Homemade tools

[buddyellis]

I'd initially posted this in one of the other thread, but thought the better of it, as it probably shouldn't clog up that discussion.

Here's the first one I made, from a piece of a coil spring I unwound. I needed something to clean a purfling slot on a violin I am building. It's a bit too long after the 'leg' but it works pretty darn good for free. POS pecan handle turned on my drill press. Notice my 'forge' (cheap propane torch) and my quench bucket (coffee cup) in the background http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif I guess this should be in a new thread.

[buddyellis]

#2 I'm started working on, from some rod steel from lowes. This stuff isn't hard enough which is why I've started toying with concrete nails. It's in rough form, and pretty much abandoned, although it is pretty darn sharp.

[Antlurz]

On the real small ones, a shank from a decently good drill bit is great, and you don't need to do any tempering or heat treating as long as a straight shaft will work.. Screwdrivers from the dollar bin will work too. They are usually hardened all the way up to the handle.

That strapping they use to band stuff together can make some interesting small knives.

Lots of "possibles" if one like to tinker and make their own tools. Old handsaw blades are the makins' for some good scrapers.

Ron

[ErikAitch]

Here's my tempering trick... can't recall who I stole it from, but it works a treat:

Once it's hardened and cooled, lay the tool on a piece of scrap steel and put the whole mess in the toaster oven. Heat in stages to the desired temp depending on the steel, checking with your digital oven thermometer, hold at temp for about 20 minutes, then ramp the temp down slooooooowly.

The hard part is figuring out what your steel wants to be tempered to... too cool and it's brittle, too hot and it won't hold an edge.

[sunburst]

...then ramp the temp down slooooooowly.
Correct me if I'm wrong here, but here's what I thought:

-To anneal a hard piece of steel, heat it to "cherry red" and cool it veeerrryyy sloooowly.
-To harden a piece of steel, heat to cherry red and quench it to cool it rapidly.
-To temper the hardened steel, heat it back up to the temperature that gives the desired hardness, and cool quickly or slowly, it doesn't matter.
-Different steels need slightly different handling for reliable results.

BTW, I've annealed old files to the softness of plain iron by putting them in a wood fire, leaving them there 'til the fire went out, and letting them cool in the pile of ashes over night or longer.
I've tempered hardened steel in the kitchen oven.

[Stephanie Reiser]

Great job on the dog-leg chisel, Buddyellis. Really nice.
One of my handiest homemade chisels is a really narrow one fabricated from a broken needle file, simply reground to its new shape then inserted into a handle made from scrap curly maple.
When tempering, I like to draw back my paring chisels to a peacock color, as opposed to a straw color that you might use for a tool receiving harder use such as a hatchet.

[buddyellis]

Stephanie:
Yea, it's interesting thing to study! I never previously (before I started messing with this stuff about a month ago) made the connection that the colors the metal changes have fairly specific heat ranges and that in watching those colors, you can get a pretty good idea of the temperature of the metal. There's no more magic to this than anything else, and this technology, for the most part, is hundreds (thousands?) of years old. We just have the benefit of MUCH better available steel these days.

For these small chisels, its not like we are going to be mortising in oak, or some such, with a hammer. They are somewhat delicate tools for delicate work, and as such can realistically be a bit harder (at the cutting edge) than something to be used for strenuous work. I pull my stuff to a good blue, too.

John: good trick on annealing. Toss hard stock in a grill, or something, and let the fire burn out!

[Stephanie Reiser]

Just remember something that Joseph Moxon said mid-eighteenth century: "Heat that wood a good strong wind; must forge thick, and grind thin."
In other words, get the shape in the ballpark on those small chisels with the hammer and anvil, and then fine-tune the exact shape at the grinding wheel (but don't burn the steel).

[sunburst]

"Heat that wood a good strong wind; must forge thick, and grind thin."
I can attest to that too. I ground a nice, thin, hollow ground knife blade before hardening it.
Even if it hadn't cracked, it was far to ripply to be any good!
My limited early experiments with blacksmithing taught me several things, among the most important of them; 1. "release" the hammer when it strikes, and 2. tendinitis takes a long time to heal.

[amowry]

I learned that the hard way, too. One of the first knives I made is full of hairline cracks. Looks kind of cool, though, almost like damascus.

[ErikAitch]

...then ramp the temp down slooooooowly.
Correct me if I'm wrong here, but here's what I thought:

-To anneal a hard piece of steel, heat it to "cherry red" and cool it veeerrryyy sloooowly.
-To harden a piece of steel, heat to cherry red and quench it to cool it rapidly.
-To temper the hardened steel, heat it back up to the temperature that gives the desired hardness, and cool quickly or slowly, it doesn't matter.
-Different steels need slightly different handling for reliable results.
You're not wrong at all for tempering with a flame. There, the need for a rapid quench is to stop the heat from rising beyond the desired point, and by starting the heat at the handle end of the tool you get a softer shank than the edge. Which is a good thing for larger tools, as it acts as a bit of a shock absorber.

With very small tools, though, it's hard to control as the heat travels quickly but less predictably. Quenching small tools evenly is also difficult, and imparts stresses I'd prefer to avoid.

Tempering to a specific heat and cooling slowly allows much greater control of the temper while reducing unwanted stresses. It also eliminates the possibility of burnt edges, which is all too easy to do when flame tempering.

Am I making sense?

[Antlurz]

Another thing that should be mentioned. When heat treating by color, you should work in low light. In fact, the darker the room, the better, within reason. The color you perceive in the metal looks totally different in a well lit room or outside than it does in a darker room, giving you a less than accurate indication of the actual color.

Ron

[Stephanie Reiser]

With very small tools, though, it's hard to control as the heat travels quickly but less predictably. Quenching small tools evenly is also difficult, and imparts stresses I'd prefer to avoid.

Tempering to a specific heat and cooling slowly allows much greater control of the temper while reducing unwanted stresses. It also eliminates the possibility of burnt edges, which is all too easy to do when flame tempering.

Am I making sense?
With small tools or even tiny steel springs I usually heat on a bar of iron in a coal forge and then quench in molten lead. This usually works well with "found" steel, or scrap. If you purchase your steel from a supply house, it generally comes with intructions for annealing, hardening, and tempering. Some steels are water-quenchable, while some are oil. I have found that old files harden most successfully in automatic transmission fluild. When working with scrap, your control of the hardness is for the most part seat-of-the-pants, so to speak. Which is also half the fun.

[dstretch]

Here is my contribution to homemade tools. First a story. I was just about to have my wife convinced that I needed a performax 16/32 thickness sander, or should I say conviced not to kill me as I slept if I bought one. So I banged my head thinking how can I thickness my sides evenly and keep her happy. So I searched and found some ideas and here is the outcome. I am proud of it, and man it works like a charm.

[dstretch]

Another picture. With a nice piece of curly maple from Bruce at OrcaIsland. I think I can get about 4 complete rib sets out of it.

[dstretch]

And here is the side being shaped.