problem sharpening chisel ground blade

SHOKR

SHOKR

Well-Known Member
For two days i have been working on only two kirdashis, for some reason im working really slow. But the main problem is sharpening. I sharpened chisel grind before. But this time i am unable do the sharpening right!
I must have gone back and for between 400g belt and the strop 20times for the two and one is aharpened, but not as good as i could get it and the other is not. The second was actually looking really bad i had to grind the bevel, and it looks even worse today

Anything im doing wrong?
At 0.4mm (aprox 0.017) i ground secondary bevel with 200g then went to 400g then strop (what i always do)

Everytime i check for burr before going to strop. What ends up happening is not all burr is removed, or i remove it well, but end up with blunt edge.
I tried strop on bevel side then flat, flat then bevel, only flat, tried all that with different angles... End up with blunt or 'saw' edge.

I spent two days on these... I couldve finished one or two large knives!!

20130521_210556.jpg


and end product (needs to be fixed of course)
%255BUNSET%255D.jpg


Thanks
 
Hello Shokr,
From your description of your "blunt or saw edge", Are you sure these were heat treated properly?

Put the teeth of a file over the edge of these and listen to hear it sing, If it doesn't sing or have a high pitch against a know piece of non Heat treated, same kind of steel than that is at least a starting place for the reason you can't get a edge on these little knives.

There are sets of files made for getting a approximate RC of heat treated steel.

Little blades like this would be fairly easy to heat treat yourself with a one brick forge set-up of say, 0-1 or 1084 carbon steels.

How this helps.

Laurence

www.rhinoknives.com
 
thanks a lot Laurence

according to the HTer these were tested to 58-60
but i just might try your way and see

thanks!
 
i checked with a file, the soft metal made a low tone noise. the hardened made a higher pitch one
 
Hmm.... I'd maybe try spending a little more time grinding on your bevel side. Looks like you actually have two different secondary bevels, and not actually a burr. Hard to tell from the pic.
 
hey Andrew

that photo is after quite a few sharpening attempts (and strop), so no burr but the edge is ugly, i ground the bevel again, TWICE!!
 
They're obviously garbage.

You should send them to me so that I can properly dispose of them. ;)

In all seriousness, I'm not sure what the issue is. I've sharpened knives before where they look sharp, and feel sharp, but won't pop hair or even cut paper all that well. A couple more passes on the belt grinder and buffer, and they're right where they should be.

All I can tell you is to try grinding the bad part off and trying one more time. Third time's the charm isn't it? ;)
 
Well, neither am i, the most recent conclusion is i left the edge too thick beforecsharpening, doesnt make sense to me but thatcmy final bet

And yes, there is burrcalong thecentire edgr, then strop, then it cuts nothing! So will check one final time. Problem is someone already asked for this one. So hopefully i can fix it

Thanks
 
SHOKR said:
i checked with a file, the soft metal made a low tone noise. the hardened made a higher pitch one
Click to expand...

Shokr,
If you aren't getting a high pitch of the teeth skating across the steel that they are NOT 58-60 RC.

Take them back to the heat treater and have him do them again. If the steel isn't at least a 53-55 you won't really be able to put a edge on them.

Simple carbon steels can be heat treated many times. Little blades like those you can do in your own one brick forge without to much hassle.

Laurence

www.rhinoknives.com
 
but i am getting i high pitch Laurence

will sharpen regular blades soon and see

thanks
 
Laurence, yeah thats wht i am betting on right now, and my last hope really

Andrew, Sverker 21 (D2)
 
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