Dull Blade that won't take an edge

ericnpeterson said:
No, I'm not jumping back and forth. I'm finding an angle and a stone surface and stick to it for an hour at a time.
The other day, one hour straight on coarse diamond, then an hour on fine side.... at 25 degrees, then ripped paper with my knife.
I'm not doing 25 degrees for 8 strokes then 10 strokes at 35 etc... I pick and stick to one thing.
Click to expand...

Well, next time, do this instead :D
Do 20 degrees, coarse stone only, grind one side for a full minute, scrubbing passes, then check for burr,
don't switch sides until you raise a giant floppy burr you can see from space
this is the fallback technique when you just can't seem to get something sharp,
grind one side until giant burr


then switch sides and grind other side for one minute at 20 degrees, coarse stone only, scrubbing passes, and check for burr

when you raise a burr on the other side, move onto fine stone,
double the angle to 40 degrees
and do maximum two passes per side alternating with light force to cut off the burr
feel for burr again, and do two more alternating passes if you need to

you should be shaving sharp now
you can now do 5-10 alternating passes at 20 degrees or 25 degrees,
but do no more than 30 passes per side

You can see this guy do it on a smith's coarse bench diamond stone, although he uses too much force and wears out the stones how to sharpen a knife - Joe Calton

update:
you should keep force on diamonds under 1lb (450grams) or about half pound (225 grams)
for cutting off the burr keep it under 100 grams
 
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bucketstove said:
Well, next time, do this instead :D
Do 20 degrees, coarse stone only, grind one side for a full minute, scrubbing passes, then check for burr,
don't switch sides until you raise a giant floppy burr you can see from space
this is the fallback technique when you just can't seem to get something sharp,
grind one side until giant burr


then switch sides and grind other side for one minute at 20 degrees, coarse stone only, scrubbing passes, and check for burr

when you raise a burr on the other side, move onto fine stone,
(...)
Click to expand...

The burr's the key to everything. Bottom line, that's what needs to happen before attempting anything else. The one constant I've seen with Case's stainless is, it's easy to raise a burr on it (and sometimes difficult not to). If the burr never forms in spite of hours of grinding, that's the strongest indication that the angle isn't being held steady, which rounds off the edge; the burr can't form because the edge is too rounded and never gets thin enough to form it.


David
 
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Great news fellas,
All of your advice was accepted for sure.
I used my Smith Sharpening kit, the clamp holds it at proper angle, and then i just kept working at it with the coarse stone.
Finally got the required results, took it then to the fine stone (still using the clamp) and then finally polished it off with smooth stone.
I worked awhile on each stone, now my blade is surgical sharp (yippie!)
The knife needed alot of work, trouble was I wasn't working it enough at a fixed angle. (Many of you pointed out)
Thanks for everyone's help/advice.
"Nasa, we are achieving lift-off..."
 
Congrats!!!
That one is a huge step forward In experience gain, next time you face something similar you'll tackle it right away
Mateo
 
ericnpeterson said:
Great news fellas,
All of your advice was accepted for sure.
I used my Smith Sharpening kit, the clamp holds it at proper angle, and then i just kept working at it with the coarse stone.
Finally got the required results, took it then to the fine stone (still using the clamp) and then finally polished it off with smooth stone.
I worked awhile on each stone, now my blade is surgical sharp (yippie!)
The knife needed alot of work, trouble was I wasn't working it enough at a fixed angle. (Many of you pointed out)
Thanks for everyone's help/advice.
"Nasa, we are achieving lift-off..."
Click to expand...

Congratulations :) How many hours did you spend cutting stuff afterwards? Are you completely hairless now? :D
 
ericnpeterson said:
Great news fellas,
All of your advice was accepted for sure.
I used my Smith Sharpening kit, the clamp holds it at proper angle, and then i just kept working at it with the coarse stone.
Finally got the required results, took it then to the fine stone (still using the clamp) and then finally polished it off with smooth stone.
I worked awhile on each stone, now my blade is surgical sharp (yippie!)
The knife needed alot of work, trouble was I wasn't working it enough at a fixed angle. (Many of you pointed out)
Thanks for everyone's help/advice.
"Nasa, we are achieving lift-off..."
Click to expand...

:thumbup:
That's great news. Nice work. :)


David
 
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