temper a blade without an oven?

[WalterDavis]

I was just curious, how would a smith temper a large blade without a temperature-controlled oven? Maintain a constant temperature near to the forge and let the blade set there, or is there something else obvious that I'm overlooking? I ask partly because I'd like to make some larger blades (machete, short-swords) but don't want to bring them into the house, and partly just curiosity how it could be done, especially in a primitive setting without electricity or gas

Thanks,

Walter

 

[koyote]

I just did a large blade and popped it in the home oven - up on edge on top of the pizza stone tiles for good heat distribution.

If I were gonna do it without the oven, I guess I would try a smoker type setup, build a fire over here and run the chimney over thar.

You could always do the hod bard of steel drawing method and watch the colors real close and have a big water trough handy.

BUt I'm just sort of guessing here.

 

[bikermikearchery]

Sand the metal shiny. Lay the steel in your coals spine down Start pumping some air to the coals the steel will start changing color as the temp raises in the metal.
Pale yellow 420*
straw 470*
bronze 500*
purple 540*
dark blue 590*
Steel gray 650*
I would try to have the spine in the purple/blue range and the edge yellow/straw. It takes a well tended fire bed a good eye for color, and some luck.
Same thing to do it with a torch. just paint the color you want in to the blade.

 

[Stacy E. Apelt - Bladesmith]

I use my kitchen oven for large blades and swords. Put in a reliable thermometer to monitor the temp.
Stacy

 

[john0270]

Just use someones oven.... colors lie... or my temp sensor lies...

 

[AcridSaint]

If you're just looking for more "primitive" ways it can be (or has been) done, one interesting way to temper a file that I read about was to dip it in molten lead. Not exactly good for your health, but apparently it was the old "simple" way to temper a file because of the lead melting point. That's ~600F which would actually be a bit hot for us (or for files, imo), but maybe a person could take this idea and run with it, finding a solid that melts at their tempering range.

I read a very good book a while back on google books, very interesting to see how these things were done "old-school". Have a look here:
http://books.google.com/books?id=NJkBAAAAYAAJ&printsec=frontcover#PPA87,M1

Make sure and read P88 as well.

I wanted to add that these techniques are all done with very simple steels, this book was only written 30 years or so after Mn. was introduced into tool steel, I believe. Colors would not work the same with something like 5160.