Home heat treating blades

[nickg]

Can anyone help. Im thinking of making a woodlore type full tang knife from scratch. I'm OK with shaping and grinding the bevel etc but i could use some help & advice on heat treating it. I'm using 01 steel but have only access to DIY type heating equipment ie butate soldering torch a la B&Q. Is heat treating viable and what is the best type of quenching medium etc. In fact do I need to heat treat tool steel anyway. Appeciate any help & advice.

Nick

 

[Simca]

On knifeforums.com there is a newbie knifemaker section, where i found this very good beginner tutorial: http://hossom.com/tutorial/jonesy/

 

[Ogri the trog]

Nick,
Do a search for Greenpete, he's a member here with his own website containing advice on home knife making... that and he a very nice bloke anyway.

ATB

Ogri the trog

 

[C_Claycomb]

I would offer advice, but really I am still learning, so thought I would put my sources of information here. There is tons of information on the various forums covering every aspect of knife making.

Bladeforums:
http://www.bladeforums.com/forums/forumdisplay.php?f=789

Knife Network
http://www.knifenetwork.com/forum/index.php
and tutorial section
http://www.knifenetwork.com/workshop/index.shtml

www.britishblades.com

If you try search strings for Heat Treating (don't bother with "O-1" its too short a word) you will find loads of info.

More than you probably want to know but.....
http://www7.taosnet.com/ebear/metal/heattreat0.html

Bob Engnath's page
http://www.engnath.com/public/manframe.htm

I would also recommend Wayne Goddard's book $50 Knife Shop.

This is the heat treat set up I used for a while. I basically use the same one still, only now it is in the garage

The B&Q torch pictured did a fine job, but I used a soft fire brick to contain the heat, I couldn't get to critical temp without that containment. There is information on the One Brick Forge over on Britishblades, and other forums for sure.

BEWARE, KNIFE MAKING CAN BE ADDICTIVE AND HAVE A DAMAGING AFFECT ON YOUR BANK BALLANCE

 

[dtalbot]

Two suggestions, if you want a spot on service and don't mind spending a fiver or so go over to British Blades and look up the HT service offered by Shing.
Second suggestion, a bit more rough and ready but works fine, find someone with a solid fuel aga/rayburn cooker. The fire box runs plenty hot enough to HT a simple steel like 01 (I do my HT in the cooker) just be careful, leave it too long and you will have it to forging temp!

 

[Greenpete]

Can anyone help. Im thinking of making a woodlore type full tang knife from scratch. I'm OK with shaping and grinding the bevel etc but i could use some help & advice on heat treating it. I'm using 01 steel but have only access to DIY type heating equipment ie butate soldering torch a la B&Q. Is heat treating viable and what is the best type of quenching medium etc. In fact do I need to heat treat tool steel anyway. Appeciate any help & advice.

Nick

Hi!
Maybe my site will help you?
http://www.greenpete.co.uk/knife_making/knife_making.htm
Pete

 

[Shing]

I think a blow torch is a lttle small to heat treat a Woodlore size blade assuming its 4mm thick and 100mm long. A charcoal fired barbie might work although the last time I tried the blade warped because of the uneven heat and got lots of pitting on the blade due to excessive oxidation.

Best bet is a coal effect gas fire, a gas fired barbie or like dtalbot says a Rayburn/Aga solid fuel cooker. You can use any oil to quench like veg or sunflower but not any thing from a car like old engine oil since it might contain some petrol residue!

 

[nickg]

Shing I hadnt thought of the barbie idea. I assume you mean the type with lava 'coals' over a gas jet. Whats the technique? fire it up, get it hot, lay the metal onto the coals till it gets to a dull red and then quench in oil? - i assume that a butane/propane torch would do to draw the temper after.?

 

[Greenpete]

I think a blow torch is a lttle small to heat treat a Woodlore size blade assuming its 4mm thick and 100mm long. A charcoal fired barbie might work although the last time I tried the blade warped because of the uneven heat and got lots of pitting on the blade due to excessive oxidation.

Best bet is a coal effect gas fire, a gas fired barbie or like dtalbot says a Rayburn/Aga solid fuel cooker. You can use any oil to quench like veg or sunflower but not any thing from a car like old engine oil since it might contain some petrol residue!

