stropping 10v and k390...

mycough

mycough

Joined
May 20, 2007
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I am hoping for a simple answer to this question... Are these steels unaffected by the classic black, white, and green progression of stropping compounds? He who shall not be be named has said any higher vanadium percentage steel is not really refined by these old standbys. I have a strop charged with 1mic CBN on the way but want to know if all my old strops are useless. I will hang up and listen to your answer. Thanks, Russ
 
Well with 10V having 10% Vanadium Carbide and K390 having what... 9%..? They are definitely up there in term of abrasion resistance. What it is going to come down to is the size of the carbides in the steel. Heat treat and tempering will affect carbide size and therefore one heat treatment could make a steel much more difficult to sharpen than the other even given a similar RC.

So the compounds you mentioned are not hard enough to abrade Vanadium carbide , so when you get to a compound that is the same size as the VC than that will be as far as you can go without going to CBN or Diamond stropping compounds. Again this is determined by the maker in the heat treatment process.

Once you go to CBN/Diamond this becomes irrelevant.

With the levels of carbides in the steels mentioned I would hazard a guess that they are quite large compared to something like CPM3V , nothing you can do but try it out and see for sure. Your going to like the 1u CBN , out of curiosity what are you preceding it with?
 
IMH2CO

CPM 10V & K390 both are Powder Metallurgy so their carbide size are mostly preformed at size around 1-4micron. Let's assumed ht wasn't poorly done.

Pre-strop edge could use some clean up from various stropping compounds (white/black/green/even-pink). However excess of cleaning with soft-abrasives meant abrading away the steel matrix supporting these carbide.

How's stropping with diamond/cbn abrasive, keep in mind that dia/cbn will abrade steel matrix ahead of carbide because of matrix softness. Also think how a partially embedded or free rolling dia/cbn collide with carbide size between 1-4 microns. Depend on collision/impact force, the proportion of abrading vs dis-lodge carbide will taken place. Remember now, at this stage of refinement you don't want to dislodge carbides that have strong matrix support and will serve as the cutting edge. What size is best for abrading and minimal dislodging? I think 0.25um and smaller works better.
 
I am now getting confused. I have all the edge pro stones to 1000 grit. I recently added shapton glass 500, 1000,4000,8000. I thought you didn't want to go too small because of the vanadium, and I don't anticipate buying any finer stones soon.
Someone I respect suggested a dedicated CBN charged strop and it is arriving today and I have more 1mic CBN coming from Schwartz. I get a little bristly when the HT is questioned because it is Big Chris and Dave at OTK. I don't have any "Blunt cut" customs but I am guessing my knives at least in the same ballpark.
I like high tech steel and just want to be able to maintain it without sending it off to Kentucky and Arkansas twice a year. I am a chef and can sharpen a bit but I need a routine for these fine knives.
 
I was reading Phil Wilson's website last night. He uses these steels a lot and recommends a silicon carbide (Crystalon) stone for sharpening them.
 
Buffalohump said:
I was reading Phil Wilson's website last night. He uses these steels a lot and recommends a silicon carbide (Crystalon) stone for sharpening them.
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I know, I have the two grits of crystolon and it seems as though he gets great results with out going to sub atomic metiorite transubstantiation methods. It sounds so easy and that adds to my confusion. I just want to keep them as sharp as they were when I got them, within reason. Russ
 
Phil and Jim Ankerson both will load a stop with the swarf from the SC stones and use that for stropping the high wear steels. It removes the burr and leaves an aggressive edge.
As for what guys have on hand, I use a loaded belt on a small sander with green compound for burr removal. It is not as efficient at cutting 10V as it is O1, but it will refine the edge if enough time is invested. I typically use a Silicon Carbide based paste for stropping and it performs extremely well on everything I have sharpened except for S110V. I had to use a CBN loaded strop for it.
 
Good stuff Chris! Just emailed you before I saw this. The green monster has been active lately and is still shaving hair. Have been stropping conventionally but my CBN is out for delivery today. Thanks for chiming in, loving the M390 piece as well. Russ
 
Silicon carbide can be used on these steels. Some of the vanadium carbides can be worked on AlumOx, but that implies AlumOx with a high purity and Va carbides at the low end of what they are capable of achieving. Diamond or CBN will make this a lot easier, but since they can be sharpened on a SiC stone, they can certainly be stropped on SiC powders. With whatever abrasive, I have to imagine a hard backing like balsa etc will give best results to minimize the effect that Bluntcut is describing - loose grit attacking the steel matrix faster then it abrades the carbides.
 
HeavyHanded said:
Silicon carbide can be used on these steels. Some of the vanadium carbides can be worked on AlumOx, but that implies AlumOx with a high purity and Va carbides at the low end of what they are capable of achieving. Diamond or CBN will make this a lot easier, but since they can be sharpened on a SiC stone, they can certainly be stropped on SiC powders. With whatever abrasive, I have to imagine a hard backing like balsa etc will give best results to minimize the effect that Bluntcut is describing - loose grit attacking the steel matrix faster then it abrades the carbides.
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Thanks for that. I was watching one of your videos last night and all of a sudden I was down stairs with a piece of 500 grit wet dry on a poly cutting board sharpening an old victorinox paring knife. My wife thinks I am nuts and she may be right. I may invest in your system soon, seems like a cool idea. Russ
 
mycough said:
Thanks for that. I was watching one of your videos last night and all of a sudden I was down stairs with a piece of 500 grit wet dry on a poly cutting board sharpening an old victorinox paring knife. My wife thinks I am nuts and she may be right. I may invest in your system soon, seems like a cool idea. Russ
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Do, I got the washboard and love it!
 
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