Thread: Sharpening with grinder, new questions

Originally Posted by Ben from Vic.

Is the step from the Bluemax wheel (56 grit) I intend to get from CWS to the green crayon to big?

Not if you consider the distance from Sydney to Melbourne just a short walk

Hey Termite, how'd you manage to get such a big avitar?? :eek:

Oh no. Another sharpening thread. :eek:

Run away! Run away!

Originally Posted by Ben from Vic.

Hey Termite, how'd you manage to get such a big avitar?? :eek:

Plenty of use.

I know, I know, I tried not to, really.

I did search first, and it was helpfull in building an overall picture, thats why my questions are fairly specific.


Termite, I knew that question was going to get me in trouble, I just couldn't think of a better way to word it.


Ben.

Ben

A few rules for grinding blades:

(1) The smaller the diameter of the wheel the better! Don't go thinking "bigger is better" (OK, down guys!). What you want is a deep, but small hollow grind. A big wheel will not do this. So get a 6" wheel instead.

(2) The good news is that these 6" machines are cheaper. I hear good things about A & A, but a grinder is such a basic machine that you really can get a cheapie - the provisor is that the wheel turns smoothly and concentrically.

(3) The important parts of the set up are (a) the wheel type, (b) grit level, and (c) the blade support system.

(a) and (b) The rule for the wheel is that you want the coarsest possible grit, say 60. Why? Because these machines turn far too fast and a smooth wheel will generate too much heat and burn the blade. You could probably keep the grey wheel if it is a very coarse example. I have a white one. Others swear by the pink.

(c) a decent support is made by Veritas. A cheaper - very acceptable - version of this is sold by Carba-tec under their house brand.

(4) Keep in mind that the point of hollow grinding is to reduce the amount of metal to sharpen. It is NOT a sharpening method on its own. You do not want to grind to the blade's edge. This will not only just weaken the edge, but it will very likely burn it too. My plan is to flat grind/sharpen the blade to the bevel angle I want, then hollow grind inside the bevel, leaving about a 2-3mm edge.

(5) Don't hollow grind laminated blades (such as Japanese blades).

Regards from Perth

Derek

6" is better than 8" for grinding purposes? A smaller wheel produces a deeper hollow therefore removing more material in turn producing a weaker edge, no?

P.S. I prefer to have 8".

Krenov recommends a 5" or 6" diameter wheel. He argues that "the larger wheels produce very little hollow grinding" (from The Fine Art of Cabinetmaking).

Regards from Perth

Derek