I know for a fact that 'tempering' a woodlore sized knife with a blow torch not only works but is ideal! After all I have made a few that way!!
The hardening is done in the forge (as opposed to with the gas torch).
As for the oil, old engine oil is exactly what I use and it works fine!
Petrol residue?? What do you mean? Petrol evaporates far too easilly to still be hanging aroung in the engine oil, and even if it is....whats the problem?
As for veg' oil I don't know as I haven't tried it but I wouldn't bother trying as I personally don't think it would be as good.
Have you ever made a knife Shing?
Pete

 

[dtalbot]

I know for a fact that 'tempering' a woodlore sized knife with a blow torch not only works but is ideal! After all I have made a few that way!!
The hardening is done in the forge (as opposed to with the gas torch).
As for the oil, old engine oil is exactly what I use and it works fine!
Petrol residue?? What do you mean? Petrol evaporates far too easilly to still be hanging aroung in the engine oil, and even if it is....whats the problem?
As for veg' oil I don't know as I haven't tried it but I wouldn't bother trying as I personally don't think it would be as good.
Have you ever made a knife Shing?
Pete

Take a look on BB and you will see Shing is one of the best custom knifemakers in the land. Veg oil works fine and for an indoor setup like my rayburn or a gas fire has the advantage of just smelling like cooking chips!
Cheers
David

 

[nickg]

Thanks everybody for all the pointers. Ive just spent hours looking through all the links etc.
one possibility occours to me that instead of hardening the whole knife and then drawing the temper on the spine Perhaps I could try differential hardening on the edge alone leaving the spine relatively soft. It might be easier to control the heating with a torch just on the edge.

 

[C_Claycomb]

Actually, for a bushcraft knife, using a torch to only bring the cutting edge to critical isn't a good idea. It leaves the spine too soft to work really well on a fire steel. I haven't actually tried that, but have talked to people who have, and read plenty of reviews/comments to that effect.

Edge quenching will give a similar result, but give you the option of making the spine harder.

Also, if you only heat the edge, you need a certain amount of thermal mass to retain the temperture. Ed Fowler uses an oxy-acetyline torch to just heat the edge, but he leaves the edge really thick and does a lot of grinding on the hardened blade.

 

[Shing]

I used the use the coal effect gas fire in my lounge to do heat treating much to the disapproval of SWMBO. I put the blade in when the fire was low and had to get the fire really hot to get it to critical temperature. I haven't use a gas fire barbie but the situation is similar. Put the blade edge down, slowly raise the temperature and get it to a bright orange, you can check it with a magnet, often, when it dosen't stick its at the right temperature, do it in the dark to get a better view of the colour, its more difficult in day light or strong light. Plunge it quickly into oil tip first and vertically and submerge it for at least 30 seconds to get most of the heat out. Clean off the oil and quickly clean off the scale with emery paper and test it with a dull file. If the file bites into it, try filing a little more, sometimes the surface is soft because the heating cause loss of carbon but file a few more times and if the file skids off, its harden, if not anneal and repeat the whole process. To temper, you can put it into a ordinary oven at 220C for an hour, let it cool in air and repeat or you can do colour tempering by cleaning all the scale off one side of the blade, heat it carefully with your blowtorch, get it to a mid straw colour, let it cool in air, clean the other side and repeat to double temper it. The reason why I warn about using old engine oil is it might contain heavy petrol residue which might cause a flash fire and veg oil is cheap, safe and dosen't stink your workshop out but to each his own.

Some knives I made earlier

[url]http://www.britishblades.com/photopost/showphoto.php/photo/687/cat/500/page/1[/url][img]

[img][url]http://www.britishblades.com/photopost/showphoto.php/photo/499/cat/500/page/1[/url][img]

[img][url]http://www.britishblades.com/photopost/showphoto.php/photo/965/cat/500/page/1[/url][img]

 

[nickg]

I used the use the coal effect gas fire in my lounge to do heat treating much to the disapproval of SWMBO. I put the blade in when the fire was low and had to get the fire really hot to get it to critical temperature. I haven't use a gas fire barbie but the situation is similar. Put the blade edge down, slowly raise the temperature and get it to a bright orange, you can check it with a magnet, often, when it dosen't stick its at the right temperature, do it in the dark to get a better view of the colour, its more difficult in day light or strong light. Plunge it quickly into oil tip first and vertically and submerge it for at least 30 seconds to get most of the heat out. Clean off the oil and quickly clean off the scale with emery paper and test it with a dull file. If the file bites into it, try filing a little more, sometimes the surface is soft because the heating cause loss of carbon but file a few more times and if the file skids off, its harden, if not anneal and repeat the whole process. To temper, you can put it into a ordinary oven at 220C for an hour, let it cool in air and repeat or you can do colour tempering by cleaning all the scale off one side of the blade, heat it carefully with your blowtorch, get it to a mid straw colour, let it cool in air, clean the other side and repeat to double temper it. The reason why I warn about using old engine oil is it might contain heavy petrol residue which might cause a flash fire and veg oil is cheap, safe and dosen't stink your workshop out but to each his own.

Some knives I made earlier

http://www.britishblades.com/photopost/showphoto.php/photo/687/cat/500/page/1

http://www.britishblades.com/photopost/showphoto.php/photo/499/cat/500/page/1

http://www.britishblades.com/photopost/showphoto.php/photo/965/cat/500/page/1

Thanks shing I have looked at your stuff on bb forum and you have turned out some great looking knives. I will try the gas barbie as this is the most accessable equipment for me, followed by the oven to draw the temper.
When you quench in veg oil does it ignite the oil or just make it smoke, Im wondering how fussy i need to be about the container.

