Grinding the final cutting edge

S

sedergraphics

Joined
Aug 25, 2004
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My first knife has gone very smooth up until now. Just got my 1st blade back from HT and was trying to grind the final cutting edge and things went very wront. The grind looked terrible.

Do most of you use some type of jig? Free hand? Any suggestions?



Kraig
www.sedergraphics.com
 
The cutting edge should be the very last thing you do to the knife, before shipping it out. You will be more likely to keep all your fingers, and toes that way.;)

Blade finish, handle, and sheath should all be done before that.

That said, I really need more info to go on. What type of grinder are you using?
What setup on that grinder are you using, and what belts(grit, etc.) are you using?
And, how are you grinding the cutting edge, or do you just mean the blade bevel?
 
I agree with mike, more details please!

are you keeping a constant preasure and angle?
maby the temper was to soft/hard.
is your grinder moving or bouncing?

lots of factors
I have the same problems some times :mad:
 
I was using a 1" Delta belt sander with 80 grit. Wasn't vibrating, or moving too much... um but I probably was. My problem is that I wasn't holding the angle exactly the same on multiple pases.

I actually fixed my mess-ups and finished with a sharpening stone. I'll tape the blade up before doing the bolster and handles. I should probably keep the fingers for future knives (thanks for the tip). Next time I'll save final grind till last.

I think that I will hold off on the final grinds with a grinder until I get my KMG in a month or two. Then I plan to practice on a whole lot of scrap metal.

When I get my KMG, do you suggest a jig? Or should I practice free hand? And do you do one pass, or multiple passes? Face up like the bevels?

This first knife has really been a great learning experiance. So far I've been able to correct or hide all the boo-boos to the knife. But I can't hide all the cuts and bandaids on my hands.

Thanks for your help. Without you guys I wouldn't have learned near as much this quick, even with the books I've been reading.


Kraig
www.sedergraphics.com
 
When setting the final edge be VERY CAUTIOUS about grinding edge up.The knife will grab,flip downward,and take a piece of your fingers with it.I form the final bevel on a new 220 grit belt - edge down- and finish on stones.You should not need to remove so much metal that you need an 80 grit belt.
 
I grind my bevels edge up, but my sharpening is done edge down(assuming that the belt direction is over the top, and down). Like was stated above, sharpening edge up can lead to problems, for you, and the knife.:eek: ;)


It's pretty easy to set the angle that way too, as tou can better judge by the back of the blade.

I would advise against jigs. Learn to grind freehand and you never limit yourself in grinding style, and you will be the better maker for it.
 
I put a reversing switch on the Burr King and reverse the belt and sharpen edge up so I can see what I am doing. I did this after finding our the hard way what can happen but was lucky I still have all my parts. Gib
 
sedergraphics said:
Thanks for the good info. I will definately practice free hand. Is the grind normally, or optimally done in one pass?


Kraig
Click to expand...

No! If you're talking about sharpening, it varies with the grit belts you use, and the amount you have to remove from each side. It can take many passes.

Just be careful not to overheat it in the sharpening stage. It doesn't take much grinding on the thin edge with a fine grain belt to ruin the temper.

If you are talking about the blade bevels, we all wish.:eek: ;) :D

That can take many passes. Only make a pass or two, then repeat on the other side. That will lessen your chances of creating stresses in the blade steel that can lead to warping in heat treat.
 
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