Annealing thin steel & etc.

[W T]

More Noob questions...

Great looking at all you knifemakers' craftsmanship & especially interesting to see use being made of 'found' materials. Liked that little patch knife made from a length of steel strapping.

Got a couple of worn-out larger Skil saw blades and I'm wondering how to draw out the temper to a workable softness - have had those things snap and shatter. Must they be slow-heated to red in a forge or can a careful and slow heat get properly built-up with a torch without burning them out?

Also seeing a lot of posts about using good-quality files and leaf springs for forging - anyone ever use a hunk of lawn mower blade?

Thanks to all at this tremendous site - I've gotten about three hours sleep since finding you all a couple days ago

 

[LRB]

Mystery steels are not wise to use, although many do. It is always best to know what steel you are working with to get your best heat treat, and to know what to expect for your efforts.
To anneal steel, it needs to be heated to a red orange, then cooled as slow as possible. There are many ways of cooling it. I used to like to bury it in vermiculite with another heavy bar of red hot steel to retain the heat even longer, but you will hear of a dozen or so different ways to do this. Most all will work, just some better than others. Some steels, especially files, will anneal enough to work them by just heating red orange, and letting them air cool.

 

[W T]

Thanks - think it was your posts that got me onto this.

Have totally 'cooked' thin steel on a grinder alone before - looking not to screw up!

 

[LRB]

I'm not sure of what you just posted, but thin steel can be a problem to anneal without a heat treat oven, or a kiln. I use an oven. I can bring the heat to where I need it, then just turn it off, and the next day remove the steel fully annealed. A way for you to do thin steel, would be to sandwich it between two pieces of heavier steel, wrap with wire and bring the sandwich up to a red orange, then shove it into a 5 gal. bucket of vermiculite and let it cool for a day.
As far as cooking the steel on a grinder, if you mean overheating it while grinding, this is not a problem as long as you are going to heat treat afterwards, which is the normal way of making a blade. If you are trying to grind treated steel, you just have to go very slow, and keep it below aquireing colors. Grind a few seconds and quench. Grind bare handed so that you know when it is getting hot. I started that way myself, but it takes a long time to do it. Don't get discouraged with all this, you can do it if you are determined. Knowledge, patience, and determination will usually overcome any obstacle.

 

[W T]

Thanks - meant to say that your posts got me thinking in detail about the problem of annealing very thin steel to a workable state.

Annealing/tempering/hardening are all voodoo to me, but after reading thru dozens of pages in this forum, the processes looked doable, but not without a forge of some kind to properly get the material up to annealing temperature.

So if, for instance, I wanted to make a very thin, one-side-beveled little patch knife out of a larger-size Skil saw blade, it looks like the only option is to try slow grinding to remove the teeth and rough-out the shape.

By 'cooking', I meant that I have been amazed at how quickly the temp will build up in a screwdriver tip being reshaped with a grinder running at too-high RPMs.

I thought that perhaps first slowing running a Mapp gas torch flame over thin steel & trying to heat it up enough to lose some of its hardness might be effective, but I guess not. So I'll try slow grinding and frequent cooling dips - and try to keep my fingers out of the way.

 

[chipper]

Here's a cheap way to anneal even in the winter time outside.
I use my forge with charcoal to heat up a couple of big flat pieces of steel. At the same time I have a huge popcorn tin that's filled with white ash from my BBQ'er. Once the steel is red hot, I bury them in the ashes, side by side with a few inches of ash in between. I then Heat the steel, until it's non magnetic. I use a magnet on a piece of wire to test if it's non magnetic or not.
Once it's hot enough, I stuff it in between the two hot pieces of metal and ash. The next day it will be cooled off and ready to work.
I've had pretty good luck using circular saw blades for all kinds of knives, all though the stuff is generally pretty thin. Lawn mower blades work great too, especially for throwing knives. Once you've worked a bunch of material like this, you'll get dissatisfied with the results and start buying the good stuff. Wick pestered me until that's what I did. In the end he's right. I use 1/2" W1 Drill rod for most of my knives, It's really cheap. Like $6 for 6 feet. It's tough at first to make knives out of it because they are difficult to heat treat, but they are great knives when your done. My favorite stuff to work now is truck coil springs. They are really easy to get for free and make a great knife. Very easy to heat treat.

Well, good luck.
There's nothing better than making something for nothing and then selling or trading it for rondezvous stuff.

Regards
Loyd Shindelbower
Loveland Colorado

 

[BillinOregon]

Loyd, you (and Wick) are probably right about using decent, known steel. I've mostly fiddled with old files. Have a couple of lawn mower blades that are probably more trouble than they are worth. I do have a chunk of an old misery whip crosscut saw that should be good stuff if I can anneal it enough to get some pieces off of it. Leaf springs of 5650 are one of Tim Lively's favorite sources for knife stock. But I really ought to just order some good stuff and be done with it.