Finishing grit for thinning?

[Jovidah]

Maybe a bit of a silly question, but what grit is considered 'optimal' to finish your thinning on a normal gyuto? I know a lower grit creates friction and hampers while cutting...but a mirror polish tends to be stickier. Is there some kind of sweet spot?

In my own arsenal I have 400, 1000, 3000 and 5000/6000 grit to choose from... Which one to finish with?

 

[masibu]

generally i dont go higher than 1000, mostly due to the fact removing all scratches is time consuming and i happen to rush through the grits sometimes thinking ive finished as im impatient. I've just happened to have purchased some coarser super stones off ebay to try my luck with this same task

 

[preizzo]

My 400 chosera leave a perfect finish.!! I use to polish later with a series of rounded shape pattern up to 4 k. Just quick touch to give the blade be more power of penetration 😉

 

[mark76]

It's hard to generalize, but from the maker quite a few blades are finished at 600-800 grit, I think. 1000 is pretty fine already. If it's for the looks, make sure all scratches go in the same direction.

 

[XooMG]

I do not like anything under about 2k-ish as a "working finish" on a knife, depending on the polishing medium.

For natural stones, I think my binsui/aizu/igarashi are OK, but a little coarse with base stone slurry, and a finer nagura on the stone gets it in the right neighborhood for a low-grit working finish.

For synthetic stones...the red synthetic aoto (2-4k mix) from Maksim is OK, and I will use it to "tame" an 800-grit finish, which is way too coarse for me (the fogging masks it but the drag is there).

For diamond pastes on paper or balsa or whatever (not very often) I think 2-5k is generally fine.

For sandpaper, 1200-2000 grit is generally satisfactory, chased with some autosol.

For 3m polishing sponges, Superfine (400 grit) is a good start and microfine (1500ish?) is usually plenty, but these cut very differently from other media.

It's hard to make any absolute statements since I mix media pretty often.

I do not think highly polished surfaces cause significant sticking, though they might exacerbate a problem if the bevel is too flat and thin.

 

[Jovidah]

Funny enough I actually didn't really consider it all that much work to polish it up; just a few minutes on the 5000 stone.
But I guess if it's not conclusive I'll just mess around a bit and see if I can find a difference.

To some extent I do prefer to leave it somewhat 'rougher' as the edge bevel; makes it easier to spot the difference. Pretty difficult when it's all one big mirror. But I was wondering whether there was a golden rule about when drag starts to become problematic.

 

[panda]

I leave mine at 600. Quite a few people use king 800 specifically for blade finish.

 

[Jovidah]

Figured I'd give this a bump again. Haven't really done much experimenting in this department in the last few years, but the same question came up for me... what's the current opinion for the best grit finish to strike a happy medium between avoiding drag and avoiding vacuum mirrors?

 

[stevenStefano]

I go to 5k. I haven't noticed any food separation issues, and it also looks cool

 

[GorillaGrunt]

Somewhere 2-5k, I feel like I can feel drag from lower. But i don’t need to polish the crap out of it, just a little bit on the last stone smooths it out if I’m not going for looks