Sharpening new or slightly used knife

D

divebuddydave

Joined
May 17, 2004
Messages
46
When sharpening a new or reasonably sharp knife, do you have to get a burr again? At what point do you know it is time to get a burr or whether it is just OK to "touch it up"?
 
Right now, the search is not working for me for some reason. Get a "page not available" warning. I have searched previously, but can't seem to find my exact question answered. I understand about raising a burr and then polishing it, but what I am not sure of is that if everytime I go to sharpen a reasonably sharp (not dull or worn) knife, must I raise a burr again to get it really sharp. I read about people saying not to let your knife get too dull and then just "touching it up". I'm not sure what the "touching up" procedure is.
 
divebuddydave - there are differing opinions, of course, but the majority seem to agree that raising a burr when doing a full sharpening is good practice. However, when touching up a reasonably fresh edge that has only seen limited use and no significant damage, most seem to feel this is unnecessary.

So the real question is, when is a full sharpening necessary? That's kind of a judgement call, but I would say it's certainly needed when an edge has sustained visible damage - chipping, serious impaction, etc. that can't easily be burnished out, or removed readily with your finest finish abrasive.

Sometimes, too, an edge that hasn't been sharpened for some time will become weakened simply from work and corrosion. You know this has happened when your knife can be restored to keen sharpness with little effort (a few passes on fine media or steeling) but doesn't hold an edge like it used to. When that happens, a full sharpening is called for.

I've also come to believe that most production knives will benefit from a full sharpening when you first get them. This is due to the fact that factory edges often get overheated, sometimes even being shipped with visible discoloration of the steel, and the edge will be too soft or weak to hold up. This process is sometimes called "scrubbing in," with the idea being to get down to good, sound steel. Also, many factory edges will be uneven or incorrectly profiled for your needs, and so a full sharpening serves multiple purposes.

Having said all that, I'm not sure it's absolutely imperative to raise a burr every single time you do a full sharpening. A lot depends on your technique, the blade steel itself, sharpening media being used, and probably other factors. But like I said, it's good practice, because steel that's been weakened from work/stress or corrosion won't form a good burr. So when you're able to raise a good, crisp burr, it's a good indication you've removed any weak/burnt/corroded steel, and your knife will now be able to take a good, durable edge.

Hope that helps, Dave.

Dave
 
ColoradoDave- Thanks for a great answer to my question. Now, I will have to digest everything you've said, examine my edges carefully, and look for the things you point ot. Thanks again..
 
Thanks, averageguy and divebuddy. <blush> Give credit to Cliff, Joe, Jeff, and many others here on BFC from whom I've learned so much.

Dave
 
ColoradoDave:

Did you get my pm reply? It came back undeliverable after three days the first time [ I responded the same day you pm'ed me ], and have sent off a second response once I recieved notice it was undeliverable for some reason.

Just wanted to check with you.

Brownie
 
Brownie - yes, I received your reply, and sincerely apologize for not having acknowledged it yet. Will get back to you today (barring anything calamitous.)

Dave
 
No problem Dave, just wanted to make sure as the first one never made it for some reason.

TTYL

Brownie
 
divebuddydave said:
When sharpening a new or reasonably sharp knife, do you have to get a burr again? At what point do you know it is time to get a burr or whether it is just OK to "touch it up"?
Click to expand...
I don't raise a burr when "touching up". For a quick touchup, I just use the Spyderco Sharpmaker on the corners. By using just the corners it acts like a steel, realigning the edge and with the white stones, removes minimal knife steel. Best of both worlds. Even with a full sharpening on bench stones (burr raise), I will steel the edge first with a smooth butchers steel or fine cearamic rod. If I see nicks or bright spots when looking at the edge with a bright light after a touch up (bout 5 to 10 light strokes per side), then it's time for me to raise a burr.
 
I feel that everyone has contributed great stuff here, but I think they have left out the "other" missing link between touchups/steeling.

