Heat Treating O-1

fitzo, no i didnt paint the inside or coat it, from what i had read it seemed that u need the small gap were the bricks touch each other, otherwise the fire bricks crack up real bad. i did use the firestop sealeant on all the sheetmetal seams and on the bolts that come from back of unit were it gets power.
 
Dakota 11,

Sounds like a great little set up.

You mentioned "a build floating around the web". Any hints as to where the curious might find this info.?

Have you thought about contacting one of the kiln manufactures about having a production model made, you being their dealer of course!?

For doing single blades or rehetreating screw ups, this little oven would be a perfect compliment to a larger oven. Fast and save on the elect. bill too.

Thanks for the sharing the info.

Rod
 
www.britishblades.com on left side of scren is tutorials and how to's. click that and brings up new screen. from there scroll down and find how to build a ht oven. mine is exactly like this build cept i used a layer of kaowool and his door is nicer then mine
 
fitzo said:
Dakota11, I would be very interested in seeing a foto of the interior of your kiln; very specifically, the placement of the thermocouple relative to the heating coils. Thanks.
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Still if you could manage some photo's it would help the imaginationly challenged among us.
I did download the British tutorial Thanks
 
I use a coal forge, with coke, so it's a very clean fire, and if you don't let it burn shallow, and use a nice thick layer of coke, and dont try to win crancking championship with the blower, or close the electric blower to a steady, gentle breath, you'll have a reducing atmosphere on top of the forge, that means that the blade shouldn't decarb at all.
Actually it will, as there's still oxygen in the air around, but very slowly.
For oil quenchants, I know, I should get some, but can't seem to get a source here in Italy, which deals small enough quantities.
:rolleyes:
 
Leu Custom said:
Stacy: ahhh you're right! I guess a) it all depends on the kind of blade grind you're going to do...if it's flat grind, then no biggy, but if you're doing say a V Grind and don't want to lose the grain on the surface itself by over grinding/polishing, then there would be more of an issue. I suppose in a gas forge, the temperature reaches 1500'F in no time flat whereas a kiln takes a bit of time to get from 1000'F to 1500'F. I guess if you're only austenizing for 5 minutes, then no big deal. Stainless steel foil is really only for air-hardening steels mainly, but whatever less of a mess one has to clean up the better!
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Stacy Apelt said:
Thus, there is no reason for foil with O-1, and many reasons not to use it.
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A V-grind is not significantly different than flat grind or hollow grind in finishing or heat treating, other than it should be easier and a faster since you have one completely flat surface. It is apparent that some folks really don't like to spend any time cleaning up their blades after HT. You can bring the grain back in the steel with enough finishing. As a matter of fact, Scott Slobodian does exactly this with 1050, polishing it until the mill grain shows and simulating hada/nie.

Consider one of the most common questions from people using carbon steel:
"Why did my blade warp?"
Common answer:
"Maybe your grinds are uneven"

What does this tell you? If you add a variable like foil, you're adding an uneven surface... unless, of course, you try to cut it out of the packet, in which case you're exposing the blade to room temp for too long. How do you propose you do something like a differential heat treat with the foil method?

Instead of accepting a reasonable response to your erroneous advice, you argue and finally back peddle. Hiding behind a "style" is no excuse for poor heat-treating or advice, nor is it an excuse for poor fit and finish, in my book. Man-up and admit you were just plain wrong.
 
First, always place what ever Mete says about heat treat at top of list - above all us 'seat of the pants' knife makers (I speak for myself and some but by far not all us here). As for my experience with O1; soak at about 1475 F. but before that bring up to austenitizing temperature rather casually. Soak time depends on thickness of steel. It will not be long for even the thickest of our blades. Bringing temp. up rather slowly will help allow the steel heat more thoroughly throughout its thickness. If using a forge where controlled temperature is not available use your eyes and timing while using your eyes. With a forge or open furnace you can achieve a killer heat treat on simply high carbon steels. The O1 is a poster steel for this, even though it has a bit more than just simple carbon composition. In the lack of external light, in the dark, you can see the O1 go from color to darkness shadowing. Timing achieved with experience (about 15 - 20 seconds of observing the dark shadows - that grow until no longer growing - before retrieving to pre-heated quench) usually produces most good results. I have reluctantly become a real believer in multiple quenching (multiple austenitizing). A couple or three proper soaks and quenches should turn your O1 into a killer blade if controlled tempering is performed. You can quench your O1 in off the shelf vegetable oil. Quenchant pre-heat temperature and time in quench may vary per thickness of steel.

