Do I need 400 grit SiC powder?

P

Papilio

Joined
Sep 6, 2019
Messages
356
I know we just had this topic here: https://www.bladeforums.com/threads...ing-dressing-lapping-guidance-needed.1903520/

I have an additional question and did not want to hijack the thread.

iI think about buying silicone carbide powder for flattening and resurfacing. Availabe in 60 grit, 120, 180 and 400.
As I said it is not just flattening but also resurfacing fine grit stones. 1.000 JIS and 3.000 - 4.000 and maybe finer. Which one of those for grits should I buy? 60 for flattening seems to be clear.
 
Funny thing about SiC powder, it's like the weather in some parts: if you don't like the grit, wait a minute. It breaks down into something finer quite fast.

I do flattening of Arkansas stones and Washitas with 60 or 80 grit. I like putting the SiC on sandpaper; it seems to work well. Even once flat, I don't seem to need anything finer for those than 60 or 80, or what it breaks down to in a few minutes.

I keep 400 grit around, but only to surface razor finishing stones, black and translucent arks.

What sort of stone are you dealing with? Friable-bond stones are not dependent on surface finish the way Arks and Washitas are. The only times I've used SiC on waterstones were for flattening very coarse stones, under 300 grit, and for that, it's the same 60 or 80 grit that works well for that. If you are flattening or deglazing a stone in the grit range you mention, a diamond plate may be a better choice.
 
Honestly I don't want to spend a fortune for good diamond stones actually. And I don't want to buy cheap ones, too. They wear out so quickly.
That's why I asked about SiC powder.
I don't want to flatten friable-bond waterstones. I'm talking about coarse oilstones and fine sintered ceramics. Like these https://www.fine-tools.com/kuns.html
Flattening coarse oilstones with 60 grit SiC should be sufficient. But I am not sure what I need to resurface (not to flatten) the fine stones (1.000 and 3.000 JIS). When they start to glaze.
 
Last edited:
Yup, with sintered ceramics, you are on the right track with SiC powder. I don't have enough experience with that kind of stone to say what grit would be suitable for surface conditioning for sharpening knives. In your position, I would get some of each (though probably only one of 120 and 180). Or really, I'd get a larger quantity of 60, and moderate amounts of 120 and 400, and start experimenting to see what I liked. SiC powder is very cheap here in the US.
 
Ok, great. I will do as you suggested. 60, 120 (or 180) and 400.
Do I understand you right that there isn't a big difference between 120 and 180?
Thanks.
 
Papilio said:
Ok, great. I will do as you suggested. 60, 120 (or 180) and 400.
Do I understand you right that there isn't a big difference between 120 and 180?
Thanks.
Click to expand...
It's an assumption I made early, not one I've tested. Given how readily SiC breaks down, I just could not imagine that the difference would wind up being significant. Of course I could be wrong about that.
 
Papilio said:
Ok, great. I will do as you suggested. 60, 120 (or 180) and 400.
Do I understand you right that there isn't a big difference between 120 and 180?
Thanks.
Click to expand...
The difference between those two grits are small. I would go with 120 though.

With those 3 grits you will be good to go and able to flatten any dished old oil stones.
 
You must log in or register to reply here.
Back
Top