Serious grinding

[Up_dog128]

Hey y'all. I'm new to this forum, so if there is a thread that discusses this already, please point me in that direction.
I've got a bit of thinning to be done on some gyutos, and serious bevel changes on some belt knives, and I'm curious what your experiences have been with using very coarse grit whetstones (specifically Shapton Pro 120 grit) vs. diamond plates. My only Whetstones are Imanishi/Bester 1200 & 4000, and I have no experience with coarse ones. I'm thinking of getting the shapton 120, but I'm concerned that it'll dish and wear out too quickly to be an economical choice, and also wondering about cutting speed compared to diamond.

 

[vicv]

I'd get a coarse Norton crystolon stone. Is very fast and hard

 

[Yet-Another-Dave]

I'm not sure what you consider "a lot", but for large values you want want to consider the Harbor Freight 1" x 30" belt sander and some metal grinding belts to match. Not a high end setup, but seriously fast for pretty cheap. (Just remember if you can grind fast, you can screw things up at least that fast.)

 

[M1k3]

I've used both coarse Crystolon and Shapton Pro 120. I think the Crystolon cuts faster, but, needs refreshing. Whereas the Shapton Pro doesn't necessarily need refreshing, but, can sometimes use it. It doesn't really need it for soft stainless cladding. That seems to generate enough mud to not load/slow down.

 

[adam92]

I've used both coarse Crystolon and Shapton Pro 120. I think the Crystolon cuts faster, but, needs refreshing. Whereas the Shapton Pro doesn't necessarily need refreshing, but, can sometimes use it. It doesn't really need it for soft stainless cladding. That seems to generate enough mud to not load/slow down.

SP 120 not good for Stainless ?

How about AS in Stainless cladding & SG2 steel?

My SP320 almost end of life, thinking of replace.

 

[M1k3]

I'm saying it works better on soft stainless cladding, in my experience.

 

[Up_dog128]

Well, the Shapton is on sale for $26, which is about the same as the Norton crystolon 8". Given that, which would you choose? Also, which would have deeper scratch pattern that I'ma need to get out?

 

[M1k3]

Freshly lapped Crystolon will leave deeper scratches than the Shapton. That said, I have no issues going Pro 120-> Glass 500.

 

[dough]

I gotta say your idea of “a lot” is most likely not mine Bc I really think power tools like belt sander or I guess Dremel are more what I think of when a lot of metal needs to be changed.

 

[M1k3]

I gotta say your idea of “a lot” is most likely not mine Bc I really think power tools like belt sander or I guess Dremel are more what I think of when a lot of metal needs to be changed.

Not everyone has the space for that. So hand tools are the way to go. Otherwise I definitely agree.

 

[inferno]

diamond plates are very fast but you also wear them out fast.
and they create very deep scratches, so you will still need a coarse stone.

i have tried 100grit sic, 220 glass/pro, 500 glass. they all work. The best is probably getting a cheap plate and several coarse stones 220 or lower. and coarse paper. you will probably end up using all of it.

 

[jacko9]

I just used my Nubatama 180 Black today and it works fast, stays flat and gets muddy quickly. I step up to the SP 320, SG 500, 1K (I have 4 of them so I rotate).

 

[Benuser]

You may consider automotive sandpaper as well. Works well with a hard rubber or soft wooden backing. Edge trailing only to avoid overgrinding. Start at P120. In Europe, the best I know is 'Metall' by Robert Bosch.

 

[Caleb Cox]

I'd suggest sandpaper as well, with softer backing where you want some convexity, otherwise use ridged backing like granite, glass, or even MDF is generally quite flat.

 

[vicv]

Even good sandpaper just wears out too fast. That is a problem with getting it stuck down properly. Or getting a really expensive contraption a hold it. serious you can get a cheap silicon carbide stone for like two bucks. And it will last many many many flattening jobs

 

[ojisan]

You might want to buy some SiC powder as well to flatten Shapton Pro 120.