Forge is a going. Take a look

[NJStricker]

You want enough oil so that it is deep enough to quench the blade, and a little past.

The volume really depends on what container you have, but a large coffee can would be fine if only heat treating a couple of blades at a time. Keep a lid handy to cover in case the flames get too bad. Some people use old military ammo cans. There's a lid to smother the flames, and it's convenient storage.

You'll want to preheat the oil to about 135-150 F before the quench.

If you were to heat treat a large batch of knives, then you would want a larger volume of oil so that the oil temp doesn't increase too much by the time you quench the last blades.

[squigly1965]

Do I plunge it into the oil or slowly submerge it. And does it need to be vertical or horizontal?

[squigly1965]

would mineral oil that i can get at the drug store be alright for quenching? I think it also has vitamin E in it

[samuraibill]

I am not really into forging but I have read that some people use vegetable oil. I could be completely off though.

I was looking at the pics you posted of the blank with all the pits in it, and it reminded how much I like seeing knives finished with some of the pits left in the blade. The rough beat to hell look is a nice touch. Its kind of like seeing a knife made from a file or rasp. Keep hammerin' on. good luck.

[NJStricker]

Originally Posted by squigly1965

would mineral oil that i can get at the drug store be alright for quenching? I think it also has vitamin E in it

Do you know anyone with a turkey fryer? Ask them for their old peanut oil.

[Ray Rogers]

You can't have too much oil and 3 gallons is generally plenty. The idea is to have enough oil that the blade can't heat it up very much. The oil should be at 125 F before you quench the blade for best results. Heat the oil with some scrap steel.

Considering the size of your forge, I'd say do the blades one at a time.

The edge should be about as thick as a dime to avoid getting a wavy edge.

Sounds like you're doing fine on the hammering ....

[squigly1965]

I dont know any one that has any old fryer oil right now. I might know where there is some old motor oil. Would that work. I want to do this right but I'm trying to get by as cheaply as I can. If I should wait I will. I got a couple side jobs coming up probably next month. That will give me a bit more spending money.

I take it you mean just heat the scrap up and quench it? Once I do get the Oil to temp. Do I slowly submerge the metal. Or just put it in. When will I know it can be taking out?

[Ray Rogers]

At this point in your endeavor any oil will do: motor oil, hydraulic fluid, ATF, mineral oil, etc.

Yes, heat scrap and quench it.

Definitely put the hot blade in the oil as quickly as humanly possible. Some guys do it horizontally, other do it vertically. Either will work. Horizontally makes it easier to do an edge quench if you decide to try that later but vertically has a slightly better chance of avoiding warpage. Some of that choice will depend on the size and shape of your quench tank which, BTW, should be some kind of metal, definitely not plastic.

Leave the blade in the oil until it has cooled to under 125 F. That means it will be warm to the touch of your bare hand but no where near hot enough to burn your fingers. This generally means the blade stays in the oil at least 30 minutes but could easily be longer. Then, wipe off the excess oil and temper the blade ASAP ....

[NJStricker]

Get yourself an old or cheap candy thermometer, and use it to monitor your oil temp.

Get your forge warmed up. Take some scrap metal--mild steel, short section of angle iron, and old RR spike, whatever--and heat it up in the forge. Once it's hot, set it in your oil until the oil is around 125.

Then, heat your blade in the forge. Pull it out occasionally and check the edge with a magnet (a metal one, not the cheap plastic ones). Once your blade no longer sticks to the magnet, put it back in the forge for a few seconds.

Now for the quench. For now, keep it simple--no interrupted quench, no differential quench, no clay back coating. You're going to dunk the entire blade in plus the first inch or so of the front of the handle. Make sure you've drilled your pin/bolt holes first!

When you dunk the blade, you can put it in point first with the point facing downward, or edge first with the spine facing upward.

Either way, the blade should enter the oil vertically so that both sides of the blade are being submerged simultaneously. If the left or right side enters the oil first, then one side of the blade will cool more quickly than the other. As the steel cools, it contracts. If one side cools faster than the other, it will contract faster than the other, causing the blade to warp. That's one reason you want to dunk the blade quickly, but smoothly.

Once the red hot blade hits the oil, a couple of things will happen. First, the hot blade will heat the oil so that it starts to boil. The oil immediately next to the blade will turn into a gas, which will then rise to the surface of the oil and possibly catch fire. The flames shouldn't last long, but you should keep a lid handy to put over your quenching container if they persist. Once consequence of the oil vaporizing is that it will form a "vapor jacket" on either side of the blade, which doesn't cool the steel nearly as fast as the liquified oil will.

So, as soon as you dunk your blade (assuming you've dunked it edge first), you will want to move the blade forward and back to keep the blade in contact with liquid oil and reducing the amount of time the steel is contact with the vapor jacket. Avoid moving the blade side to side, as this could contribute to warping.

You'll want to keep the blade in the oil until it cools enough to handle with your bare hands.

