Forging Ahead

We just spent a weekend with about 200 youth on a pioneer trek.  It was amazing.  (More to come on that subject.)  In preparation, I decided to finish building a knife that I had started with the scouts.

I had three basic things to do on this knife to prepare it for the rigors of trekking:

1.  Harden the blade

2.  Attach the handle

3.  Build a sheath

The most tricky part would be hardening the blade, as I do not have ready access to an asedaline torch.  Here's how I did it:

I dug out a little propane torch and tried to warm the blade, but I couldn't get it hot enough.  Then, Monday night I had a thought to use briquettes to keep it hot while I moved the torch flame up and down the blade.  I discussed this with a co-worker who does some forge work, and he suggested setting up a blower to stoke the coals. 

Essentially, I ended up with a mini forge that worked quite well!  Not pictured here is the coleman blower (for air matresses) taped to the pipe. 

I used my daughters' playdough for a quenching medium.  This was the messy part of the job.  I mixed the playdough with motor oil and then placed it in a groove I'd cut in a block of wood.  I added  more oil to the mix for good measure.  The idea is to mold the clay to meet the shape of the cutting edge so as to mainly harden the cutting edge, yet keep the back edge somewhat ductile.  (I'll now refrain from a discussion on the properties of steel and phase diagrams.)

I used the torch a little, but eventually abandoned that, because the coals were doing quite well at warming the blade.  As soon as it was red hot, I pulled it out and quenched it.

I loved seeing the smoke roll off with the quench, but worried what people walking by might think about the column that was rising from behind my fence.

Here's the knife and sheath after use on the trek.  It held up well for the three days, although it took me over an hour to re-sharpen it after it was used to chop carrots on a cast iron cutting board!  I did cringe when I saw that happening, but afterward, I was not afraid to play Stretch (a game requiring throwing the knife into the dirt) with it.