How To Use A Bench Grinder
VideoJug shows you how to use a bench grinder properly and sharpen your tools when you do need them for a DIY project.
This is a bench grinder and it's used for sharpening chisels, knives, things like that. You use the front edge, you don't use the sides, you just use the front edge, it comes towards you, spins around, and you rest your tool on the rest, and this little guard is to protect your eyes from the sparks of metal that fly off, and you move it all across when it's spinning obviously, left and right, to get rid of any nicks you may have in there, you may have been chiselling and hit a screw. This one's also got a water sharpener at this end, too.
The stone sits in a bath of water and it brings the water up and cools the chisels as you sharpen them, and it's got these little parts here to rest knives on, axe blades and things like that. It's not that safe to sharpen a knife on here because what often happens is it gets pulled down like that, and you don't want a knife moving very fast in front of you. So, I'll show you first of all, this end.
What you've got to try and do is look at the blade and you'll see a scooping at the back. There's a flat front and you'll see a couple of nicks where I've hit things, they're not very big nicks but I'm just showing this to show you the machine. What you need to do is increase the size of the scoop, the scoop part is here, but you leave the front edge.
If you get the blade too hot it goes blue, and when it goes blue, it loses its temper - that's how hard the blade is, so what you want to do is every now and then, you stop and dunk the blade in water, that just cools it down. Then, you just dry it and then just keep on grinding a little bit. So, for this, you need goggles and ear fenders when you look from the side, to try and judge where you are going to touch it so you don't actually touch the front edge on, and carefully move it from side to side and you'll see the whole clean area there where I've ground off.
It's quite aggressive, this thing, if you cut too close to the front edge, you will make the steel go blue, so always just scoop the back out. This one here is cooler because it's got the water cooling on, the stones all wet, it's much slower. It's basically the same principle on this one - the stone goes towards you, on this one the stone goes away from you.
On this one, you can sharpen up to the edge. Again, you judge from the side so that you get the whole blade being sharpened and just move slowly across. If you keep the blade in one place all the time, you just wear a big groove in the stone and you can't sharpen anything flat so you keep moving across to keep the stone flat not just to keep the blade flat.
You don't need to stop and dunk it because the blade's actually quite cool. You can see it's fairly easily sharpened all the way across. That's not actually sharp enough to use yet, you then want to use your sharpening stone, sharpen it on that, and then lap it.
But it's good to get big nicks out with and good to sharpen a tool before honing it. .