Once it has cooled, you'll want to check to see if your hardening cycle has been successful(quenching is just one part of the heat treating process). A simple/cheap way to do this is to run a file across the edge. If your steel has hardened then your file will skate across without biting into the blade. It will have a "glassy" sound, as opposed to the duller sound of a file running across mild or annealed steel. If your blade has hardened, then it is also very brittle at this point. Dropping it on a hard surface could cause it to shatter.

Next, you will need to temper. Tempering should be done as soon as possible after hardening (in other words, while the blade is still warm, don't wait until the next day if you can help it). I forget what steel you are working with, but different steels should be tempered at different temperatures. You'll need to experiment to see what gives you a good working edge. Try tempering for an hour at 375F to start. If your blade is still very hard then you may need to temper for another hour at 400, and so on.

A simple way to check the hardness is to do a "brass rod test." Grind a cutting edge onto your blade. Then, run the edge perpendicularly across a 1/4 inch brass rod. If the edge is still too hard (needs to be tempered further) then the edge will chip. If the edge is too soft (tempered at too high a temperature, softening the steel too much, in which case you need to re-harden) then the edge will roll/curl and stay deformed. If you get the tempering right for your steel then the edge will flex slightly as you draw it over the rod with a little pressure, and then spring back to position.

You'll have some burned oil and gunk on your blade after you finish your quenching and tempering cycles. Just wipe off what you can with an old towel, then soak the blade in vinegar over night. The vinegar will help dissolve the scale, and will leave the blade a gray color.

You are then ready to hand sand the blade to final finish and install the handle.

[squigly1965]

alrighty I was hoping that was the case. Maybe in the next day or so I should be able to do this. I still need to pick up a toaster oven for the HT.
Anyways I'll post what happened then. Thanks again for the help


Chris

[squigly1965]

Originally Posted by Armory414

Get yourself an old or cheap candy thermometer, and use it to monitor your oil temp.

Get your forge warmed up. Take some scrap metal--mild steel, short section of angle iron, and old RR spike, whatever--and heat it up in the forge. Once it's hot, set it in your oil until the oil is around 125.

Then, heat your blade in the forge. Pull it out occasionally and check the edge with a magnet (a metal one, not the cheap plastic ones). Once your blade no longer sticks to the magnet, put it back in the forge for a few seconds.

Now for the quench. For now, keep it simple--no interrupted quench, no differential quench, no clay back coating. You're going to dunk the entire blade in plus the first inch or so of the front of the handle. Make sure you've drilled your pin/bolt holes first!

When you dunk the blade, you can put it in point first with the point facing downward, or edge first with the spine facing upward.

Either way, the blade should enter the oil vertically so that both sides of the blade are being submerged simultaneously. If the left or right side enters the oil first, then one side of the blade will cool more quickly than the other. As the steel cools, it contracts. If one side cools faster than the other, it will contract faster than the other, causing the blade to warp. That's one reason you want to dunk the blade quickly, but smoothly.

Once the red hot blade hits the oil, a couple of things will happen. First, the hot blade will heat the oil so that it starts to boil. The oil immediately next to the blade will turn into a gas, which will then rise to the surface of the oil and possibly catch fire. The flames shouldn't last long, but you should keep a lid handy to put over your quenching container if they persist. Once consequence of the oil vaporizing is that it will form a "vapor jacket" on either side of the blade, which doesn't cool the steel nearly as fast as the liquified oil will.

So, as soon as you dunk your blade (assuming you've dunked it edge first), you will want to move the blade forward and back to keep the blade in contact with liquid oil and reducing the amount of time the steel is contact with the vapor jacket. Avoid moving the blade side to side, as this could contribute to warping.

You'll want to keep the blade in the oil until it cools enough to handle with your bare hands.

Once it has cooled, you'll want to check to see if your hardening cycle has been successful(quenching is just one part of the heat treating process). A simple/cheap way to do this is to run a file across the edge. If your steel has hardened then your file will skate across without biting into the blade. It will have a "glassy" sound, as opposed to the duller sound of a file running across mild or annealed steel. If your blade has hardened, then it is also very brittle at this point. Dropping it on a hard surface could cause it to shatter.

Next, you will need to temper. Tempering should be done as soon as possible after hardening (in other words, while the blade is still warm, don't wait until the next day if you can help it). I forget what steel you are working with, but different steels should be tempered at different temperatures. You'll need to experiment to see what gives you a good working edge. Try tempering for an hour at 375F to start. If your blade is still very hard then you may need to temper for another hour at 400, and so on.

A simple way to check the hardness is to do a "brass rod test." Grind a cutting edge onto your blade. Then, run the edge perpendicularly across a 1/4 inch brass rod. If the edge is still too hard (needs to be tempered further) then the edge will chip. If the edge is too soft (tempered at too high a temperature, softening the steel too much, in which case you need to re-harden) then the edge will roll/curl and stay deformed. If you get the tempering right for your steel then the edge will flex slightly as you draw it over the rod with a little pressure, and then spring back to position.

You'll have some burned oil and gunk on your blade after you finish your quenching and tempering cycles. Just wipe off what you can with an old towel, then soak the blade in vinegar over night. The vinegar will help dissolve the scale, and will leave the blade a gray color.

You are then ready to hand sand the blade to final finish and install the handle.

