Thread: Ran the forge this afternoon

A few weeks ago I decided to try to make a knife from an old file. The end result wasn't the prettiest of knives, but it definitely got sharp. So sharp, in fact, that I cut myself with it and had to get three stitches in the pad of my left thumb. That was just a trial run so that I could see if I could get the heat treatment done with a home-built forge. This afternoon I started working on another file knife, and I'm shooting for a far more refined result this time. After heating it in the forge, I buried it in some wood ash. I'll start grinding on it in the morning, and I'll post more pics once it's roughed in.

This is a pic of the file that I'm starting with. I did some grinding on it before putting it into the fire.


And here's two pics of my home-build forge while the charcoal was heating up

thats so cool. I look forward to seeing the results as you progress. Thanks for sharing

]Here's what I've got so far. The blade has been rough ground then filed into final shape. As it stands now, it's been sanded up to 220 grit. Next step is to heat treat, but I think I'm going to Woodcraft to get some coco bolo wood to make a handle.

[ATTACH]95962[/ATTACH

Well, I tried to heat treat the blade, but I don't think I let it soak long enough..... or maybe too long...... regardless, it won't take an edge so I know I've done something wrong. I'll probably try again tomorrow afternoon. In the mean time, here's some pics of the forge running during my failed attempt at heat treating.





**EDIT**
After looking at the photos, I think I got the steel too hot. Should have stopped at red instead of yellow.... DOH!

There is a definite are to heat treating the steel. Keep at it I'm sure you'll get it correctly. Props to you for even trying!!

Yeah, it took three tries with the first knife I made. I was hoping that it would be easier this time, but I guess not. Oh well, it's no big deal since its so much fun

That is Waaaaay too hot.
A dull red is what you are shooting for. Reduce the airflow to decrease the heat. that will also give the blade a better chance to heat evenly.
And get a strong magnet. You can best identify the correct temperature by checking with the magnet. As soon as the blade is no longer attracted to the magnet, that's when you quench.

Originally Posted by Bruno

That is Waaaaay too hot.
A dull red is what you are shooting for. Reduce the airflow to decrease the heat. that will also give the blade a better chance to heat evenly.
And get a strong magnet. You can best identify the correct temperature by checking with the magnet. As soon as the blade is no longer attracted to the magnet, that's when you quench.

I knew you were supposed to heat it up until the magnetism went away. This is the first time I've read that this is dull red, not orange.

Do you quench in oil or water? If in oil, what kind?

I'm just adding to my survivalist skills. I may starve, but I'll be clean shaven.

I tried it again last night, and if anything, I made the steel even softer. Third time's a charm..... maybe

@Crotalus: I use vegetable oil to quench.

Oil or water depends on the steel.
In general if you have a piece of steel and you don't know how to treat it, first heat a sample to non magnetic and quench in oil.
If you can clamp it in a vise and break it, it is oil hardening steel.
If it bends, try again but quench in water and repeat the test.
It it breaks you have water hardening steel.
If it still bends, it is mild steel unsuitable for making edged tools.

As for the color at which this happens: it is of course a subjective thing.
What appears as dull red by daylight is not the same as what appears dull red at night.
Japanese smiths close all windows and doors in their workshop when determining the correct quench point, to shut out all other light.

Anyway, try the test I described above if you have a sliver of steel left. That will tell you if have good steel or not.
Also, if you have heated that steel past yellow for a long time, the surface might not contain enough carbon to get truly hard.
In that case grind away half a mm before trying to sharpen.