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Heat Treating Problems.

Discussion in 'Heat Treating' started by SDMay, Aug 20, 2016.

  1. SDMay

    SDMay Active Member

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    I'm finally at heat treat and I can't get it to work.

    Map gas torch, outside, windy. I can get one small 1/2 section non magnetic and try to keep going up the blade but I can't keep things hot. I get the one section done, keep going and even if I come back the start is back to magnetic. I wanted to do the full blade but realize that it probably isn't going to work.

    I spent an hour outside trying and just couldn't get it. Tried the spine to edge, edge only, half way up... I hope that I haven't ruined the blade as I had scale forming. I have pics that I will try to post but firm some reason they won't email.


    Any thought/help would be appreciated.
     
  2. Prevenge

    Prevenge Member

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    Are you using a two brick forge?
     
  3. SDMay

    SDMay Active Member

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    No I am trying to do it with just the torch. I have seen/heard of it done this way.
     
  4. Prevenge

    Prevenge Member

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    I would never attempt it personally ...especially in the wind. Maybe with oxy/acet and a rosebud head but I can't see one of those little torches being able to do it fast enough. And with that much air in the mix you will get more scale than you would using a forge of any sort. I have never actually tried it so I am not saying it can not be done but...... I can't see it being very fun. You need a couple good soft firebricks...hell even a one brick forge would probably do. Basically anything would be better than trying to get to critical in open atmosphere....maybe even fireplace bricks. I have heard of tempering this way but not hardening. Good luck!
     
  5. SDMay

    SDMay Active Member

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    Looks like I will be waiting for payday to build a forge. Thank for the info.
     
  6. dancom

    dancom Dust Maker Best Shop Tool

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  7. SDMay

    SDMay Active Member

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    I was online last night and I think that I will make a can forge. I will use a gallon paint can. Found one where a guy used plater of Paris and sand for the refractory material. Thanks for the answers guys.
     
  8. Prevenge

    Prevenge Member

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    I guess there is also the simplest solution too .... @bobbybirds uses a "plain old fire" ? When I first started forging stuff I used a fire fed with wood and fir bark supplemented with charcoal I made. I used an air compressor as a blower haha. It was time consuming but it got more than hot enough.
     
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  9. bobbybirds

    bobbybirds Best New Maker

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    Even simpler... I use a weed torch cranked up on propane in one hand, and the knife held in vise grips in the other... It get 1/8th inch and smaller cherry red non-magnetic pretty darn quickly. Thicker than that takes a bit more time but still gets everything hot enough. I am just about ready to build a paint can forge though. It will be more consistent and use less propane.
     
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  10. Mythtaken

    Mythtaken Staff Member CKM Staff

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    You can do it using a torch but you need a way to keep the heat in. The simple way is to buy a few firebricks (the hard ones) and stack them to make a small oven-like enclosure (with floor), just big enough to fit the blade while moving it around with the vice grips. Then torch away. That's what I did starting out.

    Oh, and don't try to do it outside on a windy day. It's better under cover (like the garage with the door open for ventilation).
     
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  11. SDMay

    SDMay Active Member

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    Got my blade heat treated! Made a fire brick forge after another fail out of the wind last night. I think that I will have to stack them differently to make the chamber smaller. I hope I'm totally successful as I lost my magnet last night and couldn't find another today. I took it to a colour I knew was non magnetic with my last attempts and it was for sure hotter going into the oil. File slid across the curtting edge when I was done so I'm thinking it will be fine.

    It is in the oven as we speak tempering. Did some handle work while I am waiting. Twenty minutes left on the first cycle.
     
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  12. SDMay

    SDMay Active Member

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    Well I got it tempered. Thank goodness my wife was here as I set my oven timer wrong and almost shorted the first cycle by 40 minutes. Definetaly sounds different when you hit it against something. Even makes the ring when tapped with another piece of metal just like in shop class.

    One thing I did notice is that it didn't really change colour during the temper, just got a bit darker. Could this be from to much scale built up on it?
     
  13. Prevenge

    Prevenge Member

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    Chill...it will probably be from the oil. What steel?
     
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  14. Prevenge

    Prevenge Member

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    Think of the black finish on a cast iron pan. That is almost exactly how that is done...by baking something oily onto it. The oil mates with the oxides and solidifies. Aka rust bluing...organic and gluten free
     
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  15. John Noon

    John Noon Well-Known Member

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    Exactly the finish I put on a wannabe bowie knife. after quench sand off mill scale with 400 grit apply cold blue three times, buff with steel wool between coats.

    Then stick in oven for temper, apply another coat od bluing after temper cycle and repeat. Not sure how durable the finish is just yet but it is a nice black coating
     
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  16. SDMay

    SDMay Active Member

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    It's 1084. Took it out this morning and sure enough everything cleaned up with sand paper. Got it all sanded to 400 and now it is sitting all clamped up waiting for the epoxy to dry.
     
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