Rust stains on stones?

[MattPike4President]

Been messing around with my roommate's janky tojiro deba recently and spent some time last night going to town with a pink brick. Found the stone this morning stained brown in part of the area where I work.

My assumption is that this is residue from the soft iron cladding rusting overnight as the stone soaked and that it doesn't really pose any issue, but I couldn't find any information on this in my initial google searches so I figured I'd ask here

 

[Pie]

Pretty sure it would be just swarf and rusty mud. A good flattening should clean it up.

Although is it permasoaked? I don’t have any experience with soakers but I can’t imagine it’d be anything other than load up and metal.

 

[kitchensamurai1]

I would consider scrubbing it with a flattening stone and then wiping it down with a sponge and some detergent. Agree that it's probably some oxidized metal particles.

 

[MattPike4President]

Flattening got rid of the vast majority, will try detergent next time if it continues to be an issue. The stone is permasoaked, but the water is changed regularly and the other stones it lives with are completely fine so I'm pretty sure it's not mold

 

[Pie]

Flattening got rid of the vast majority, will try detergent next time if it continues to be an issue. The stone is permasoaked, but the water is changed regularly and the other stones it lives with are completely fine so I'm pretty sure it's not mold

I almost like the stains. It makes it easier to see if it’s completely flattened.

 

[Wagnum]

Happened to my pink brick too. It's so porous that the the rust penetrated deeper than just a quick flattening. I imagine I could chase it through more of the stone than I'm willing to loose

 

[Choppin]

flattening after you are done using it and before storing helps. also, adding a bit of sodium bicarbonate to the permasoaking water prevents rust and other weird stuff.

some manufacturers don’t recommend cleaning stones with soap or detergent (Shapton Glass’s leaflet says that). something to do with the binders I assume? not sure about soakers though

 

[Heckel7302]

I almost like the stains. It makes it easier to see if it’s completely flattened.

I rarely flatten all the way for sharpening. I just flatten enough to have usable area, then it's easy to see where the low spots are on the stone and I avoid them while sharpening. Good way to get better at using all the stone and put less of it down the drain.