Which mirco-bevel/polishing question

i wasnt thinking anyone was talking above me, quite the opposite everytime i have asked anything i have always been answered with respect and more or less just people hear generally seem to want to share there knowledge and be of help. i honesty enjoy reading everyones responses, takes awhile because i think if you are going threw the time to answer i should at least try to find out what i can on my own. sooo, just wanted to say thanks, and i am REALLY glad i didnt try the dishwasher/ice water idea.
 
dieselpusher6262 said:
i am REALLY glad i didnt try the dishwasher/ice water idea.
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it wouldn't have done anything but wasted your time. kershaw/ZT has a pretty good reputation for heat treating, are you unhappy with the performance of your knife?

what are you using to sharpen your knife? you listed alot of different grit levels.
 
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Couple quick thoughts: first, steel can definitely be annealed after it is hardened. The process involves heating to a specific temperature and cooling slowly at a defined specific rate, which depends on steel type, thickness, and desired level of annealing. Steel can also be heat treated and quenched multiple times in a row without annealing in between, but this stands a much higher chance of cracking.

Cryogenic treatment is fairly well understood, but not nearly to the same extent as heat treatment, which has been studied for quite a lot longer, as Me2 stated in his post.

It is also possible to easily heat treat steel and end up with varying hardness. When steel is heated, it warms from the outside in, so if the steel is not held at the desired temperature for long enough, it will be cooler in the center than on the surface, which will result in differing hardness from outside to inside. Heating via torch or covering pars of the blade can also keep parts of the blade cooler, resulting in softer portions of the blade.

Also - diesel, I applaud your respectful thank you above. It is nice to see someone who appreciates the answers everyone tries to provide for once. For my part, you are welcome, and bravo!
 
Jim, I'm not real sure how that clears anything up from my post, it seems you are repeating your earlier post. I see where you could have gotten confused as to my meaning since I used "heat treated and quenched" in the post above rather than "heated and quenched," but other than that you are merely reiterating. Also, several well respected knife makers use multiple consecutive heat treatments on their blades to refine grain size to its smallest potential; multiple stage tempering is not the only option. Indeed, many actually do multiple heat treatments, multiple cryo, and multiple tempering stages.

Edited to add a "for instance" since you seem to be in disbelief of this point:http://www.edfowler.com/thesteel.html
Read the section where he talks about grain size and multiple differential heat treatments.
 
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While there are a few things there I prefer to do differently, there is no doubt Ed is one of those who is after that last drop of water from the rock.
 
That's for sure. But like you mentioned earlier, there is always something new to learn with enough experimentation and time spent.
 
i found a machine flat granite block with a steel rod going threw the center, i think he said is was for a precision dial indicator. well where i dial used to go i mounted a round wood rod, 3/4" or so. because the clamps around the steel rod are adjustable i move them up or down to get the angle i am trying for, check it with my cell phone (protactor app) then use two small clamps and clamp the sandpaper in place, thought i was doing pretty good, choose to reprofile to 13 degrees and went threw all those grits (what was werid is this last time i really didnt get much of a burr). thought i was going pretty good, all i had to do was hold the blade prefectly flat and go down the sandpaper, used the sharpie (actually a dry erase marker so i wouldnt screw up the finer and more expensive mirco-mesh sandpaper) and made sure i was removing material from the entire edge. went down to the 12k and then stropped on leather with white rouge, then plaining leather. as it turned out yesterday when i went to place the mirco-bevel at 17 degrees starting at 15 micro honing paper i was not just hitting the very edge but the entire side of the bevel. any ideas on what i am doing wrong? are my primary angle and mirco-bevel to close. the zt was fine as it was, but i can never leave well enough alone. and that knife was what i first used to learn how to use a beltsander on. well the beltsander won and i removed 60% of the blade material. i sent it to Kershaw hoping to be able just to purchase a new blade, maybe even at a discount but they sent it back with a brand new blade (thought it was all black, no markings. also has anyone had a replacement blade that all the lines in the blade where off? if you looked at one side of the blade the top center of the blade (both thickness and dept where different, i thought kershaw maybe placed blades that didnt pass quality control on there warranties, but no after talking to them they said there blades where all black so they could use them in any knife, only thing i didnt understand was i didnt think there was another kershaw/ZT knife that would use the 300 blade) anyways not liking that the beltsander got the best of me, i decided to try again and very carefully thinned the blade enough to make both sides match, there was alot of hand sanding in there though. wrapping everything up, i ended up with a much thinner blade, kind of similar to a large BM flipper i saw. Oh the first reprofile was done with a homemade jig that clamped the blade and a rod. I will try and post some pics. i am diffinitely getting sharper but after all this work i am going to carry it as an after work knife, something scary sharp, profiled down so i could easily shave with it, but not much of a work knife. i am working on getting some pics right now.
 