I almost forgot about the lanyard hole and pin holes oops. I'm glad you guys are here

[reefera4m]

Originally Posted by Armory414

Get yourself an old or cheap candy thermometer, and use it to monitor your oil temp.

Get your forge warmed up. Take some scrap metal--mild steel, short section of angle iron, and old RR spike, whatever--and heat it up in the forge. Once it's hot, set it in your oil until the oil is around 125.

Then, heat your blade in the forge. Pull it out occasionally and check the edge with a magnet (a metal one, not the cheap plastic ones). Once your blade no longer sticks to the magnet, put it back in the forge for a few seconds.

Now for the quench. For now, keep it simple--no interrupted quench, no differential quench, no clay back coating. You're going to dunk the entire blade in plus the first inch or so of the front of the handle. Make sure you've drilled your pin/bolt holes first!

When you dunk the blade, you can put it in point first with the point facing downward, or edge first with the spine facing upward.

Either way, the blade should enter the oil vertically so that both sides of the blade are being submerged simultaneously. If the left or right side enters the oil first, then one side of the blade will cool more quickly than the other. As the steel cools, it contracts. If one side cools faster than the other, it will contract faster than the other, causing the blade to warp. That's one reason you want to dunk the blade quickly, but smoothly.

Once the red hot blade hits the oil, a couple of things will happen. First, the hot blade will heat the oil so that it starts to boil. The oil immediately next to the blade will turn into a gas, which will then rise to the surface of the oil and possibly catch fire. The flames shouldn't last long, but you should keep a lid handy to put over your quenching container if they persist. Once consequence of the oil vaporizing is that it will form a "vapor jacket" on either side of the blade, which doesn't cool the steel nearly as fast as the liquified oil will.

So, as soon as you dunk your blade (assuming you've dunked it edge first), you will want to move the blade forward and back to keep the blade in contact with liquid oil and reducing the amount of time the steel is contact with the vapor jacket. Avoid moving the blade side to side, as this could contribute to warping.

You'll want to keep the blade in the oil until it cools enough to handle with your bare hands.

Once it has cooled, you'll want to check to see if your hardening cycle has been successful(quenching is just one part of the heat treating process). A simple/cheap way to do this is to run a file across the edge. If your steel has hardened then your file will skate across without biting into the blade. It will have a "glassy" sound, as opposed to the duller sound of a file running across mild or annealed steel. If your blade has hardened, then it is also very brittle at this point. Dropping it on a hard surface could cause it to shatter.

Next, you will need to temper. Tempering should be done as soon as possible after hardening (in other words, while the blade is still warm, don't wait until the next day if you can help it). I forget what steel you are working with, but different steels should be tempered at different temperatures. You'll need to experiment to see what gives you a good working edge. Try tempering for an hour at 375F to start. If your blade is still very hard then you may need to temper for another hour at 400, and so on.

A simple way to check the hardness is to do a "brass rod test." Grind a cutting edge onto your blade. Then, run the edge perpendicularly across a 1/4 inch brass rod. If the edge is still too hard (needs to be tempered further) then the edge will chip. If the edge is too soft (tempered at too high a temperature, softening the steel too much, in which case you need to re-harden) then the edge will roll/curl and stay deformed. If you get the tempering right for your steel then the edge will flex slightly as you draw it over the rod with a little pressure, and then spring back to position.

You'll have some burned oil and gunk on your blade after you finish your quenching and tempering cycles. Just wipe off what you can with an old towel, then soak the blade in vinegar over night. The vinegar will help dissolve the scale, and will leave the blade a gray color.

You are then ready to hand sand the blade to final finish and install the handle.

I agree with almost everything you wrote - with two exceptions. I think you'll have a very difficult time hardening mild steel, much less a RR spike', to the point where you can get a good file to 'skate' across the edge. And trying to accomplish this could be extremely frustrating. I've tried this with a number of RR spikes (the 'HC' grade) as well as some mild steel flat stock and never could get them that hard. 5160 - no problem.

The other point is grinding the edge. Unless done with great care, you run the real risk of overheating the edge and reversing what you accomplished with the hardening cycle. You'd be better off with a coarse, then fine, diamond hone, or progressively finer wet/dry sandpaper with a good backing plate. If you do use a grinder, hold the steel with bare hands to feel the heat as it builds up and cool often with plain water. Don't let it get to hot to handle.

[NJStricker]

The mild steel and RR spike are used only to pre-heat the oil, I'm not recommending them for blades.

Grinding heat treated blades, either to establish the cutting edge or to remove decarb is fairly common. I suspect with the tools that squigly has he'll need to use files. The woodworking hand-held belt sander he used to plain down his forge marks will run too fast, I think, and heat the blade too quickly for this task.

[squigly1965]

The RR spike thing I believe was just used to heat the oil up to quenching temp



as for the edge grinding I have a 200 grit Diamond sharpener would that be sufficient? But I think He meant with a belt grinder. I only have a 3x18 I think that would heat up fast so the diamond thing may be a good idea. IDK though. I could grind in spurts though maybe grind one blade then the other back and forth

[squigly1965]

LOL you got to it before I did

Would the Diamond Sharpener do the job?