Sharpening System Advise Wanted

Never Dull

Never Dull

Joined
Feb 20, 2011
Messages
384
I am a Wicked Edge user and I sharpened knives for friends at a market. Now their is a need for sharpening and I am thinking of a weekend biz doing this. What is a good system to do a bigger volume as the WE is too time consuming? I checked out the Tormek site and that seems ok. Hope you can help me with suggestions and input. Thanks
 
Thanks for the suggestion, what makes the paper wheel better than say a belt sander and the different grit/stropping belts? Sorry to be such a noob but I want to learn.
 
Never Dull said:
Thanks for the suggestion, what makes the paper wheel better than say a belt sander and the different grit/stropping belts? Sorry to be such a noob but I want to learn.
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A large belt sander(say, 1"x30" or 1"x42") can run the risk of ruining the temper on knives due to heat, though that depends on individual ham-handedness and skill. My only real pet peeves about the paper wheels is that it is essentially a straight edge sharpener on steroids, and I've found that the slightest inconsistency in holding the blade at an exact angle will result in your edge looking like it was ground at 3 different angles. As someone who has shaky hands second only to a junkie, I like using my mini belt sander(the Work Sharp Knife & Tool Sharpener) because it's much more forgiving of imprecise angles.

Admittedly that system doesn't do too well without aftermarket belts, but I find it to be more "flexible" if you'll excuse the pun. Though the flexible belt would also mean that any edge put on with it is convex. Still, I feel it offers a wider range of options depending on the belts you get. My experience with the paper wheels tell me that the achilles heel of the system is high carbide steels like ZDP-189, S90V, etc. Metal removal isn't nearly fast enough to quickly reprofile an edge with such steels. Though admittedly the average joe won't be using such steels, and the manual recommends no more than 20 minutes of use per hour, so I wouldn't be able to sharpen hundreds of knives in one sitting. Though I did happen to sharpen a nice 26" katana with it, as well as grind a new edge on a badly damaged machete.
 
I do farmers markets occasionally and you would not believe the things people bring in. Knives, scissors, pruners, axes and hatchets. I even had one guy bring in an antique russian ice saw he wanted refurbished. So far I haven't found any one tool that will do them all. So I use three. The 2"x42" belt sander for large thick blades. (ax, hatchets, machetes) or if severe reprofiling is needed. and the paper wheels for pocket/kitchen knives. I have my tormek in the van for the occasional woodworking tool. I would say that 99% of your needs would be met with the wheels and sander.
Good Luck!
 
The paper wheels are excellent. go for it. if it is pocket knives, then the wheels will handle it, but i can see the advantage to the belt sander. see mongolguys post. he is correct. if you do get the belt sander, be sure to have a bucket of water standing by to dip the blades in every couple of passes.
 
Thanks for all the suggestions, I was that I couldnt get away with a single system. Will research the paper wheels more. The tormek is a bit pricey for a farmers market I think.
 
Yeah, the tormek I got when I was looking to go full time sharpening. Great for woodworking tools! Problem is most pro craftsmen buy one and sharpen their own tools. There are cheaper options from JET and Grizzly that will use the same jigs (I think)
I like using the belt grinder to thin the blade because like Noctis3880 I have problems holding a perfect angle on the wheels if I have to make multiple passes. Not a problem with most kitchen/pocket knives. But when I start doing thicker "survival" knives I get the multi angle look. I'm a gadget-aholic so I have the Edgepro and Wicked Edge systems too and I really like the perfect bevels you can get with them. But I don't think they are practical for turnaround time.
 
Two systems should do what you need. For axes and choppers you might appreciate the durability of a good convex edge on such tools. The paper wheels should do everything you want it to do for other people's knives. The Wicked Edge and Edge Pro systems are more for putting a picture perfect mirror edge on blades, something again the average Joe isn't too concerned with.