Stroping! It is so easy and effective. This is the procedure for me:
1. Be wearing a pair of jeans

2. Bend you leg and make the jeans go tight around your leg

3. Lay blade on upper leg and using a consistant angle drag it edge trailing to you

4. Then reverse side and drag edge trailing away from you

5. Repeat a few times and then test the edge; Should be razor sharp again

If that doesn't work then it is time for a touch up on the Spyderco Sharpmaker.... And if that doesn't get it ultra sharp it's time for the full sharpening.
-Kevin
 
I am one of the few people who don't like to raise a burr for touch ups (when you rebuild an edge it is a different story though). Instead I like to do alternating strokes, no matter if I am on the sharpmaker or on stones. On the Sharpmaker its easy, on a fine stone I do at most 10 strokes on one side, then 10 strokes on the other, then 5-5, 3-3, 2-2, 1-1, which essentially avoids a burr, because you remove it before it can really build. Gives a much better (cleaner) edge with less work. All that changes, though, if I am sharpening a chisel ground blade.

Duh :footinmou, scrolled down to fast and didn't see the post by ColoradoDave. Essentially, completely agree with him.

The most helpful visualization I found, is to take two wedges of wood with different angles (one shallow the other one substantially larger) which exactly doesn't matter, and flatten both long sides on sandpaper of different grid. You can essentially see all that is going on while sharpening in "fast forward" and magnification, and you can ask yourself, how you would be able to put the finest edge on this wedge of wood. It is a real hands one experience which taught me a lot.
 
I agree with stropping for light touch ups. Altho I use a leather strop with the lee valley green compound myself.
 
spyken said:
I agree with stropping for light touch ups. Altho I use a leather strop with the lee valley green compound myself.
Click to expand...

I think you raise something that I overlooked, and thats that with wear resistant steels you need to use that green compound for maximum effect. I usually don't EDC high-end steels. For less wear resistant steels like Aus6, 420hc,440C, aus8, etc., The jean strop does great.
-Kevin
 
Morgoth412 said:
I feel that everyone has contributed great stuff here, but I think they have left out the "other" missing link between touchups/steeling.

Stroping! It is so easy and effective. This is the procedure for me:
1. Be wearing a pair of jeans

2. Bend you leg and make the jeans go tight around your leg

3. Lay blade on upper leg and using a consistant angle drag it edge trailing to you

4. Then reverse side and drag edge trailing away from you

5. Repeat a few times and then test the edge; Should be razor sharp again

If that doesn't work then it is time for a touch up on the Spyderco Sharpmaker.... And if that doesn't get it ultra sharp it's time for the full sharpening.
-Kevin
Click to expand...

lol I thought I was the only one who did that!
 
I love these sharpening threads. I won't give any sharpening technique advice per say but what I will say is to listen to what everyone says. Absorb and try it all. At some point what you will develop is a technique or combination of techniques that work for you. When you can get edges that satisfy your needs then you will have developed your *own* style.

At some point you will want to take that style to the next level and get even better edges. At this point your style will become an art.

Sharpening as "artistic development" is both practical and personally satisfying. It cleanses the soul.
 
Well, I thought I was nuts about sharpening. Then I tuned in to the forum on the Shaptonstones.com page, where only woodworker hang out. Gave me a totally new perspective. They call shaving sharp if the edge catches hair a 1/4 in above the skin, and really sharp they call, when you then can pull up the blade and split the hair lengthwise :eek: !!! I am still working on an 1/8 over the skin and that includes stropping. I should mention though that these woodworking people would call the sharpmaker whites "medium grid" :rolleyes: .
 
Thank you all for the excellent advice and guidelines. This is all such good information. I am very new to the sharpening aspect of this hobby and have a lot of work to do before I am really proficient.-Divebuddydave
 
HoB - if you've never tried a Ron Hock plane blade (or similar) you really should. A2 takes an absolutely spooky-sharp edge easier than any other steel I've ever seen, and at ~62 Rc performs extremely well.

Dave
 
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