Size of Quench Tube?

[Michael Pikula]

I have a viking blade that I put a bunch of hand work time into and I am getting ready to heat treat it. I have a high temp salt bath and a low temp bath that I normally quench my L6 into. Since this blade is from Don's W2 I was planning on quenching into water instead of low temp salts since I don't think that the blade will harden enough, am I right on this? I don't have the best access to lots of pipe so I was wondering what size pipe I should be looking for to hold the water?

 

Thanks!

[jake cleland]

don't quench in water - unless you're shooting for a fancy hamon and positive sori, there is no reason for it, and you're just asking for trouble, particularly with double edged pieces.

 

i'm not sure about the low-temp salts, they should be pretty quick getting past the pearlite nose, but whether they're fast enough, i don't know - i don't know enough about them. Hopefully someone will chime in who does. You could maybe make a small test blade and see if it hardens in the salts? my guess is it will, but it's just a guess...

 

if not, i'd go with an oil quench - with high carbon shallow hardening steels like 1095, 1086M, W2, W1 etc, i think the most important thing is a long soak time, which should be no problem with your set up.

 

my heat treating setup is very low tech, so i generally try to soak just over non mag for a minute or two, and then bump up the temp around 50f - 75f just before the quench, which is the only way i can get a hamon in oil on these steels. without clay, after three normalisations, if i bring it to just above non mag, and quench straight away in warm oil, it'll harden about 1/3rd of the blade; if you're not using clay, then depending on your normalizing you'll probably still get a differential hardness in oil, and if you polish and etch for it you'll see some kind of transition line, but for viking pieces this seems to have been common.

 

as for the size of the quench tube, 4 -6" diameter should do you fine, and a few inches longer than your blade - i use two or three malt whisky tubes taped together sitting in a jug and filled with old veggie oil, when i have to jerry-rig something for longer blades, and it holds up fine for my purposes, although it's obviously not ideal - the greater the diameter the more efficient the heat transfer, and peanut or canola oil should be faster than veg.

Edited June 22, 2009 by jake cleland

[kb0fhp]

don't quench in water - unless you're shooting for a fancy hamon and positive sori, there is no reason for it, and you're just asking for trouble, particularly with double edged pieces.

 

i'm not sure about the low-temp salts, they should be pretty quick getting past the pearlite nose, but whether they're fast enough, i don't know - i don't know enough about them. Hopefully someone will chime in who does. You could maybe make a small test blade and see if it hardens in the salts? my guess is it will, but it's just a guess...

 

if not, i'd go with an oil quench - with high carbon shallow hardening steels like 1095, 1086M, W2, W1 etc, i think the most important thing is a long soak time, which should be no problem with your set up.

 

my heat treating setup is very low tech, so i generally try to soak just over non mag for a minute or two, and then bump up the temp around 50f - 75f just before the quench, which is the only way i can get a hamon in oil on these steels. without clay, after three normalisations, if i bring it to just above non mag, and quench straight away in warm oil, it'll harden about 1/3rd of the blade; if you're not using clay, then depending on your normalizing you'll probably still get a differential hardness in oil, and if you polish and etch for it you'll see some kind of transition line, but for viking pieces this seems to have been common.

 

as for the size of the quench tube, 4 -6" diameter should do you fine, and a few inches longer than your blade - i use two or three malt whisky tubes taped together sitting in a jug and filled with old veggie oil, when i have to jerry-rig something for longer blades, and it holds up fine for my purposes, although it's obviously not ideal - the greater the diameter the more efficient the heat transfer, and peanut or canola oil should be faster than veg.

 

So the oil doesn't heat up too much and keep you safe - figure a gallon of oil pper pound of part. Anything more than that and you will be fine. I would look at having agitation running up the length of the tube - will do wonders to keep the vapor phase down and get a nice even quench.

[Michael Pikula]

Thanks for the info Jake, I have two forged out tanto's so I'll try quenching on in salts to see if it hardens or not. I'll try soaking at 1450F for 10 minutes and then quench when the temp starts to go down from the last "burner on" cycle and see if a file will bite after cooling to room temp. I'll try to keep the low temp at about 380F, it can be tricky at times to go cooler then that.

 

If the blade is straight after the last normalizing there shouldn't be any sori if you quench point first into a standing tube should there?

I have very limited knowledge about quenching into water but why would a double edged piece be asking for trouble in a water quench?

 

A bit off topic but if you clay up a blade and air dry for a couple of days and "cook" it at 400F for 4-5hours could you use salts to bring the piece up to temp or is there a high probability for danger?

[Howard Clark]

I heat the clay for 10 minutes at 600f in a pre-heated kiln, from wet, and then austenitize in high temperature salt with no problems. Satanite with finely ground charcoal.

 

Jake is right, IMO, I would not do that in water either.

[Michael Pikula]

Thanks for the pointer Howard, I'll try claying up those tantos and quenching one into the low temp and see if I get enough hardness for the file to skate, if all works well then I'll proceed with the sword. I'll post some results when I get them.

[Michael Pikula]

I set my temp for 1475F and gave the blades a 8-10 minute soak, they were quenched in 338F low temp and the tanto hardened very well. I tried doing a edge only quench in water on the other tanto and that didn't work out to well. But I quenched the sword in the low temp as well and it hardened as well except I felt a wobble about 2/3 of the way in... the salts had started to become slush further down the tube and pushed the tip off center and I got a nasty warp! Well I'll temper for 3 one hour cycles at 450F and try to straighten it out, I got some of the warp out after quenching but didn't want to push it since the blade was cooling off.