DISC GRINDERS = hollow grind?

[simko]

Is it possible, does anyone grind knives using the disk grinders? ive got an old one thats 6".... can i use it to hollow grind blades?

 

[Mike Hull]

If you use the edge.

 

[etp777]

Are you talking about a disk grinder(flat disk with a round piece of sand paper attached to flat part of disk) or a bench grinder(5", 6" or 8" stone of approximately .5-1" thick that you grind on the edge of) such as you buy at any hardware store, often with two shafts, one stone on each, or one stone and wire wheel? If the second, yes you can hollow grind, and someone in here does(or more than one) just don't remember who. With the first, you can in theory, but I've never tried it.

 

[simko]

the machine with dual shafts, and stones.....

 

[allan lanigan]

Aaron,I know of a fellow that make very nice knives with the stone wheels and some fine grit stones are available.That being said i think the belts offer too many advantages over the stones......

 

[simko]

ah ok

 

[etp777]

argh, wrong thread.

 

[KennyC]

yea, it'll work. i use mine to make mild steel throwers, but be forwarned, they heat up the steel VERY quickly. its fine with mild steel as theres no temper to burn out, but other steels will have to be cooled often. good luck and post some pics.

Kenny

 

[Protactical]

You can grind knives on stones, and the endge will be hollow, in most case. That's how it was traditionaly done. You can see these great pictures of guys in SHeffied lying on their stomachs grinding away on pretty big wheels, driven by line shafts.

The downside is that the stones need to be very true, and kept clean (therefore you need to buy a tool for that), when used agresively they wear quite quickly. And they can fly apart and maim you. Belt sanders start at about 60 bucks, and have none of these problem...

The thing I like about grinding stones is that at standard operating speeds (no expensive variable speed units considered) they don't remove much steel, which means that tools like expensive HSS wood turning chisels last much longer than if sharpened on a fast belt unit. At 1800 rpm, you can use the stone you are cutting on almost as a jig, to roll a perfect cutting edge for the task. Burning isn't a problem with HSS, or one can buy the cool runing stones for the grinder, that wear real quick, but don't get hot. All this is kinda contrary to what one wants in a knife grinder.