First Full Length Sword

David Stifle

David Stifle

Joined
Nov 20, 2008
Messages
10,188
Hi Guys,

Well, after 6 years of knife making, I finally made my first full lenght sword, a 25' cutting edge, OAL 34". Now, I can heat treat, and quench okay, but I can't figure out how to temper it. Does anyone have any suggestions?

Thanks,
Dave
 
Hi Nathan,

(Sigh) I knew you say that! But I'd rather wait until it is finished, or at least Ht'ed and sanded down to better show the grinds before posting. So, in a week or so, okay?

How did the old timers temper long blades? I doubt they had big ole ovens, but maybe they did, it's just that I don't. I suppose I could send it out, there's probably bladesmiths who could do it.

Thanks

Dave
 
How about a 40" long piece of steel (or box of sand) on top of a kitchen stove across 2 burners?

Heat slowly until the plate or sand is stable at the temp required, then put the blade on it...

similar to the idea of tempering tongs...
 
I'm just bustin chops, David. But we DO expect pictures when it's done :D.;)

Or along the lines of 1-10's idea, a linear fire pit with a long piece of sand-filled channel iron on it. You'd have to monitor the temperature and adjust the fire some....the oven burner idea may be easier. If you're worried about a cold spot between burners, you can always shift the swords position after a while.

From what I've read in the past, people have put the sword in their oven oriented corner-to-corner with the tang sticking out the side of the door. Do several tempers and reverse the sword position and repeat.

--nathan
 
Well, you guys may be on to something. I was thinking about making a fire pit, similiar to the type of pit Islanders use to roast pigs, and burying the blade in it. Of course, it's a wild A**** guess as to the temp. But I bet it wouldn't be much more than 400 degrees. Could use several oven thermomoters placed in various spots.

I will most certainly post pics, guys.

Dave
 
You could take it to your local pizza place and bribe the kid at the counter with a $20 to let you use the oven for an hour.
 
Invest in a small drum of marquenching oil.

Weld a piece of steel pipe about 4" dia onto a nice stable base plate, wrap the outside with some insulation and heat from the side, at the bottom with a low pressure gas torch.

You can buy a thermocouple set up for about $40 from ebay,

The oil will heat real evenly and you can get it to hold stable within a couple of degress.

The above sounds like a lot of hastle, but when you compare it to the dozens of hours in making a sword blade it is well worth it :)
 
if you need inexpensive thermocouples for zone monitoring, I have several hundred I have been selling for 5 for $25, you could set up an array on switches and switch the meter between them

-Page
 
David,
Remove the shelves from the kitchen oven and pre-heat it to 400-450F ( whatever your target is). Stick the sword in diagonally, from the front top corner to the opposite back bottom corner. If the tang sticks out the upper corner of the door, that is OK, the small amount of heat lost will not be a big issue. Move it to the opposite corner after 1/2 hour. Turn it around ( tang in, tip out) and put back for another 1/2 hour.Change corners. With the three turns, you will have tempered for 2 hours. Cool off and repeat. If you are unsure, do it a third time. This works well for long swords. Remember, you only need to get the entire sword at an even heat for the quench. Tempering can be done in parts because it is the max temperature any part gets to that converts the untempered martensite to tempered martensite. Once tempered, that part is done.
I have tempered full katana this way. I can't remember if it is Walter Sorrells or Wally Hayes, but one of them does the same.
 
Boy, you learn something new every day. I just never thought you could temper in parts. Thanks, Stacy!

Believe me, guys, I thought abought the pizza oven too.

Dave
 
For remove shafts and blades of hockey sticks, we had a piece of steel pipe with a heat gun at one end. It would heat up the entire length of pipe within a few degrees. Build your own setup for this using 48" of pipe with a heat gun at one end and aluminum tape holding the gun on.
 
If you honestly clean the blade very well, wrap it in foil the pizza place should be cool with it. tell em you'll take a large cheese to go with it :D

you could make the tube tank like John N suggest, but fill it with cheap vegetable oil, then heat with a driveway weed burner torch. Use your thermcouple or a cheap 0-500F infrared temperature gun.
 
I just dont get why you would use a high quality steel, spend a couple of dozen hours plus grinding it, chew your fingernails aiming for perfect even heat quenching temperature, then risk a potentially uneven, inaccurate tempering cycle for want of a few $ worth of oil, or risk having a quenched, brittle untempered blade knocking around for a couple of hours whilst you negotiate with Dominos for a slot in an oven with hot spots, cold spots and garlic breads that at best will be +/- 20c ?? :)
 
David,

I am intrigued; can't wait to see what you have made.
I really enjoy the style of knives you make.

Fred
 
why bother going with anything but the best? Go full out and drop 5000$ on 48" tall high and low temp salts :D
 
If one was to make swords regularly,building a low temp salt pot would be a good idea. The cost is not as bad as one might think. But a difficult and dangerous to move,48" tall piece of heavy equipment, filled with 400-450F molten salt is not something for your average home garage setup.

A simpler solution might be making a large electric tempering oven. It would basically be a long HT oven. It could be vertical or horizontal. Because of the lower heat, coil life and current draw should be much less of a problem. PID control would be easy. Maybe a circulation fan from a convection oven would make for more even heat ( or build your own version of a convection fan).
Heck, I might build one of these for my new shop next year. I already have the low temp salt pot parts made up and am just waiting for the shop space to finish building it and permanently install it.
 
Thanks Fred

I appreciate the sentiment, especially coming from such a great maker as yourself. John N., all I can say is when a guy moves into the large blades everything changes. I normally use a very large charcoal grill for my forge, but when I forged this sword I had to dig a trench in the ground, lay my air pipe in it, hook it up to my hand cranked air blower, got the fire going until it was howling, and then hammered away. I got a long piece of eight inch drilling pipe, cut it open along it's lenght, and then weilded both ends shut. This will be my quench tank. At this point, all I have is a forged and ground piece of steel that looks like a sword. I will be doing the heat treat and tempering this weekend. I can't wait to see how this comes out. The one thing I couldn't figure out was how to temper it. I've checked out the oven idea Stacy mentioned, and believe it will work. I have no intention of making swords on a regular basis, so no salt tanks for me. But, I wonder, how did the old timers temper swords? I mean, viking swords, Japanese swords, all famous, well used, and trustworthy. They must have had a reliable way to regulate the temperature.

Thanks Guys,

Dave
 
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