Will a grinder cut it for sharpening?
mikkimel
| Posted in Power Tools and Machinery on
In the past, I’ve done all my chisel and plane iron sharpening on water stones. Lately i’ve been thinking of getting an 8 inch slow speed bench grinder to put a hollow grind on it before going to the water stones for fine tuning.
I can get one of these bench grinders for $100 or less, they all say they are slow enough (1700 rpms) so they won’t destroy the tool. I’m assuming that if i sharpen in short bursts, and let the tool cool, it won’t lose it’s temper. I really don’t have the money to get a tormek, but if the grinder isn’t worth it, or i’m going to destroy my tools i’ll just stick with just the water stones.
your thoughts?
Replies
Mikkimel , I have never been too concerned about the speed but more concerned about the type of stone. It is my experience that the darker the color of the stone the harder it is and the less heat gets absorbed by the stone :hence the tool steel heats up which as we know is not good. I use what are called sugar stones or white grinding wheels.They are very soft and absorb more of the heat while keeping the tool cooler. The only negative thing is the cost of the white wheels is considerably more and they dissipate faster . I then use an oil or water stone to hand hone to a razor finish .
good luck
mikkimel
In lieu of a grinder, I use a 200 grit green stone. Unless you've got some big chips-outs, it's about as quick with less chance of over-heating. If you sharpen a lot of yard equipment, axes, etc., etc. the grinder would probably be the better choice over-all.
Regards...
sarge.jt
Sarge, how do you establish the initial bevel angle using just the stone. Do you do it freehand or with a honing jig?
Mark
On the 200 grit water-stone, I use the Veritas angle setter and a jig. That is the only situation I use a jig for sharpening. I want to set the initial bevel as close to exact as possible. Now that does not mean being fanatical about perfect. Once that initial bevel is set, honing and micro-bevels when I use them are all free-hand.
I never use a grinder except if there is a major chip-out on a tool. If you have good steel, about the only way that happens would be to accidentally drop it on concrete. Or just flat abusing what the tool was designed to do. I have mats on the shop floor so chips from dropping is almost ruled out in my case.
I felt un-comfortable without the jig at first, but a little practice and pure concentration builds confidence. Soon, it just felt natural and the results were there. But the jig does help me establish the initial angle to work free-hand from. You should only have to establish that angle when you get a major chip or when you have honed the intial angle down from re-sharpening so that that angle is lost.
I strop often and with good steel, even honing will not bring that angle down for awhile with quality steel and the proper steps taken from the time the tool was originally prepped.
Regards...
sarge..jt
this might help. http://www.planemaker.com/articles/grinding2.html It takes a little practice, but once you put a nice hollow ground on a chisel or plane iron (make sore the backs are absolutely flat and polished) sharpening the to a razor finish takes minutes. And tuning them up takes seconds.
Try using sandpaper on glass. I have talked to several woodworkers and they swear by this. FWW had an article on this also a month or two ago. I tried it and just using my hand I can get a razer edge. Try this before you invest in a grinder.
Ken K
Mikkimel,
Stick with your stones. Why put good tools at risk? Or as the fellow who taught me once said: "very few good things can happen if you use a grinder, but many bad things will happen, sooner or later."
Alan
Go to sears and pickup the very slow speed grinder that you can use wet (small trough) Works great and has a wide stone with little danger of over heating the cutting edge. Finish with a "touch up" on diamond stone or the like.
Well, I will actually answer your question...I have the Woodcraft grinder from Taiwan (blue) with the white wheels that are AlOx, and it has never burned any of my irons or chisels. The tool rest does stink, so upgrading would be worthwhile with a store bought or shop made rest. Keeping the stone clean and grinding in short bursts will not generate enough heat to hurt your iron. I remove so little metal during maintenance grinding that I don't normally quench my irons. The feathered edge of the iron is what really runs the risk of bluing, so when you get close, pay special attention.
Tom
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