How do I keep from messing up at the bench grinder?

L

lerner

Joined
Sep 1, 2008
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When I try to rebevel/reprofile a blade on a bench grinder, the blade walks or chatters all across the wheel.
I cant see whats making contact since its on the other side.

If I hold the knife horizontally at the top at 12 o'clock (like using the paper wheels),
how do you maintain a constant sharpening angle to the wheel?

I'm about to recieve a couple nickel-plated daggers
and I'm worried about freehanding with powertools.
My hands never were that steady.
 
Sounds like your wheel is either;
1)Rotating too fast. 2)Out of balance (not round and or not concentric from left to right.

Wheel speed may or may not be adjustable depending on equipment.

Wheels can be dressed to make them more even (flat across & without highs & lows). There is a tool specific to this purpose.

Place an object like a flat blade screwdriver against a tool rest so that it barely touches the wheel & rotate the wheel by hand and slowly move across the wheel to check the wheel condition to see if/how it needs dressing.

If the wheel is spinning fast (greater than a few hundred or so rpm), there is a high probability you may damage the blade steel using this type of equipment (i.e. ruining the steels final temper at the blade edge).

Hopefully something here that helps.
Regards,
 
Last edited:
Rule of thumb- bench grinders should NEVER be used on knives. All you will accomplish is ruining the blade and the heat treat.
 
Bill DeShivs said:
Rule of thumb- bench grinders should NEVER be used on knives. All you will accomplish is ruining the blade and the heat treat.
Click to expand...
+1 on that.

Perhaps however the overall project for the OP is not sensitive to this though, and more of an exercise in playing around with existing tools and or to make wall art ... we all learn best by doing and experiencing. Some lessons more expensive than others.

Regards,
 
I recently watched a video that addressed this. Your grinder wheel may not round. If it is not PERFECTLY round, then it can cause the tool to chatter.

BUT, I still agree with Mr. Deshivs. I wouldn't sharpen a knife on a standard bench grinder. Even if the wheels are true, I bet the stock wheels are too coarse. They make half speed bench grinders with finer wheelsfor this kind of thing. A Rikon Slow Speed Grinder will set you back about $100.
 
So how do I rebevel a dagger?

Freehanding, even on a DMT diamond extra coarse, takes forever and I cant maintain a constant angle.
 
Use a Belt grinder with a reversible/ variable speed Controller. I use a Norm Coote grinder/ Leeson motor/ KBDA-27D rig I assembled myself

http://cootebeltgrinder.com/index.html

http://www.electricmotorwholesale.com/9543-KBDA-27D/

http://www.electricmotorwholesale.com/LEESON-113026/

DSC_0004.JPG
 
lerner said:
So how do I rebevel a dagger?

Freehanding, even on a DMT diamond extra coarse, takes forever and I cant maintain a constant angle.
Click to expand...

Sounds like you have a technique issue that you need to address before using a coarse stone let alone a bench grinder.

Bill and I don't agree often but I +1000 his comment.
 
DMT Aligner, Gatco, and Lansky clamp systems are out.
The knife in question has a nickel finish I dont want a clamp to mar.
Too bad because I like my Lansky.
Plus, the coarsest Lansky diamond is too slow for rebeveling.

I just wanted to do this the way a profesional sharpener would have.
How would that be (to rebevel an expensive dagger without scratching the finish)?
 
You began asking about using a bench grinder (cringe, but we all have to learn from something :-)

Now you just stated they are "expensive". I do not believe you mentioned if the nickel coating is in the area where you are looking to grind (significant consideration due to associated cost of knife disassembly and nickel re-coating process.
I had originally assumed that being nickel chrome coated that these knives were wall-hangers and perhaps just a fun hobby project. Very few "user knives" are chrome plated (nickel coating is effectively a chroming process).

It sounds to me, there may be a few more considerations related to your project, that you may seriously want to review. Also, maybe better left to someone proficient in blade grinding than a DYI type project.

No disrespect meant. Maybe a picture of the knife would go a long ways done the road of solutions & options ... :-)

Regards,
 
lerner said:
DMT Aligner, Gatco, and Lansky clamp systems are out.
The knife in question has a nickel finish I dont want a clamp to mar.
Too bad because I like my Lansky.
Plus, the coarsest Lansky diamond is too slow for rebeveling.

I just wanted to do this the way a profesional sharpener would have.
How would that be (to rebevel an expensive dagger without scratching the finish)?
Click to expand...

It's not a skill I can pass along through text. It takes years of practice to be proficient and for some the skill will never reach a professional level.

Professionals such as myself would recommend you stay away from coarse stones and machines until you become proficient with sharpening. If you need bevels set and cannot do it by hand then I would recommend sending it to a professional such as myself to correct the geometry which will allow you to maintain it with finer stones.
 
I think that attempting to rebevel a dagger with your
present skill set may be biting off more than you can
chew. No disrespect meant. Daggers can be a real b***h.

A bench grinder really isn't the appropriate tool for reshaping
and sharpening knives. Way too easy to overheat the steel.

My dad had a good way to teach us how to use tools. Learn
the process by hand and when you know what you're doing,
then move on to power tools. Better results and fewer injuries
to both the work and yourself,

Bill
 
These have all been excellent answers. Thanks for the input.
I'll have to take time to think.
The Fairbairn Sykes is still in the mail anyway.
 
lerner said:
These have all been excellent answers. Thanks for the input.
I'll have to take time to think.
The Fairbairn Sykes is still in the mail anyway.
Click to expand...

Something to consider,

The dagger you have ordered is not designed to be a sharp object, it's designed to kill by being real pokey. They also have thick geometries that can make it near impossible to put a good edge on them.

It's also been found that if made very sharp they stick in objects like bone. So, I wouldn't worry too much about putting the edge of excalibur on a dagger that probably won't get very sharp anyway.
 
+1 on JasonB comments.

I have two knives from WWII that were hand carried home from war (still as they came from the battle field) and neither has a "cutting edge". They are/where thrusting weapons.

I believe the only way a F-S knife would have had a cutting edge would be if someone altered the knife post production (potentially significantly devaluing the knife, if that is of any matter to your consideration).

Also, a "double-edge sharpened" knife where I live really steps up the illegality issue from a typical "dagger" designation.
 
Like others have said it could be your wheels are out of round. I have also experienced blade chatter when I'm moving the blade too slowly across the wheels. It has taken me years of practice on cardboard wheels to become proficient but there are still some knives I won't sharpen on them for one reason or another. Thin blades burn really fast and the 220 grit I use doesn't like certain blade coatings very well.
 
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