If I were doing sharpening en masse, a fast and sharp edge would be #1 on the list of priorities. Sure wish I was in your position though. Sharpening edged tools all day sounds like my cup of tea:D.
 
a paper wheel system is less likely to screw up a knife in my opinoin if you dont really know what your doing or have little experience with it. At least thats what I think.

Its fast, its cheap, it works, it give you an amazing edge. what else could you want?
 
eccvets said:
a paper wheel system is less likely to screw up a knife in my opinoin if you dont really know what your doing or have little experience with it. At least thats what I think.

Its fast, its cheap, it works, it give you an amazing edge. what else could you want?
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A professional sharpener in the neighborhood :)

BTW, I completely disagree with the above statement and imo you should not say these kind of things.

Any machine will destroy a knife much quicker than hand sharpening when you do not have any experience with them.
Let that sink in and read on.

Here's why, pay close attention, think about it and stop propagating the above statement

The whole reason why paper wheels are quicker are because they remove metal faster than other methods because there are spinning wheels at a lot of rpm, maybe 1700?

say that a wheel has a sharpening surface of (2*PI*radius is circumference) 2*pi*r(say 2 inch) is about 2*3.14*2 is about 12 (I'm rounding off to a lower value) inch of sharpening surface per turn of the wheel.
1700 rpm or just say for arguments sake 500 rpm (which is way low) * 12 is 6000 inch of sharpening surface per minute. in 0.1 second you're moving your knife over about 6000/10/60 is 10 inch of sharpening medium and I bet that in 0.1 second you can hardly do only 1 inch of a knife, but just say for arguments sake that you're the worlds best sharpener and can control that amount.

SO each inch of your knife is sharpened over at least 10 inch of sharpening medium in 0.1 second.


Take into account that I'm using very low figures for the diameter of the paper wheel and the rpm and the reaction time of your sharpening method.

more realistic values would be imo:
2*PI*3.5 = 22
22 inch * 1500 rpm = 33000 inches per minute of sharpening medium
in 0.2 seconds your sharpen an inch of the edge so that inch of the travels over (33000 * 0.2)/60 = 110 inches of sharpening medium.

And you are saying that hand sharpening, which is done with at most a 10 inch benchstone, will destroy an edge more easily if you don't have any experience?

LOL!



I believe RIchard J knows his stuff. I don't know you, you are probably very knowledgeable in a lot of fields, but the above statement probably means not in the field of paper wheels.
Richard J himself says you can get good edges in under a minute.
say that you only have your knife on the wheels for 10 seconds of that minute.
that's a whopping 3300 inches of sharpening medium.
Also say that we're talking about an average large folder of 5 inches. that's 10 inches of edge in total.
That is still 330 inches of sharpening medium per inch of the knife
in 10 seconds....

now THAT will destroy a nice knife pretty quickly...
 
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I agree, automation speeds up sharpening and dulling (or worse, the wrong profile for a given steel or over-temping the steel). but if the OP is really looking to turn profit and quality, then it's just time to learn automation, it's not quantum physics :)

err, one other thing: while i do not sharpen professionally, i would recommend this: do not sharpen a knife that you cannot afford to replace, there is always that chance that something could go horribly pear-shaped and then some guy's superextremefancycustom knife is a useless pry-bar.
 
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My vote would go for a Kalamazoo 1" belt grinder (Model 1SM if my memory serves) and a decent assortment of belts. The belt grinder with a simple belt change (about ten seconds) will let you do anything from re-profiling a broken tip to mirror-polishing an edge, and do so all day long. I'm still quite new with mine, but the learning curve is quite short. The heating issue isn't a particularly big deal, I keep a pan of water beside my belt, and if I can feel any heat in the edge with my fingertips as soon as it comes off the belt, I give it a dip. I haven't toasted a knife yet. I'd be much more worried about the grinder, the surface feet per minute with a wheel are a LOT higher, and you don't have the choice of grits to change how the material comes off.
 
