Knife #6 and Sharpness issues

southriv

southriv

Joined
Feb 28, 2002
Messages
751
Well, Here is my sixth knife. O1 steel, 3/16" thick. 9-1/2" overall- 4 –5/8" blade. The handle is stabilized black ash, with a reindeer antler section and nickel and black spacers.

This one went real smooth until I did the last step – putting an edge on. Needless to stay, it did not go well. Nervous as hell, I reground the hollow section, starting with a 180 belt. One pass –cool the blade, etc up to polish and a new edge – a scary process.

I made 20 blades after my last (the fifth knife) . I kept 10 and this is the first of that bunch I have put a handle on. The remainder are 01 and 440C. I’m getting more comfortable with grind, heat treat , finish and handle work.

I’m still a bit perplexed about this "scary sharp" obessesion I keep reading about – it has almost caused me to ruin more than one knife. On all my finish knives and test knives to date (all of 01 steel) I can get a respectable edge that will hold up, cut everything, do the brass rod test, etc and sometimes shave hair (which seem to be the measure everyone gets hung up one), but I suspect I don’t have "it" with the sharpness based on what I hear on the forums. On the other hand, I test all my knives cutting ability beside a Randall Model 8. It won’t cut hair, but I like the way it performs.

I have tried old belts, new belts, stopping at 220, 400, 600, knocking the wire off with a couple light passes on the buffer. The results do not seem to differ greatly. I temper with two draws at 375, separated by 24 hours in the freezer. I can’t think of any other variables (I am also careful not to overheat when grinding the tempered blade) other than to how the results differ with the other steels I will be trying.

Bottom line, I’d like to be able to sell a couple blades later this year, but I’m getting nervous about meeting all the "requirements".

Bob

http://www.southrivermodelworks.com/page12a.html



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FWIW...
you certainly have got the 'pretty' part down pat :)
That is a good looker!
 
Bob take it down to a 15 micron at about a 20 deg.
angle you should see in the light a very small wire,
strop it off with a leather strap and you can buff
it just a little with green chrome rouge. I'll
run the edge though a piece of wood shaving it to
get the wire off some times too. if it wont shave hair
now we'll have to back up a few steps
to see what's going on with your heat treat..
_ BTW_ that knife looks real nice...
;)
 
You continue to inspire me. Metal work looks real good to me and that 'ash', I had no idea how good it could look.

I have been reading that the second temper on O-1 should be 25 degrees less than the first.

I hope I learn to grind as well as yours looks.

Roger
 
Bob that is classic and beautiful. What a nice knife!

As to the edge, I think it's something to do with edge geometry. When I can get one really hair popping sharp it usually is a fairly deep flat grind where I put the edge in with a slack 400 belt, and buffed it glossy. Edges like that are fun to play with but may not be all that practical; I think they dull faster in things you normally cut like hairy hide or cardboard (all other things being equal. ;) ).

Dave
 
Dan & Dave - My blade is pretty heavy - at 3/16 thick and not a very agressive grind, so edge geometry may have something to do with it.

I do know that once I get to the best level of performance I can, it seem to stay there without dulling. The best I have seemed to come up with is to finish the edge with a 400 belt. and a couple very light passes on the buffing wheel with light green rouge.

I am also seriously considering Dan's suggestion of looking back at square one - heat treat. I t may be also possible I screwed the pooch here and ended up with a soft edge - then again, it seems to flex and return on the brass rod - so who knows....I know my curiousity will never be satisfied until I can see what it takes for me to get the more (or the most )out of this
steel.

Roger - if you like that ash wood, you can get some at
http://www.stabilizedwood.com/

bob

.
 
Take the 'period' off the end of the link to the '/page15a.html' link. That's why the link doesn't work.

RL
 
Southriv,
That is one hell of a nice looking knife! As far as sharp goes, have you been considering the geometry of the edge? I bet you its just too broad. If that's not it, than the only other red flag may simply be your technique. Sharpening is an art form in its own right. My two cents.

-Jason
 
About popping hair think about the design of a straight razor or any other razor. Very thin very low angle edge.

Maybe its your hair. Try your wife's or girlfreinds if ya got one. Best wait till she's asleep.

Sharpening engenders lots of prejiduces because people find/learn the ways that work for them and then figure its the best way.

