Blade Regrind with Tormek T7?

[_centurio_]

I have to try your way of doing it. I layed the knife flat on the primary grind

How compares the Sigma Select 240 grit to the Shapton 220 grit in terms of wear and speed?

BR Oliver

[Cliff Stamp]

I have not compared them yet, I am still working with the Naniwa Superstone 400.

[_centurio_]

OK I'm looking forward to the results. Currently I am searching for a new coarse stone and I can't decide between the Shapton 120, Sigma Select 240/400 and Naniwa Super 220/400. I need a stone which abrades a lot of Steel (all kind of) and leaves a stable finish with which I can put a microbevel afterwards.

[Cliff Stamp]

I don't think you would like the Shapton 120 :

http://www.youtube.com/watch?v=3ABYFdjAw9s

It cuts well, but is fairly soft for a coarse stone and even under low pressure a lot of abrasive comes off fast. I think you would only be happy with it using it on something like the back of a chisel where the contact area is so wide. I am not sure about abrading a lot of steel and being able to jump to a micro-bevel directly. That is kind of asking for two complete opposite things.

[_centurio_]

Yes you could be right Maybe the Imanishi Bester 220 and 400 would be a good combination. Hehe a lot of stones to choose from

[Cliff Stamp]

Mark is using the Shapton 120 I had :



and finding much the same that it is fairly soft and gets muddy very fast : http://www.cliffstamp.com/knives/forum/ ... #msg-34617" target="_blank

This stone seems to be designed to work on very large areas only as if the pressure gets high it gets very friable, hence it isn't in generally recommended for knives. The Sigma Power however is almost the exact opposite, people complain it is too hard.

[Donut]

Do you have a before picture? It really should not take that long. How much force were you using (approximately) and how many passes were you doing (approximately) per second (or minute).

I think this is what it looked like before. :)

[_centurio_]

Yes, the Shapton 220 grit also gets muddy very fast.

The Sigma Select Series is meant to grind HSS and other very high amount carbide steels as far as I know, so these stones should not be too hard, but I have no experience with the Sigmas.