How to use Norwegian Ragstone? Dry/Oil/Water ?

[Sv1]

Hey so i get myself a Norwegian Ragstone and i was wondering if anyone here know what the best way to use it Oil/Water/ or just use it dry

I did manage to get paper slicing edge by using it just dry but i was wondering if its better with oil or water ?

 

[Obsessed with Edges]

Being a natural stone, I'd not use it dry; it'll likely clog pretty fast that way. Use water at least, to keep the swarf from loading up the stone. With the apparent 1000+ years of sharpening history behind these stones, I'm guessing they weren't originally used with oil anyway, but perhaps with water at the most. I don't think oiling the stone would do any harm though, as per it's use on natural Arkansas stones these days.

Depending on the steel(?) being sharpened, glazing (wear) of the stone's natural grit might be a concern too. If the steel is very wear-resistant, the stone may not be very effective in sharpening it, and the stone itself may be damaged by glazing, i.e., the natural abrasive's cutting edges being smoothed/rounded off, in the process, rendering it ineffective on anything else as well. From what I'm reading about these stones, they're composed of a natural fine-grained schist, which isn't very hard (Mohs 3-5, depending on what reference you look at). The lack of adequate hardness in these might be problem with most modern knife steels (Mohs 5-6+ usually).


David

 

[HeavyHanded]

I'd start by using it with water. If water soaks in and any mud forms on the surface then I'd keep using it with water.

If no mud forms and the water doesn't appear to soak into the stone much if at all, I'd try with oil, but only on one side in a small area.

Apparently it can create several finishes depending on which direction you run the edge relative to the stone layers.


Here's some more, starts on page 71. Sounds like a nice find:

https://bosq.home.xs4all.nl/info 20m/grinding_and_honing_part_3.pdf

 

[Sv1]

Thanks ! i cant find anywhere what grit the stone is
can you maybe tell from a picture or take a good guess ?
http://imgur.com/a/iEz82

it feel really smooth if i can compare it to anything i have a fallkniven CC4 i would say its much smoother than the grey side but not more than the white side

also the stone do remove very little amount of steel compared to the fallkniven CC4 (both sides) i do not see wear marks on the stone however

Thanks

 

[Obsessed with Edges]

It's a natural stone, so estimating the actual 'grit' would be purely speculative and likely inaccurate. Being 'natural', I'm sure the actual crystals of it are highly variable in size and/or shape.

It's not surprising that it doesn't seem to remove metal aggressively, as the relatively soft makeup of the stone would limit it's aggressiveness, probably to a large degree. Even large 'grit' can behave like much finer grit, if it's not very hard and/or doesn't have very sharp cutting edges on the mineral crystals.

The best way to get fully acquainted with the stone is to use it. Over time, it'll become much more apparent as to what finish it'll leave on different steels. I'd assume it may not work well at all on more highly-alloyed modern steels, as they're much more wear-resistant and probably too hard to abrade effectively. On simpler steels though, like 1095 and maybe some low-alloy stainless like 420HC, you might find it works OK as a finishing or light maintenance stone.


David

Thanks ! i cant find anywhere what grit the stone is
can you maybe tell from a picture or take a good guess ?
http://imgur.com/a/iEz82

it feel really smooth if i can compare it to anything i have a fallkniven CC4 i would say its much smoother than the grey side but not more than the white side

also the stone do remove very little amount of steel compared to the fallkniven CC4 (both sides) i do not see wear marks on the stone however

Thanks

 

[HeavyHanded]

Thanks ! i cant find anywhere what grit the stone is
can you maybe tell from a picture or take a good guess ?
http://imgur.com/a/iEz82

it feel really smooth if i can compare it to anything i have a fallkniven CC4 i would say its much smoother than the grey side but not more than the white side

also the stone do remove very little amount of steel compared to the fallkniven CC4 (both sides) i do not see wear marks on the stone however

Thanks

I'd think about lapping it with sand or silicon carbide grit and a flat piece of granite or glass etc with plenty of water. The stone itself might be glazed up. I'd also do any evaluation with plain carbon steel and then try it on tougher stainless.