Komitadjie said:
My vote would go for a Kalamazoo 1" belt grinder (Model 1SM if my memory serves) and a decent assortment of belts. The belt grinder with a simple belt change (about ten seconds) will let you do anything from re-profiling a broken tip to mirror-polishing an edge, and do so all day long. I'm still quite new with mine, but the learning curve is quite short. The heating issue isn't a particularly big deal, I keep a pan of water beside my belt, and if I can feel any heat in the edge with my fingertips as soon as it comes off the belt, I give it a dip. I haven't toasted a knife yet. I'd be much more worried about the grinder, the surface feet per minute with a wheel are a LOT higher, and you don't have the choice of grits to change how the material comes off.
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Thanks for the insight. I do have a 30" belt sander and use it for stropping with a leather belt. For sharpening wouldnt it only produce a convex edge? Many folders prefer a straight edge. Also, unless you are re profileing the edge would you be removing so much material as to over heat the blade for just sharpening it to a wire edge?
 
It will produce a convex edge if you use it in the slack belt portion above the platen, or a straight bevel if you use it against the platen itself. Heating is more of a problem when you are using the platen than when you are using the slack. For general sharpening on most knives that aren't particularly badly beat up, my first belt is generally a 400-grit. A couple light passes will bring up a wire quite nicely if the edge just needs a bit of touch-up. In general, the finer the grit, the more heat is generated per amount of metal removed. Hence, if you need to seriously re-profile, switch to a coarser belt and don't just make a bunch more passes with a fine one. If you have ANY thought that you might be heating the edge too much, just have a glass of water handy. A quick dip between each couple of passes will take any possibility of overheating away. The heating risk is greatest at the tip, since the thermal mass is a lot smaller than the rest of the blade. I'd suggest that since you already have a sander, just pick up a couple of belts and a cheap knife to give it a try! A 120 (for serious rework and tip-shaping) a 240 (for starting out on a knife that needs more than just a light touch-up) and 400 belt, followed by compound on leather will put a VERY workable edge on a knife in a very great hurry. You can spend as much or as little as you like on belts, I've seen them range from about $.80 a belt, to almost $8 a belt depending on what you're after. You can easily get belts down to 5 microns, and even smaller from 3M's Trizact line. Remember, a belt will tend to cut a tad finer than a stone for the same grit size.

Honestly, the heating risk is not one that I'd consider particularly severe, I haven't overheated a knife yet. It will be a tad trickier with your 30", since I would suspect it's belt speed is considerably quicker than my Kaly's. Just make a pass or two, then dip it to avoid any chance of damage. In general, if you can immediately hold the edge in your fingers when it comes off the belt, you're not heating it too much. The average human will drop something at about 130F, and most steels don't enter their tempering phase until in the 400s.
 
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Zyhano: the wheels are fast but RPM is per minute not second so your calculations are off by at least a factor of 60.


Noctis: how is a big belt sander any more dangerous than a little belt sander? I'm not sure its safe to say a big sander is dangerous to the heat treat but a small one is fine.


Any powered system can over heat steel depending on the speed, grit, pressure, and thickness of the steel. But it doesn't take much practice to learn how the system behaves and having a water bucket handy helps cool things down. With practice they probably all work great but I would imagine a belt sander would be quickest if doing tons of knives. Not sure you would have tons of knives at a flea market so I would research and go with what you like best. The wheels have some downsides but you don't have to change out belts often if you want a mirror finish.
 
Good input Komitadjie!! I will try that out using the platen and see if I can maintain a straight bevel. I know no one system is good for everything. and the ability to take advantage of different techniques is a plus. Thanks to everyone for their suggestions ( I do want to try those paper wheels if this gets busy). Cheers all and I wish I was at Blade!!
 
FlaMtnBkr said:
Zyhano: the wheels are fast but RPM is per minute not second so your calculations are off by at least a factor of 60.
.
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Yes, thanks for pointing that out. I was a bit off target because of the paperwheel mumbo jumbo...
I'll correct the post. Still a lot of surface though :)
 
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