 

[ESpy]

As for veg' oil I don't know as I haven't tried it but I wouldn't bother trying as I personally don't think it would be as good.

Depends on how fast a quench you want. I prefer veg oil to engine oil, but whatever works for you. I'd use peanut oil (higher flash point) if it wasn't so expensive. Even water will work if you're careful with the steel, which is handy if you've forgotten your quench bucket for a demo

Have you ever made a knife Shing?

Shing's made more than me at the last count, and they're very good

 

[Ogri the trog]

Chris Claycomb,
I hope you get to read this thread again.
DO you mind if I ask where you got the fire/refractory bricks from to make the table-top furnace in your first post in this thread? I'd like to do something similar and only need a few bricks to work with.

TIA

Ogri the trog

 

[Martyn]

I think a blow torch is a lttle small to heat treat a Woodlore size blade assuming its 4mm thick and 100mm long.

I know for a fact that 'tempering' a woodlore sized knife with a blow torch not only works but is ideal! After all I have made a few that way!!

Heat treatment is the process of hardening and tempering, not just tempering. If you've managed to harden a 4" blade with nothing but a propane torch, I'd love to hear how?

As for the oil, old engine oil is exactly what I use and it works fine! Petrol residue?? What do you mean? Petrol evaporates far too easilly to still be hanging aroung in the engine oil, and even if it is....whats the problem?

If you put a cherry red piece of steel into petrol you get fire - rather a lot of it.

As for veg' oil I don't know as I haven't tried it but I wouldn't bother trying as I personally don't think it would be as good.

Why not? Veg oil is the quenching medium of choice for many professional custom knifemakers both here and in the US.

It is possible to heat treat (harden) a knife with a B&Q propane blowtorch - using the assistance of a dugout refractory brick. It's affectionately known as a "one brick forge". You do need the refractory enclosure though. Without it you wont get the steel hot enough over it's whole length. The "one brick" is abpout the cheapest way to get a forge hot enough to be capable of hardening and forging steel.

here are some examples...

http://www.britishblades.com/forums/showthread.php?t=3821

http://www.britishblades.com/forums/showthread.php?t=10800

Tempering can be done in almost any domestic oven.

Have you ever made a knife Shing?

That ranks right up there with "...so Mr Mears, you ever done any camping?".

 

[C_Claycomb]

I am afraid that I got my bricks in a rather hit or miss manner. The ones in the picture came from a brazing station in my old factory, the place was being knocked down and various treasures were to be left behind. I got a few more by looking under Refactory Engineers in the Yellow Pages. There aren't many such people around, the old boy I contacted was actually retired, but had a supply of stuff he wanted to be rid of.

Really the simplest thing for you to do is go over onto British Blades and do a search for "Fire Bricks". The following is one of about 20 threads to be thrown up:
http://www.britishblades.com/forums/showthread.php?t=8672&highlight=Fire+bricks

There are a number of links in there to places where people have bought bricks.

Sorry I can't be more helpful

 

[Greenpete]

Heat treatment is the process of hardening and tempering, not just tempering. If you've managed to harden a 4" blade with nothing but a propane torch, I'd love to hear how? If you put a cherry red piece of steel into petrol you get fire - rather a lot of it. Why not? Veg oil is the quenching medium of choice for many professional custom knifemakers both here and in the US.

It is possible to heat treat (harden) a knife with a B&Q propane blowtorch - using the assistance of a dugout refractory brick. It's affectionately known as a "one brick forge". You do need the refractory enclosure though. Without it you wont get the steel hot enough over it's whole length. The "one brick" is abpout the cheapest way to get a forge hot enough to be capable of hardening and forging steel.

here are some examples...

http://www.britishblades.com/forums/showthread.php?t=3821

http://www.britishblades.com/forums/showthread.php?t=10800

Tempering can be done in almost any domestic oven.



That ranks right up there with "...so Mr Mears, you ever done any camping?".

Lol what a thread this is turning out to be! Where to start?
Shing....Mears camping...I've heard of Mr Mears never Shing, that's just the way it is... we can't know everyone, can we?
Heat treat...yes covers both hardening and tempering, and no I haven't hardened a knife with a gas blow torch...I never said I had!
I also didn't say you shouldn't try veg oil I merely said I didn't think it would be very good....I will try it as it has been pointed out so many times that it is!
And of course you get fire if you put a cherry red blade into petrol, you also get it if you put it into oil in my experience! I have never said you should, just that a little residue doesn't cause any problems.
Maybe we're all getting a few wires crossed, including me. I originally read a post by Shing that didn't seem quite right from my experience.
He also posted directly after me criticizing techniques I have explained on my site, I felt it necessary to clear some things up being as the idea of my tutorial is to show ONE easy way to make a Ray Mears style knife.
You gotta laugh at the pride and ego we all seem to have!