eKretz said:
That's for sure. But like you mentioned earlier, there is always something new to learn with enough experimentation and time spent.
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+1. that's why im here. im am not afraid to be proven wrong or get corrected as long as we all learn more in the end.
 
dieselpusher6262 said:
and then stropped on leather with white rouge, then plaining leather. as it turned out yesterday when i went to place the mirco-bevel at 17 degrees starting at 15 micro honing paper i was not just hitting the very edge but the entire side of the bevel. any ideas on what i am doing wrong?

are my primary angle and mirco-bevel to close. the zt was fine as it was, but i can never leave well enough alone.

and that knife was what i first used to learn how to use a beltsander on. well the beltsander won and i removed 60% of the blade material.
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i think your problem is with the white rouge. i was doing testing on my buck vantage pro (s30v) and all was well until i stropped on white rouge. for some reason my edge got duller (i am fairly new to stropping but not to sharpening). the only thing i can think of is that because s30v has a high vanadium carbide content (4%), the abrasives in the white rouge are softer than vanadium carbide and that might be causing the problem. i recommend trying a harder abrasive paste (like boron carbide or diamond).

i always tell people: "unless you have alot of experience sharpening and a decent amount of metallurgy knowledge, stay away from grinders and sanders". you are lucky kai/kershaw/ZT are a great company. when i use a sander or grinder i always keep a tub of cold water near me to constantly cool the blade. when i use a grinder, i turn it on for only a second or two so the wheel is going about 25% of it's speed. i grind in steps, as the wheel almost comes to a stop, i repeat the process. the slower the wheel spins the less heat is generated (plus i have a steady and consistent hand).

you are using alot of grits that are really close to each other. you could skip a few steps and save yourself some time. make sure you wipe the edge off between grids so you don't carry a coarser grit to the next stage.

p.s. have you considered using water stones?
 
what ed found out is similar to what i do to my knives. i learned this all on my own by experimenting with the steel before i ever made my first knife.

i do a second heat treat to my knives since the steel i use is already hardened to an rc of 56. i work the steel as is and i have never annealed a piece in order to work it.

i have a certain color i watch for and hold that color for several minutes. (i am using a cutting torch with the oxygen turned almost all the way of and a real gentle flame not over 6" long if that.)

i try for an rc hardness between 63-65 and i dont temper my blades. whatever rc hardness the blade is that is where it stays. i have made my knives this way for the past 20 years.

i have a buddy with a skinner that has skinned 10 deer so far and it still shaves. his s&w folder he used to use would only do a few deer before needing resharpened.
 
i do have some water stones but this whole little obession is because of the recurve. i was never able to get it very sharp, and the idea of using the corner of the stone doesnt really appeal to be because it seems as though each stone would wear differently causing the angle to change, and i dont have the talent yet to make the suttle corrections nessecarry.
 
It didn't register with me that knife has a recurve. Try www.congresstools.com. They have round and triangular stones all the way to 1200 grit, and very coarse grades as well, in various diameters. They are primarily sold to machinists for hand polishing hard to reach places, but they work for knives as well.
 
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