rlinger
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rlinger said:
In the lack of external light, in the dark, you can see the O1 go from color to darkness shadowing. Timing achieved with experience (about 15 - 20 seconds of observing the dark shadows - that grow until no longer growing - before retrieving to pre-heated quench) usually produces most good results.
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Sorry, my english is usually good but you ave lost me here.
What do you mean "going from color to darkness shadowing"?
And what do you mean with "the dark shadows growing"? (sounds like an ominous prophecy but I'm sure you mean something about the surface of the steel that I don't quite get:p)


I have reluctantly become a real believer in multiple quenching (multiple austenitizing). A couple or three proper soaks and quenches should turn your O1 into a killer blade if controlled tempering is performed. You can quench your O1 in off the shelf vegetable oil. Quenchant pre-heat temperature and time in quench may vary per thickness of steel.
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I usually do a little pre-heat with my 5W30 oil, and bring it around 30-40 °C, as it speeds quench (by reducing a little the viscosity of the oil.
How hot do you get it?
 
Alarion said:
Sorry, my english is usually good but you ave lost me here.
What do you mean "going from color to darkness shadowing"?
And what do you mean with "the dark shadows growing"? (sounds like an ominous prophecy but I'm sure you mean something about the surface of the steel that I don't quite get:p)
QUOTE]


Alarion,

This is not a subject I know a lot about because I use a digital furnace, but since there hasn't been a reply all day I'll try to answer it.

Some people use the "non magnetic" point to know when they're hot enough. The curie point? As you know this doesn't work for more complex steels.

There is a temperature for steels where the intensity of the glow drops off sharply. It probably has to do with a phase transition. The color is the same, but it is darker, looks like a shadow. Because your blade is in a fire, it is not all the same temperature, so this will happen in some areas sooner than others.

They say that as you're passing this point it looks like a shimmering, with waves moving back and forth along the blade. Very distinct, can't miss it.

You'd have to be in a dark setting to see this, and you'll need to be paying attention when you reach that critical temperature.

I wish I could tell you more, but I've only read about it. Sorry.

Go out to your forge and heat a piece of carbon steel and let us know what you find.

Thanks,
Nathan
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Oh, that! Ok.
I know of the phenomenon, but never actually paid attention to it.
Will try it next time I'm at the forge (which unfortunately will be at least a month from now...:rolleyes:)
 
Oil is usually heated to about 55 C [130 F]..."darkness shadowing" must be a West Virginia term !!
 
firebricks i got locally i belive i got 26 for for 98 dollars, think darren ellis sells 20 for 85 plus shipping. i believe u will need 23 or so. budget casting supplys is were i got the elements. 50 dollars for 2. on ebay is a company auberiers or something like that . anyways i got pid controller, ssr, and thermocouple 89 dollars. the high temp wire i got locally from appliance repair shop a few feet of it and the plug in for 220 was 20 dollars. that puts u right at 250 ish. u will need the sheetmetal and angle iron also. i had both on hand so didnt cost me anything . not sure what those components would cost were u are. without having everything on hand still probably 300 or so.
 
Dakota 11 said:
firebricks i got locally i belive i got 26 for for 98 dollars, think darren ellis sells 20 for 85 plus shipping. i believe u will need 23 or so. budget casting supplys is were i got the elements. 50 dollars for 2. on ebay is a company auberiers or something like that . anyways i got pid controller, ssr, and thermocouple 89 dollars. the high temp wire i got locally from appliance repair shop a few feet of it and the plug in for 220 was 20 dollars. that puts u right at 250 ish. u will need the sheetmetal and angle iron also. i had both on hand so didnt cost me anything . not sure what those components would cost were u are. without having everything on hand still probably 300 or so.
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Thanks!!!!
 
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