Heat treat question

I have on order the even heat kiln and I was wondering when it comes to heat treating 1095 is it possible to heat treat 5 knives at a time? Also once the kiln reaches 1500 degrees and you put the blades in do you let it then soak for 10 minutes and then start quenching each blade? Also how should I do this so that my blades do t cool down to much from trying to quench multiple blades. I appreciate the help in advance. I just started making knives about 2 months ago and just wanting some insight.
 

Brad Walker

KNIFE MAKER
New Jersey Steel Baron has heat treat info on just about every type of steel. I would recommend researching their info on 1095. The only issue with treating multiple blades is it will overheat your quench oil if you only have 1 tank.
 

tkroenlein

Well-Known Member
You should start with 1 blade and work up from there. I can all but guarantee some catastrophic failure of process at 5. 3-4 knives, depending on size, will heat my 3 gallons of oil and the big steel pipe it's in as hot as I'll use it. If you get your oil hot enough, it will burn. 2 gallons will not do 5 blades consecutively in any way you arrange it.
 
So
You should start with 1 blade and work up from there. I can all but guarantee some catastrophic failure of process at 5. 3-4 knives, depending on size, will heat my 3 gallons of oil and the big steel pipe it's in as hot as I'll use it. If you get your oil hot enough, it will burn. 2 gallons will not do 5 blades consecutively in any way you arrange it.
I could do probably 2 blades safely? And is flare up ok for parks 50 or should it nor flare up? How long would you say to let the blade soak at 1500?
 

tkroenlein

Well-Known Member
No oil should flare up. That happens when you have more heat than your volume of quenchant can dissipate quickly enough to keep from flashing off, or the work isn't completely submerged in the oil so you have hot metal, vaporized oil, and oxygen all mixed together. For 2 gallons in a vertical steel quench tank, you probably should be able to do 2.

I can't speak to 1095 recipes, as I don't use it. I probably wouldn't start at 1500 though. Maybe 1475F. 10 minutes is probably ok.
 
So how would you do say three knives so that the first doesn’t cool down to quick before the third one is ready for temper? I guess just have a timer set for each knive in the oven so they come out at different times for tempering.
 

Chris Railey

Well-Known Member
Maybe 1475F. 10 minutes is probably ok.
This is what I do for 1095 and I like it. I would start there. On the quench flaring up, like Todd said above, it should not, period. Plunge your knife into the oil carefully and leave it there moving it up and down in the oil never breaking the surface. The Forged In Fire quench where you put it in oil for like five seconds and pull it out so it bursts into flames is about the stupidest way to quench steel. It is done for T.V. drama only. No person who is serious about heat treating their own steel does it the FIF way.

Five knives at a time is going to be hard to pull off without your steel temp dropping to levels where your as quenched hardness may be changed.. It is not impossible, but I think you would likely start a fire in your shop. Not to mention, you would likely overheat your oil to a point where it would not quench properly unless you have a very large tank. The following is my HT for 1095 in my kiln, if you start here you can develop your own process to your liking. I normally HT two knives of the same steel at a time. To begin, I place a piece of scrap steel (normally a RR spike) in the kiln and ramp to 1450F as fast as possible. I remove the spike and use it to pre-heat my oil. I place my knives in the kiln and ramp to 1475F as quick as possible. The steel needs to "soak" at 1475 for the five to ten minutes so I do not start that time until my kiln reaches 1475 with the blades in it. When you introduce the blades they will pull heat from the kiln until they equalize with it's temperature so you have to wait until it comes back to 1475F. Once the temp reaches 1475F I start a timer for five to ten minutes no more than ten minutes, period. When the timer goes off I quench the first blade, then the second. After this your kiln temp will have dropped so if you want to HT another blade or two you can now place them in the kiln and ramp back to 1475F and repeat. Just remember if you do this, you may need two quench tanks so you do not overheat your oil. I have a steel five gallon bucket and have never quenched more than three in a row. Good luck and make sure you have a fire extinguisher or two handy for emergencies. I am not a safety harper, but that is just common sense.
 
