Thread: Making your own chisels

I would be careful about using a conductive coolant with a 100mm angle grinder. It would be like using your grinder standing out in the rain. Radiator coolant is not the product you should be using as there would be little benefit in it's slightly higher boiling point compared to water. Coolant for metalworking is a soluble oil that provides lubrication that reduces heat from friction as well as having a cooling effect. Grinding disks are manufactured for wet or dry use and I haven't seen a wet disk for a 100mm grinder yet - not saying they are not available though. Another problem is that unless you can slide the shaft along it's axis the cut will be a series of dish shaped gouges. The profile will be a straight sided flat bottomed grove rather than countoured to the shape of the outside.
Sorry that I have bagged your idea but the only solution I can see is a milling machine using a rounded carbide cutter.
I knew a turner that made all his chisels by gringing the teeth off and shaping old metalworking files. That was until he hung a bit too much file over the rest and had one snag and then snap. He was working with a fairly large blank and had a long handle attached. Fortunately he wasn't hurt but there was a lesson to be learnt - somthing along the lines of use the right tool for the right job.

Smidsy

Some views and previous experience.

In my learning (and impoverished) days, I did a bit of this, as I could not afford bought tools. In addition, back where I came from, the price of (imported) tools was exorbitant. (about 5 times P&N, as a %age of average earnings.), so a few people in the woodturning fraternity had explored this to an extent.

Firstly, while not HSS, a fairly good grade of high carbon steel is used in spring manufacture. I made acceptable scrapers by cutting out of sections of leaf spring. Use an angle grinder, and work slowly to avoid losing temper.(of the steel too!).
Spring steel bar, (I bought a scrap front suspension anti-roll bar, and have used the spring steel bow leg from a camp stretcher) can be used to make bowl gouges. I gripped the bar in a vise, and ground a small flat (3mm wide) along the proposed flute length. Then, using 100mm gringer, with a metal cutting disc, and grinding carefully, hand held, with the disc on edge, slowly and carefully carve the flute in, using the pre-ground flet as a starting point. Slowly is the watchword. Cool frequently. Watch the depth and evenness of the groove, as it is easy to gouge too deep. By angling the disc to left and right, it is possible to adjust the profile of the flute, but the minimum radius is pretty well set by the thickness of the disc. I still occasionally use one of these tools for small and light work. Others have been replaced by P&N, but have been passed on to a friend who is starting up, and are still in use.

For the more advanced, HSS will retain its hardness up to silver soldering temperatures. In a prevoius life, one of the club members would buy short sections of exotic HSS bar, and pay to have the required profile cut using a CNC plasma cutter (I think!). This would then be silver soldered to a carbon steel bar for length and strength. I have lost contact with the club, but could try and locate, if someone was interested.
Similarly, a 1/8" layer of HSS can be silver soldered on top of mild steel flatbar, and ground to yield excellent scrapers, especially for those exotic curved and hooked scrapers, which break my heart to make by grinding away all the expensive HSS I have just paid through the nose for.

Hollowing tool tips, (a la Soren Berger) can be home ground out of HSS bar. My sizing tool (8mm square rod) parting tool (1" X 1/8") and heavy section square skew chisel (1/2"x1/2" bar) have all been ground up from HSS blanks.The "swan neck" shaft for my hollow form tool was home forged from 5/8" mild steel roundbar, and there are other projects in the pipeline, mostly fuelled from stinginess

Just to finish up, all my first 5 years of turning was done using a set of carbon steel gouges which had been hand forged from mine drill steel by my blacksmith grandfather, in the '30s. The roughing gouge was only replaced with a bought one 2 years ago, and I used the parting tool on a tricky job just weeks ago.

Finally, like most of us, I have used files as scrapers. I have been lucky, but using a brittle hardened steel, which has been specifically pre-made with a couple of hundred incipient cracks on the surface, is best described as a high risk venture!

Regards,

Woodturning magazine had an article on Ashley Isles method of manufacture a couple of months ago. Basically a thin grinding wheel was shaped to the required inner profile and that was then used to grind the inner groove and was done dry!!! Aparently it is a bit of a myth this make HSS blue and you have removed the tempering, you really need to go above 1000 degrees to do that. I do not see that the method would not work and have thought of doing the same for myself. I would definitively stay away from any file, way to easy to snap and HSS blanks are not that expensive from places like Gary Pye.

Hei Guys,
Thanks for the input.
The reason I used coolant instead of water is that I'm thinking of the corrosion issues of water and I used coolant because it has corrosion inhibitors in it.
Of course you need to be careful with any liquid around power tools but with care it is safe.

I've only made two chisels so far, but I only use tool steel blanks, all the files I have are good english and australian ones from my father which I wouldn't sacrifice on a chisel - besides, the tool steel blanks are fairly cheap.

The idea of shaping a brinding wheel to the profile sounds like a good idea as I have about half a dozen bench grinder wheels floating round my shed.
It is all food for thought.
Cheers
Paul

I have recently finished a metal machining course at tafe and had a substantial number of HSS tool blanks left over. They are about 2 inches long and 1/4 inch square. To make long boring bars I drilled a hole large enough diagonally through the end of a piece of round bar to take the HSS. A grub screw in the side and mount the other end with a handle. I know the my description is rough but dad has my digital camera in sydney so i can't take any photos at the moment. I will post some photos when i get the camera back.

I've bought a few HSS blanks from Garry Pye or McJing over the web and shaped them for scraping. Takes a while though on a white wheel.

Scraper can easily be made from the appropriate sized mild steel bar and have your local welding fabrication shop simply weld on the end 8-10mm or chromium hard facing. When you have finished grinding this off in about 3years take it back and start again. Bloody simple.

Carbatec sell the tool steel blanks for between $8 and $25, so for a scraper it's not worth the hassle of welding.
I've made two scrapers so far, a standard 10mm curved end scraper and a 25mm scraper with a straight end but with the cutting edge extending about 50mm up the left hand side of the blade.

All I did for sharpening was use an existing scraper to get the angle and it took less than 5 minutes to do each one.
Cheers
Paul

Originally Posted by rsser

I've bought a few HSS blanks from Garry Pye or McJing over the web and shaped them for scraping. Takes a while though on a white wheel.

Ern, if you use a metal cutting wheel in an angle grinder to rough shape it is a lot quicker.

Originally Posted by

Ern, if you use a metal cutting wheel in an angle grinder to rough shape it is a lot quicker.

Nifty. Cheaper too I'd guess.

And you control the heating effect in the same way by dipping into water?

Never, Ever Not no How dip HSS tools in water. It can fracture them.

If they get hot let them cool on their own.

,
So that is a definite no then?
Not disputing what you are saying but that is the first time I have heard not to quench HSS in water. I sharpen a few HSS lathe and milling flycutter bits (1/2 inch square toolsteel) and the method of shaping and sharpening is to quench often.
Ahhh the penny might have just dropped. By quenching often I do not let the HSS overheat (blue) so the temperature variation is unlikely to cause internal fractures.

Originally Posted by rodm

,
So that is a definite no then?
Not disputing what you are saying but that is the first time I have heard not to quench HSS in water. I sharpen a few HSS lathe and milling flycutter bits (1/2 inch square toolsteel) and the method of shaping and sharpening is to quench often.
Ahhh the penny might have just dropped. By quenching often I do not let the HSS overheat (blue) so the temperature variation is unlikely to cause internal fractures.

That is the key if you do quench. Most turners because of where the tool is held while sharpening (away from tip) they quench it when it gets too hot. Better not to quench.

Thanks
Small bits of toolsteel do get a bit heavy to hold after short busts on the grinder.