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Turbo Instead Of Foil

Discussion in 'Heat Treating' started by dominion22, Dec 28, 2015.

  1. dominion22

    dominion22 New Member

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    just discovered a product called Turco on another site. Anyone heard of it or used it instead of wrapping blade in foil? Am having trouble getting blade out of foil in time to quench.
     
  2. dancom

    dancom Dust Maker Best Shop Tool

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    Hi, are you working with stainless steel?
    I use something called Condursal Z1100 (1100°C rated). I've heard of Turco, but I think it's has a low temperature rating.

    Dan
     
  3. dominion22

    dominion22 New Member

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    I have been using 440C and I plate quench in the foil so I don't worry about that, but I made a couple of knives out of 1095 and one I didn't wrap and had lots of polishing after. Tried to wrap the second but couldn't get it out of the foil fast enough for proper quench.
     
  4. John Noon

    John Noon Well-Known Member

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    Is it that critical to take the blade out of the foil in order to quench? Thought I read some where that you could oil quench in the foil. There is so little mass to the foil I though it would make no difference during an air quench if plates were used.
     
  5. dominion22

    dominion22 New Member

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    I don't know if you can quench in foil or not, I don't have enough experience , but everything I've read about using carbon steels is they are quenched out of the foil. I plate quenched 440C in the foil and it came out hard.
     
  6. dancom

    dancom Dust Maker Best Shop Tool

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    I do mostly stainless, but once in a while I do some 1084 or O1. I didn't think you'd need to foil wrap a 10xx steel unless you are soaking it for an extended period and decarburization was a concern. With these steels we're dealing with around 850°C for 1 to 15 minutes then quenching. I guess some carbon will leave, but what amount I cannot say.

    Decarburization is more pronounced in stainless steel alloys. These require higher soak temperatures in excess of 1000°C and that's where the foil, protective coating and inert gas flooding comes in.

    The way I have been doing it: protect the stainless and leave the regular high carbon steel as-is. To speed your cleanup of 10xx steel, coat the blade with a very thin coating of high temperature mortar. Water down and smooth it on.

    I have never oil quenched stainless in the foil, only with Condursal. Empirically, I can say that oil quenching results in higher hardness than copper plate quenching on CPM154 and AEB-L.

    Plate quenching is kinda weird if you think about it. Assume you have your rough bevels all set and the steel is in the bag. When you plate quench, you actually cool the flats of the blade much faster the edge. The edge remains in the air while the flats are in contact with your plates which are sucking the heat out. In September, I asked Ed Storch about this and learned he too was using a protective coating and oil quenching to get around this problem. In his words "expect to lose a few points when using foil."

    One way to get better response in the foil is to grind the bevels after heat treatment. This way all of the stock is flat and the whole thing contacts the plates when quenching. It my preferred way for another reason: it reduces the risk of warping in thinner stock. But comes at the cost of grinding belts and the slight risk of killing the temper if you get too hot on the grinder. Keep a bucket of water...err ice handy ;-)


    Hope some of this helps.

    Dan
     
    Last edited: Dec 30, 2015
    krash-bang likes this.
  7. dominion22

    dominion22 New Member

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    Thanks, it does help. I plate quenched a couple of stainless blades in foil and the edges were good and hard so I will probably try this method again. I'll look into getting something to coat the carbon blades.
     
  8. dancom

    dancom Dust Maker Best Shop Tool

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    I did plate quench in foil too and there was no problem with the hardness. If you wanted to make a high hardness knife e.g. Gyuto @ HRC62+, then you may want to oil quench the stainless to get those extra few points that Ed was talking about. Stacy Apelt recommended the watered down mortar. A light even coat, similar to the base coat for making hamon.

    Let us know how it goes!

    Dan
     
  9. dominion22

    dominion22 New Member

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    Where can I get the mortar that was suggested?
     
  10. John Noon

    John Noon Well-Known Member

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    The types of clay and mortar are mentioned here somewhere, of course I could not the post when at the store and ended up with a small jar of fire brick clay/cement.

    I think I searched Hamon last time I found it, possibly clay?
     
  11. dancom

    dancom Dust Maker Best Shop Tool

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    I use Imperial Hi-Temp Fireplace Mortar from Canadian Tire. I think Fred uses the same.

    Dan
     
  12. doublehelix1

    doublehelix1 New Member

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    Hey Dan, Where did you get your Condursal?
     
  13. dancom

    dancom Dust Maker Best Shop Tool

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  14. doublehelix1

    doublehelix1 New Member

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    Holy cow $170+gst+hazmat fee, and the quoted price was from 2015 so will likely increase 30%. Worth it?
     
  15. dancom

    dancom Dust Maker Best Shop Tool

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    Wow, I guess that's our tanking dollar. I think I paid $140 or so and it was delivered by the sales rep when he was in town, so no shipping or Dangerous Goods shipping.
    I think it's worth it. A can will do a ton of knives. I am thinking at least 100 good sized knives. And not buying any more foil which was $60 to $70 for a 10 foot roll before shipping. Also, I am oil quenching stainless and the foil is a giant pain in that regard.

    Dan
     

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