Sandvik 12C27 vs ANDE Rope | Petrified Fish PF719 Knife Fine Edge

[@lars43771]

You are definitely dealing with a high % of retained austenite. 12c27 done right, would indeed be a joy to sharpen and deburr, this clearly is not. What i’ve found to be the quickest way of dealing with this is; grinding the edge to an apex on a coarse or medium stone/plate, then try to somewhat reduce the burr with a few alternating passes. After that, you want to joint the edge (drag across a fine stone at a 90 degree angle) and knock the burr/apex completely off. From there on, jump to a finer stone and proceed to do just alternating passes (not letting a new burr form), until you’ve apexed again. After that, stropping with Stroppy Stuff 1 and then quarter micron on leather or basswood. Sometimes, stropping on a piece of CLEAN (this is important, as to not round the apex) hanging denim/canvas will get rid of those last little bits of micro burr that seem to keep hanging on, with just a flat stropping surface.

[@stroppystuff641]

This is gold btw

[@homeslicesharpening]

Awesome - thanks Lars! I filmed the follow up videos a little while ago - but I will definitely try this now in the present and see if I can get the steel to cooperate!

[@knickly]

Just a shot in the dark here - it might be worth revisiting Dr Kraichuk's recommendations on positive versus negative burr removal. I also recall Roman has mentioned deburring by abrasive stropping on the flesh side of leather. I've been wanting to try freezing a knife after forming a burr and before deburring to reduce the ductility.

[@homeslicesharpening]

Ooooh... That's a fun idea...

[@PBWilson1970]

I also have this knife and love the design and especially the way it snaps open like you mentioned. Zero drag, just a push on the thumbstud and it's open in an instant. I bought it for the looks and hoped it would be a daily user, but the very thin blade thickness keeps it in a lighter duty category. It's a fantastic gent's knife, but the thin handle keeps it from being comfortable in my hand for more outdoorsy wood-whittling stuff. I use a set of DMT diamond stones up to their ex-fine (which I believe is 1200 grit) and follow with light stropping on leather. It doesn't hold quite the same edge as some of my other Sandvik knives (another Petrified Fish and some Moras) whihc may be because of a burr (I haven't looked too closely) or perhaps because of a rather fine edge angle. Maybe I'll try a more robust angle and see where it leads me. I hope you give this a try with your dual grit edge. I'd like to see the results.

[@homeslicesharpening]

Interesting! Thanks!

[@danielbottner7700]

My calculations to remove stubborn burrs . . . - A progressive two pass strop combination should yield results. - A relatively fine grit & relatively hard surface strop should work best. - First pass . . . Strop perpendicular to blade centerline. - Second pass at . . . Double cutting edge angle burr is folded into. Your success will depend upon optimization of pressure applied & strop used. I will send drawings . . . Thanks for sharing !

[@homeslicesharpening]

Beautiful, thanks Daniel! As I am at my father in-laws' house in WA at the moment - helping on the farm after his hand injury - I will have to wait until I return home to this knife to try it, but I will tinker around with this method

[@danielbottner7700]

Relative incremental testing angles considering the . . . atomic structure of metals are in the 5º to 20º range. Knife sharpeners seem to have come to a consensus of 17º... as a starting point. This seems plausibly correct looking at the geometric models & calculations.

[@homeslicesharpening]

Interesting!

[@CSGraves]

I too will be eager to find out how best to resolve that mystery burr issue. I know when I get desperate to remove a burr, I use a carbide scraper... one of those freehand type tools, not the pull through sort with preset angles. Will that be any use in your scenario? Not a clue! I do like the look of that Petrified Fish though. I think that model also goes by the name 'Patte'?

[@homeslicesharpening]

Yeah, it's a fantastic design - I hope I can salvage the edge.

[@sabelfechter7136]

Nice bladeshape. Shitty to deburr steel is one of the things i absolutely hate the most, luckly rarely had to deal with it, but once a really bad case. Aside from that, got my hands on a Magnacut UKPK now, was unhappy with the factory bevel, but the flat grind is good as its true flat. And its ergonomics outstanding. I made a very shallow convex transition of like 6->12dps, a 0.1mm 15dps microbevel, and i touch it up at 17dps on a wood strop. Its insane, even if it goes a bit dull, it gets stropped back to *free hair popping* on wood. The angle change minimizes contact area and maximizes stropping efficiency. Due to the wood i dont have to worry too much about the angle being changed with higher pressure stropping, compared to other media. But its a bit hard to find good wood for it. The sizes i like are: The portable 15cm, to hold between thumb and middlefinger+ringfinger. The standart 30cm. But people have no idea what they miss out on if they dont have a 60cm strop, esp with decent wood, it maximizes touchup efficiency during work that quickly dulls the apex but doesnt ruin it, complete gamechanger. Not a hot take, Magnacut is my favorite steel, in concept and practice. Stability/Corrosian Resistance/Abrasion Resistance/Sharpenability Rambling over.

[@homeslicesharpening]

I enjoyed the rambling... Thanks for stropping by. I mean stopping by... Dad joke 😆

[@thiago.assumpcao]

I have one knife that fails to shave hair no matter what stone I use. I tried edge leading, scaling down pressure, strops and smooth honing rod. After I gave up on it I managed to get a shaving sharp edge using a ceramic honing rod. No idea why that worked but it did.

[@harperexplores9349]

It adds back some toothiness to the blade

[@thiago.assumpcao]

​@@harperexplores9349The honing rod edge feels something like a 3K stone. This knife doesn't shave out of a any stone, including 300, 1k, 3K, 6k.

[@homeslicesharpening]

Yeah, this has perplexed me as well!

[@Yy-ig6fm]

Maybe it's a bad heat treat and it's in the lower end of it's hardness range making it too ductile to sharpen properly. If you have another knife in this steel you could compare them head to head.

[@thiago.assumpcao]

Soft steel is harder to properly deburr but even 50HRC knives can pop hairs. If it doesn't acheive this level of sharpness it could be grain growth, retained austenite or some issue with sharpening technique.

[@homeslicesharpening]

Thanks guys! I will keep you posted!

[@harperexplores9349]

Have you tried to raise the bevel up to 24 degrees? We are so trained to try to reduce this to 17-20 but with this steel the steep edge will give you a burr with definition.

[@homeslicesharpening]

Interesting thought!!! I should try it!

[@CNYKnifeNut]

Try plateau sharpening it, with no stropping. Edit: thats my go to for poorly heat treated, soft m390 that can get huge foil burrs. Sounds like youre dealing with similar issues.

[@homeslicesharpening]

Nice! Thanks for the tip. I have already filmed and published the follow up, but I will look into plateau sharpening, thanks!

[@samhenderson2947]

I saw a trick that I've used to some effect. Either acut a piece of hard wood and slice into it perpendicular or very lightly do the same thing with a stone. Would love to hear if it works for you.

[@homeslicesharpening]

I'll try it out, thanks!

[@sstein49]

320 on side A 600 side B , naked leather board strop , then maybe 1 micron basswood That stuff is about 52 -54 hard

[@homeslicesharpening]

Yeah - I would believe it. I'm writing down your suggestion. I am stateside now, helping my father in law at his farm (he lost a finger in an accident a month ago) but will try your suggestion when I return to NZ!