I for one, as a reforming woodworker, am aghast that anyone would sharpen on a sanding machine or buffer. Get yourself the most expensive set of japanese water stones that you can find and keep them flat.:)

Try here too.
http://www.bladeforums.com/features/faqsharp.shtml

Oh Yeah - purty knife!

Lynn
 
There is nothing wrong with your knife. The geometry of the grind will not allow it to get to the sharpness you are seeking. You have what is called a "working edge". Not as sharp as a razor, but will stay working sharp and last longer than a razor edge. I prefer this edge on everyday working knives and large field knives. You might try this same grind on thinner stock, 1/8-3/32 to be able to get a sharper edge. Your knife is my kind of knife, good looking and hard working.
KEN (WWJD)
 
Live and learn, experience , experience…..doing 20 blades in a month has given me the beginnings of knowledge on a variety of issues. As for sharpness, many made comments about edge geometry. Well , I went back and looked at blade thickness on my knives (both initial and ground) and measured the angles of the edges… I can say that those comments were right on. I seem to have a variety of cutting edges – from razor sharp to working edges and they are all durable. My latest has a good working edge. I have a companion to it ( a test knife) in 5/32, thinner edge and with an edge angle that is 10-12 degrees lower– it can shave hair and slide through paper…. I think that comparison says a lot.

In my knife collection , the best cutting knife is Finnish Puukko . It is flat ground at a low angle with the edge at the same angle. Next is a South African knife of 1/8" 44C with a very thin edge.

I had a talk with my 01 steel mentor, Dan Gray (Graymaker) and after comparing notes we came up with what all you very observant folks came up with – plus some other thoughts about 01 heat treat, etc. Thanks for all your comments – this forum is the best teacher I have.

Bob

http://www.southrivermodelworks.com/page15a.html
 
Bob,

I agree with Ken ( ragnoor), theres to much emphasis put on scary sharp, whats that all about anyway. Thats a great looking knife and I would want an edge that will cut and keep cutting instead of a thin super sharp edge that won't if you work it hard. If it passed the brass rod, your heat treat sounds awfully close to right, might adjust temp down just a little but then your blade will become a little harder to sharpen. Consider your blade size and intended use when sharpening, filet and finesse type blades thin edge with less angle, hunters and working blades thick edge and more angle, like a chisel, takes a lot of abuse and still holds a great edge.
Another thing Bob, test your blades for cutting ability useing rope, hack on 2x4s and such for testing edge strength, and break a few in a vise doing 90 degree bends to test for over all toughness and to check grain size. If your blades pass these tests to your satisfaction, then sale, if you still have doubts about the quality, give a couple to your friends and say I need these tested and tested hard, chop, beat, slice and thump on things within reason and tell me what you think. When they come back and say man, thats the best knife I ever had, you'll know its time. ;)

Hope this helps a little

Bill
 
Bill - extremely well spoken advice. I have been following your suggested path and have had similar thoughts.....Out of twenty blades I have ground in the last month, 10 have been reground a variety of ways, tested on rope, wood and then "sacrified" to a bending test. The remains get examined under a stereo microscope. I'm planning to meet with a couple of hunter/handyman friends in the near future and am going to give them each a "gift" - we'll see what they can do.


Bob
 
Bob,
Stop it! Your starting to scare me, If I recall I don't think my 20th knife looked this good. Keep up the good work, then can you give me lessons!!:D :D :D
 
Bob: The knife looks great. I wouldn't get too obsessed with sharpness just yet. You are right to be thinking about all the elements that go into getting a knife sharp-heat treatment is the fundamental key. If that's not right, nothing else matters.
Beyond that, the execution of the rest of the blade (grind style, edge thickness, bevel angle) are really up to you. If the knife is performing well for you, and, you like how it cuts, then, you're all set.
Based on how you describe your technique, you are sharpening about like most guys. Are you using a slack belt, and, are you contacting the whole edge bevel with each pass?
Sharpening well has a lot to do with practice and experience-your knives will get sharper over time if the HT is good. Just stay at it and it will improve.
There are SO many variables that affect how sharp your edge will get-the buffing wheel, the RPM, the compound, etc.
It takes time to figure out what works best for you. That's part of the fun.

Stay Sharp,

RJ Martin
 
i concure that each blade design and edge is differnt, also shaving is a push cut, sliceing is a pull cut. shaving hair is great! if your shaving hair! the constant curve in your design makes for a great pull cut. the looks of that knife have me fired up this morning to get into the shop!
 
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