SP-650 grader or dual sided whetstone - identification

[ClimberSam]

I recently picked up a Supergrind 1200 with a set of accessories, including this stone.  I'm not convinced that it's an SP-650, the current version looks much darker, but this one would be quite old (similar to the 1200).

Couple of questions:
- Do you think it is an SP650?
- If it's not, am I going to damage the grindstone on the Tormek if I try and use it for grading?  I appreciate that it would be at my own risk, but if it's not going to break anything then I'd give it a go before ordering a genuine version.

All comments/thoughts appreciated.

[Ken S]

Welcome to the forum, Sam. The colors don't look quite "standard issue Tormek"; however, it might work OK. I don't think it would do any damage. I would try it.

Ken

[RichColvin]

I can't tell from the picture, but is one side pretty rough, almost like lava stone?  I ask as the rough side of the SP 650 is used to grade the grindstone towards the 220 end, and the smoother side gets used to grade that grindstone towards the 1000 end.

[ClimberSam]

Thank you for the replies. In reponse to 'I can't tell from the picture, but is one side pretty rough, almost like lava stone? '
The surface of the coarse side is pretty smooth, but the structure underneath is quite grainy, probably not quite as coarse as pumice stone, but not far off.
I'll give it a cautious go on the wheel and see how I get on.

[tgbto]

I find it awkward that the stone is scratched that bad. Granted, rounding out the edges without moving the stone can be hard on the grader, but still,  I think I'd have to stay for a *looooong* time at the exact same place to make a scratch that deep, let alone several.

Even my mennaoshi kuns for much softer japanese stones wouldn't wear that fast.

I'd wager this stone is not intended for this use, and I doubt it will efficiently grade the SG if the scratches were made with the SG in the first place. Maybe a misused grader for the earlier natural Tormek stones ? Someone at Tormek support might be able to help.

[ClimberSam]

Well, I gave the stone a go on my Supergrind.  It didn't do any damage, and the coarse side seemed to work quite effectively.  However the fine side of the whetstone wore down very quickly when I dried to smooth the wheel up again.  Worth the experiement, but I've now ordered an SP-650 for future use.
Thanks for all comments, much appreciated.