Toolmaking - Music wire chisel

[Oceaneer99]

Ray showed me a set of miniature chisels and scrapers that he made from music wire, and has posted a photo of the set as well (though I need to remember where he posted it).

I decided I would try making a 1/8-inch chisel.  I bought a piece of 5/32 inch music wire a while back.  Last night, I cut off two 6 inch lengths and heated each one to cherry red with a propane torch.  I allowed both to cool naturally in air.  This annealed the wires so that I could shape them with metal files.

The first length I filed flat on one side over about 2 inches.  I went almost to the centerline of the diameter, so that I would have the maximum width available.  I also filed the rounded sides to bring the width to 1/8".  I filed a bevel in the back, angling down to the future cutting edge.  I matched the angle to other chisels I have.  I'll measure the angle and report back.

I plan to shape the other rod to make a small gouge.

I will need to flatted the wires a bit in a few places where it will be mounted in a wood handle, to hold the finished tools firmly in the handles, but I haven't figured out exactly how I want to do that yet.  Most likely, I'll make a round handle from two pieces of wood temporarily glued together.  I'll separate the halves and carve a groove to hold the wire, then glue the wire and the handle pieces together with epoxy.

Of course, after the rough shaping, I'll need to heat treat and temper the tools, then do a final sharpening.

I'll post some photos of progress later.

Garet

[lastvautour]

I tried using a 2 inch nail to do a small gouge but could not get a good enough edge to do a good carving job. I never thought of heating it before sharpening it. The metal was too soft to attain  the necessary edge sharpness.

[Oceaneer99]

I'm not sure that nails use the right kind of tool steel, though they are fairly hard.  I once made a knife from an old putty knife, but could never get it hard enough, so probably it was just mild steel.  Old saw blades are apparently good (not the new-fangled bimetal kinds, though) for thin tools, and a friend who makes violins (and his own tools) recommended drill bits and drill bit steel for making small chisels.  The music wire seemed to work pretty well (it is actually the type of carbon steel they use for springs, I've been told), and I can get it at my neighborhood hardware store.

Garet

[Oceaneer99]

Lou, I did some checking on-line and found:

High carbon steel is used for cutting tools and masonry nails (nails designed to be driven into concrete blocks or brickwork without bending).

source: http://www.chemguide.co.uk/inorganic/extraction/iron.html

They said that ordinary nails are mild steel, which could not be heat-treated for tools.  So it appears you could use masonry nails to make tools.  However, I'd think the quality control on tool steel and spring steel is probably better than nail steel.

Garet

[Oceaneer99]

I have an excellent book on the subject of metalworking for toolmaking.  The Making of Tools by Alexander G. Weygers.

I did some more carving with the music wire chisel and decided I went too far with the tempering.  After some use in wood, the very end of the thin edge would bend back a bit, like a wire edge you get when sharpening.  I re-heat treated the metal and am preparing my oven for a 400 F temper, which should be a harder, light straw color.

Garet

[Oceaneer99]

That did the trick!  I put an oven thermometer in the oven and brought it up to 400 F, then put my very hard chisel in the oven for about 15 minutes.  The temperature stayed between 400 and 425 F, which is the range I wanted.  The chisel had a medium straw (yellow) color, but not the more bronze color it had before.

I honed the edge and tried it on wood again.  This time, the edge stayed clean and sharp.

I did try honing the untempered (but hardened) edge, but it was so brittle that the cutting edge was always left with a ragged edge, visible with a magnifying glass.  I guess that's why you have to temper tools.

I did hear some other ideas for sources of good steel to use for tools like this.  Masonry nails work, as do Allen (hex) wrenches.  My local hardware store has 1/4 inch Allen wrenches for about $1.50, though they are not that long.  I also found an article about making gouges from flat pieces of blade and bending the carving surface.

Garet

[Oceaneer99]

The chisel is finished!  I made a quick handle from some square birch stock that a friend gave me (thanks, D.M.!).  I drilled a hole all the way through, 1/64-inch smaller than the music wire.  Then I put the sharp edge of the chisel against a block of wood and drove the handle on to the other end using a mallet.  I was very worried that I'd damage something this way, but all went well, and the metal seems to be seated well in the handle.  The tang of the chisel goes all the way to the back edge of the handle, where I filed it flush.  This was a suggestion from Ray, in case I ever decide to tap it with a mallet.


http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-1068

The photo shows a gouge I bought, the homemade 1/8-inch chisel, and the blank for a slightly larger 3/16-inch chisel.  I'd planned to make a gouge, but after hammering on the red-hot wire for a while, I decided I'd need to start with a larger blank for a gouge.

Garet

[Oceaneer99]

I finally finished the 3/16-inch chisel:


http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-2334

These two homemade chisels work really well, and are sharp enough to shave with. The chisel in the front is 1/8-inch, and the one in the back is 3/16-inch. They are both made from 5/32-inch hardened music wire. I annealed them, then cut and filed the bevels. I hammered the end of the wire for the wider chisel after heating it to glowing orange to make a wider blank.

They were both heat-treated using a propane torch, dunked into oil to quench, and then tempered to 400 F in a kitchen oven.

The handles are cut from a length of 3/4-inch square poplar. I drilled a slightly undersize hole through the handle blank (had to drill from both ends), then cut them to an octagon with a chisel and plane. I drove the chisels in by placing the sharp end on a block of scrap and driving the handle on with a mallet.

Many thanks to Ray for the inspiration to make these!

And here is a way to protect those sharp edges (and your fingers):


Those new-fangled synthetic wine corks make great blade covers for chisels and gouges. Colorful, too!


Garet

[Oceaneer99]

This weekend, I finally made handles for my other homemade chisel and 5/32" gouge.

[lastvautour]

What was the hurry? Glad to see you posting from time to time.

Lou

[Oceaneer99]

I had to use the smallest chisel for a project, without a handle, so I thought, "Gee, I should make those handles".  The hardest part is drilling the hole in the handle, which I need to do from both ends.  This time, I built a small jig for the drill press to help keep the holes straight.

Garet

[Balsabasher]

Nothing quite like making your own tools like this,and as you have found out the hardness is the secret.
Keep your eyes open for stainless steel tube,if you can get it then it makes excellent gouges once ground and sharpened,you can cut the top off to make them just like conventional chisel gouges.
Barry.

[lastvautour]

Garet, the ones you gave me came handy on a number of projects.

Lou