Wow , has it been three weeks since this was up ? Seems like a few days .
Anyway I accidentally on purpose made a discovery.
I have a Case Trapper with the carbon steel blade that I have been developing a specific intentional patina on.
Specific = blue color using GOLDEN kiwi and even more specific using only the flesh right next to the skin / back side of the skin .
Intentional = putting pieces of the skin on both sides of the blade and massaging them on until they kind of suction onto the hollow ground blade ( takes some doing). Leave the kiwi on the blade for hours ; move it some every half hour or so so as few lines as possible form in the patina.
Over various sessions I have gone so far as to heat up the Kiwi or warm the blade with a heat gun after I remove the kiwi < 200° F .
This was all working great until . . . I got greedy .
The blue was really blue and it was pretty darned even without hardly any lines !
But I told my self : One more session. I could make it REALLY BLUE !
So I gave it one more go ; same as above.
Turns out I was using regular old GREEN kiwis and my patina turned black , got black lines all through it and when washed and dried even had a nasty gray / white over cast.
faaaiiiiillllure !
Repeats with GOLDEN kiwi couldn't fix it.
Must strip patina but how ?
I was surprised months ago that the Case knife polish / Flitz couldn't touch another patina I stripped.
What I finally used back then was Red 3M pad.
What I didn't like about that was it took too long and over hung the edge and dulled it.
Today I had surprisingly quick success with the following. It wasn't perfect and I will get to that but I thought it could be very successful for some and totally non toxic and always on hand once you get it.
If you are not familiar with the yellow Norton water stone in 8000 grit I recommend investigating it and peoples comments here on BF for sharpening. It is a jewel for the less exotic steels; forget it for vanadium alloys above a couple of percent ( great for Case's CV blades ).
anyway
I have a set of the Norton water stones for sharpening (forget the gray 220 it's only good for a door stop) but the others are freekin' excellent.
I have another set of the same that I cut up to use for hand held sharpening and polishing the sides of blades in a slow and half fast way ; see ancient sword Polishing technique .
The other thing you need is a nagura stone or rust eraser rubber like pad. I used a natural nagura which is almost unobtainable now as far as I can tell.
I simply took the finest Norton 8000 stone piece , soaked it a bit , rounded the end on a diamond stone so it could get down into the curve of the hollow ground blade and rubbed across the bladed back and forth from spine to edge but never contacting the edge. When the stone loaded up with black I cleaned it with the nagura. Went astonishingly fast. This is a stone that normally leaves a mirror polish on an edge when sharpening and the Case Trapper comes from the factory with a mirror like polish so that's why I used it.
If your knife has a lower polish or belt grit finish then use a more coarse stone.
Two final things of note :
the black stuff coming off my blade oddly seemed to travel up the sides of the stone to areas that never contacted the blade and then strongly clung there
and
with this ultra fine stone it did not remove the deeper " etched in " lines of patina which were pretty subtle. I think if I were to go after those with the white 1000 Norton stone then bring the polish back up with the 8000 I could get them out. So that was where my results were less than perfect.
I will be fine with some subtle lines of dark gray way down in an almost consistent blue patina so I'm leaving the lines.
Nothing much to add beyond that at this time .
