I have been having problems with heat treating and wondered if one of yall could help.
My main blade material is high carbon 5160 steel from leaf-springs.
Since I am only 13 and on a micro budget, I don't really have the funds to go into all these different kinds of oils, so to keep things simple I have been tying to use water. I am used to using old engine oil but I ran out so I am having a considerably hard time switching to water. Anyway, to get to the point, the process I use is this.
1. Forge blade to shape.
2. Grind edges smooth.
3. Hand sand with rough rock (so I can see heat treating colors better).
4. Stick blade back in forge wait till evenly cherry red, then air cool to assure softness (annealing)
5. While blade is cooling build up allot of hot coals on bottom of forge, putt pipe on top of these coals, putt more coals on top of pipe so you have a evenly heated pipe.
6. When blade is cool insert it into the pipe(the evenly heated pipe will evenly heat the blade).
7. When blade is evenly cherry red take out and grip firmly with pliers.
8. Rock blade back and forth so just the very edge is in the water, therefore quenching only the cutting edge leaving a soft back.
However, this is where the problem is, when I go to test the quench by filing the edge I find that the the edge is like I had only annealed it. 
Any help would be great.
Jonathan Stanley
Apprentice Smith
Hello Johnathan. Well you could use water, BUT, you are liable to hear the dreaded tink sounds as the blade cracks. If you can get some vegetable oil or canola oil, these work fine for 5160.
My steps for 5160 are:
1. Forge to shape
2. Thermal cycle
By this I mean relieving stress and grain reduction. I usually do
it twice. The first time I bring the blade up to just past critical
temperature, approximately 1500 degrees. You can do a test with a
magnet on the heated blade. When the blade becomes non-magnetic you
are near the critical temp. Allow the blade to go slightly above
this temp, then air cool until no color remains. I do this a second
time at just non-magnetic. Then I will heat the blade to just under
that non magnetic point and place the blade in vermiculite to cool.
You can use wood ash also. I let the blade stay there overnight.
3. Rough grind the blade to 120 grit.
4. Your pipe method is good, but also use the magnet to check your temp and not just your eye. Let the blade go just above non magnetic and hopefully hold it at this temp for a minute or so. Then quench in 100-130 degree vegetable oil. I also will check the edge with a file.
5. Clean blade of quenching junk back to 120, then into the tempering oven at 400 degrees for two hours, allow to cool then repeat the two hour cycle.
I hope this helps somewhat. You can try water, but I would suggest warming it to 90 degrees or so before quenching. Good luck.
Brion
Brion Tomberlin
Anvil Top Custom Knives
ABS Mastersmith
Sounds like you may not be getting it hot enough. You could do some experiments on some scrap pieces too.
Go by the local McDonalds and talk to the manager and ask if you could have some of their old french fry oil , that would be better than the water.
9-11-01 , We Will Never Forget.
Work smarter NOT harder
I wouldn't recommend water. I've been using canola oil for years with great success.. Costco sells large quantities.. As Dwane mentioned, you might be able to pick some up from a restaurant. Good luck..
WOW!! <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//smile.gi f' class='bbc_emoticon' alt=':)' />
Thanks for the advice. <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//smile.gi f' class='bbc_emoticon' alt=':)' />
I think I will try your process Mr. Brion. <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//smile.gi f' class='bbc_emoticon' alt=':)' />
As for the oil....... Thanks for advice Mr. Dwane, I think I'll try McDonald's (and get some french fries while I'm at it) <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//wink.gi f' class='bbc_emoticon' alt=';)' />
Jonathan Stanley
Apprentice Smith