Tha k you
This is what I do for 1095 and I like it. I would start there. On the quench flaring up, like Todd said above, it should not, period. Plunge your knife into the oil carefully and leave it there moving it up and down in the oil never breaking the surface. The Forged In Fire quench where you put it in oil for like five seconds and pull it out so it bursts into flames is about the stupidest way to quench steel. It is done for T.V. drama only. No person who is serious about heat treating their own steel does it the FIF way.

Five knives at a time is going to be hard to pull off without your steel temp dropping to levels where your as quenched hardness may be changed.. It is not impossible, but I think you would likely start a fire in your shop. Not to mention, you would likely overheat your oil to a point where it would not quench properly unless you have a very large tank. The following is my HT for 1095 in my kiln, if you start here you can develop your own process to your liking. I normally HT two knives of the same steel at a time. To begin, I place a piece of scrap steel (normally a RR spike) in the kiln and ramp to 1450F as fast as possible. I remove the spike and use it to pre-heat my oil. I place my knives in the kiln and ramp to 1475F as quick as possible. The steel needs to "soak" at 1475 for the five to ten minutes so I do not start that time until my kiln reaches 1475 with the blades in it. When you introduce the blades they will pull heat from the kiln until they equalize with it's temperature so you have to wait until it comes back to 1475F. Once the temp reaches 1475F I start a timer for five to ten minutes no more than ten minutes, period. When the timer goes off I quench the first blade, then the second. After this your kiln temp will have dropped so if you want to HT another blade or two you can now place them in the kiln and ramp back to 1475F and repeat. Just remember if you do this, you may need two quench tanks so you do not overheat your oil. I have a steel five gallon bucket and have never quenched more than three in a row. Good luck and make sure you have a fire extinguisher or two handy for emergencies. I am not a safety harper, but that is just common sense.
Thank you so much for your input. I will definitely try this. For now until I get my kiln I’m using my forge. I can’t wait to get my kiln.
 

KenH

Well-Known Member
pre-heat my oil
Chris - are you using Parks 50? I was under the impression that Parks 50 didn't require heating, but best to use at room temp, with a max of 120F. From the Parks sheet.

"The recommended operating temperature range is ambient to 120 o F.
50 QUENCH OIL is as effective at 50F as it is at 120F because of its low viscosity."
 
Chris - are you using Parks 50? I was under the impression that Parks 50 didn't require heating, but best to use at room temp, with a max of 120F. From the Parks sheet.

"The recommended operating temperature range is ambient to 120 o F.
50 QUENCH OIL is as effective at 50F as it is at 120F because of its low viscosity."
Yea that’s what I though also. I know with canola oil you have to pre heat but you do t for parks 50.
 

Chris Railey

Well-Known Member
Thanks, like you I used to HT in a forge so in my eyes it was not necessary to pay for the expensive quench oils until you have better temperature control. Now that I have temp control and some idea of how to use it, I believe it is time to upgrade my oil use.
 
Thanks, like you I used to HT in a forge so in my eyes it was not necessary to pay for the expensive quench oils until you have better temperature control. Now that I have temp control and some idea of how to use it, I believe it is time to upgrade my oil use.
How did you do your heat treating your Forge?
 

Chris Railey

Well-Known Member
First by color, then I learned a little more and did it by the steel's Curie point (non-magnetic). Then I learned a little more and was able to spot decalescence which, in my opinion, was the best way without having a thermocouple or two in your forge.
 
First by color, then I learned a little more and did it by the steel's Curie point (non-magnetic). Then I learned a little more and was able to spot decalescence which, in my opinion, was the best way without having a thermocouple or two in your forge.
Can you tell me how you see decalescense?
 

Chris Railey

Well-Known Member
There are better on the forum (like Kevin Cashen) to answer but in my words there is a funky little shadowy wave that appears as the point of decalescence is reached. Keeping your lights low in the shop while looking helped me. It's kind of like when you are hunting, and you hear a squirrel and you think maybe its a deer, but when you hear a deer, you know its a deer. You will know when you see it. Sorry, that is the best I have. Told you there are better to answer.
 
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