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S30V badly Etched Using BKF Need Ideas

Discussion in 'Maintenance, Tinkering & Embellishment' started by Tracing, Dec 7, 2018 at 10:51 PM.

  1. Tracing

    Tracing

    5
    Friday
    I tried for about 2 hours searching for a possible solution but couldn't find much. Hopefully someone can save my hide here.

    Could someone tell me how to clean up etching caused by Bar Keepers Friend or maybe point me a good shop that I could send the knife to?

    The knife is a Sage 1 S30v. I've only ever used BKF for cleaning Sharpmaker stones and never on the knife. I had never even bothered reading the ingredients, something I usually do, or the key part about not leaving it on beyond 1 min. I had cut some exotic plant stalks without cleaning the blade after until two days later. It caused a haze or patina on the blade like I had never seen before on this knife. I decided to use BKF but left it on too long and one time too many before realizing I was making it worst!

    Now it's etched to the point its annoying. Cloudy hazed looking. I have some polishing compound bars in 5 different grit from black to green and even the black (roughest one) would not do much when tried in a small test area using a dremel with buffing wheel. I really don't want to try any more crude methods unless I know it's been tried before. Have not tried 0000 steel wool yet and doubtful that even work.

    S30V being such a tough stainless unlike a stainless sing, it would seem that to even budge this would have to be put on a belt sander by someone who has experience doing so and without ruining the factory engravings.

    Any help much appreciated
     
  2. Sergeua

    Sergeua

    866
    May 1, 2016
    Time to get a stone washed look added on to it.
    I wanna see a pic plz
     
  3. Tracing

    Tracing

    5
    Friday
    [​IMG]
     
  4. Sergeua

    Sergeua

    866
    May 1, 2016
    I'd sand it with 800grit sandpaper, keeping with the direction of those vertical grind marks you have there already.
    clamp sandpaper to a piece of wood somehow, sprinkle some water and go back and forth with the blade on it's side.
    Try not to dull the edge, otherwise you just going to have to sharpen it.
    It worked good on my spyderco mantra. The m4 got a patina I didn't like so I took it off. I wanted it to be more even.
    It is now naturally getting there.
     
    hughd and David Martin like this.
  5. Mo2

    Mo2

    Apr 8, 2016
    Not sure if it's too late or not but baking soda is what helps neutralizes bkf.
     
  6. Sanding is likely the only thing that'll clean the etching up. Linear passes in one direction only and parallel to the factory grind lines, using a sanding block. Something around 320-400 grit SiC wet/dry paper is where I'd start, more closely emulating the factory finish. S30V is pretty wear-resistant, so the finish left by sanding will be finer than if done with the same grit on simpler steels; hence my suggestion to start a little bit coarser. Higher-grit sandpaper will have a bit of a tougher time with S30V's carbides as well (it doesn't sharpen easily at higher grit, with SiC paper), so sanding generally goes better at somewhat lower grit on such a steel.
     
    Sergeua likes this.
  7. Tracing

    Tracing

    5
    Friday
    Yeah sanding it had crossed my mind but wanted to hear if anyone else would suggest it or tried already. That sounds like the best option but may be the second one I try. I briefly hit a very small area with 1000 grit wet/dry paper as it was all I had last night. It would move some steel (could see it clogging the paper) but as you could image at such fine grit it would only polish the peaks which was insignificant with the deep brushed grind on these Sage S30V. It would have to be around 400 as Obsessed mentioned. Could be high as 800 too but we will see. The right grit should allow to get down in those valleys without actually smoothing the finish too much. Hopefully if I decide to try this method I can stay away from the Spider logo and feather around it to look right.

    I found a post where a member gives instructions on removing oxidation and mentions BKF patina using 0000 steel wool and Flitz but it seems doubtful it work on steel with such a rough grind on it's face. I may give that a try first it being more of a mild approach with the Sandpaper being a nuclear option. Here's that guide https://www.bladeforums.com/threads/blade-oxidation.1179021/

    It may be a day or two but I will post what I come up with a "after" photo. First time posting here but not new to the great information on this site.
    Thanks for the advice everyone.
     
  8. The removal of patina (oxidation) with polishing paste or BKF and steel wool is only a surface fix, as the oxide is much thinner and much less wear-resistant than the etched steel on the S30V blade.

    The etching of the S30V has actually altered the surface texture of the steel, sort of like pitting would do with corrosion (which is what the BKF did to the S30V, technically). So, with one method, only a thin and not-very-hard dark oxide is being removed from the surface of relatively unaltered steel; with the other method, the steel itself, with it's uber-hard carbides, has been permanently altered by the etching. This is why it'll take some sort of aggressive sanding or grinding to fix the etched steel, whereas the oxide on the simple carbon steel is much easier to remove with metal polish and some relatively light scrubbing.

    A patinating process on simple carbon steel will actually pit or etch that steel microscopically. But again, with such a treatment, the alteration to the steel is usually much more shallow and occurring in steel that's much less wear-resistant, and therefore much easier to 'fix' with some polish and elbow grease. Compare that to a chemical process capable of deeply etching stainless steel (which S30V is), and how much work it'll take (sanding/grinding) to fix the damage resulting from that.
     
  9. Tracing

    Tracing

    5
    Friday
    Agreed. I came across a new package of 400 paper I had at home. I tested on a small Buck blade that has the same textured grind as the Sage although less wear-resistant but it took little effort to remove some surface scratches and cleaned up nice. It left a very slightly less of a brushed appearance. Being the S30V is rougher texture 320 might do the jon better so I'll pick up some and give it a go. I've abandoned the steel wool idea.

    Taking sanding paper to a mid to high-end blade's face is something I normally wouldn't think about but I have the confidence now it will turn out fine. It's purely cosmetic and I'll likely never get rid of it especially after this.
     
  10. JJ_Colt45

    JJ_Colt45 Gold Member Gold Member

    Sep 11, 2014
    If you can't get the results you want ... you asked about shops you could send it to ... Josh @ REK Sharpening does great work ... everything from sharpening to different finishes or regrinds and much more.
     
    razor-edge-knives likes this.
  11. eKretz

    eKretz

    758
    Aug 30, 2009
    If you want a nicer result, make sure you use a backer for that wet/dry. Use a steel block or something and wrap the paper around the corners so you can get a grip on it and keep your fingers away from the knife edge.
     
  12. Might even consider 220-grit. I've cleaned up some simpler stainless blades using it, and it always comes to me as a bit of a surprise that the resulting finish looks finer or cleaner than the grit rating might imply. I think a lot of factory 'satin' finishes are actually done with aluminum oxide belts in the 150-220 range, and they still look good, due to the uniformity of the grind lines and maybe a little bit of finish buffing afterward.
     
  13. Tracing

    Tracing

    5
    Friday
    Will do, thanks
     
  14. eKretz

    eKretz

    758
    Aug 30, 2009
    One big difference between a fellow doing this at home and a factory making knives is that the factory normally will use abrasive belts for quite some time. This can result in a markedly different appearance in terms of finish even if you use the same grit that the factory did - since the average fellow at home would probably go out to the store and buy brand new, fresh sharp abrasive paper while the factory is using older dulled abrasive belts for most of their knives. The net result is that the factory finish will look and feel smoother and brighter in most cases even if you use the exact same stuff they did. Of course you can make yours look even better by switching to a finer abrasive than the factory used.
     

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