening in one of MythTakens tutorials. Lots of good advice here. Thanks all
     
  5. Rob W

    Rob W Active Member

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    In general yes when steel reaches room temp or your able to hold in hand but that depends on steel type and many variables, cryo , forging etc
    Jackson I highly recommend doing some research on proven approaches and methods.....
    Couple Masters that come to mind , Kevin Cashen, Ed Fowler, Lin Rhea.......then experiment for yourself
    Although most are trying to be helpful; there are way to many keyboard knife makers on the Internet with limited experience that say this is how you do it.......which just may be info they thought they read or heard , try it test it and you'll be better off in the end for sure , good luck with it , let us know how the powder coating goes !!!
     
  6. Jim T

    Jim T Active Member

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    Gotta agree with you, Rob. Nothing can ruin a good knife faster than following bad advice.
     
  7. dancom

    dancom Dust Maker Best Shop Tool

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    Gee I hope you guys weren't implying that Tim and I are giving bad advice! :p
     
  8. Jim T

    Jim T Active Member

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    Not at all, Dan! As a matter of fact, I'm always following your posts because they often include great "how-to's" and offer inspiration to those of us not nearly as accomplished (driven?) as you. :)

    Jim T
     

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