Sharpening FAQ

I use the Apex. It can make any edge razor sharp once you master it.
Recurves and daggers do take a LOT of practice. Hardest to master is dagger with very hard steel.
 
I've been playing around with stropping lately and have learned a few things.

Stropping is quick and effective way to finish off a decent sharpening job when you're sharpening freehand. It's difficult to maintain the perfect angle to the stone to get a polished edge just with stones when you're free-handing, but if you can get a decent edge on a knife then you can polish the edge with a strop (and proper technique) and get a good result. I'm not saying it duplicates what you can achieve with a sharpening system that rigorously maintains the blade angle during the entire sharpening process, but you can get a very nice polished edge and much improve the overall sharpness of the blade.

Making your own strop and charging it with a stropping compound.

A metal polish (I'm using Flitz) on leather (smooth or rough side--I'm using mostly smooth side) or on cardboard (like a notepad backer--not box material) makes a pretty good strop. It doesn't have a lot of cutting power, but it does a nice job of putting a polished edge on the knife.

If you're going to use a liquid polish on cardboard, get a nice, thin, even coating on it with your finger and then let it dry completely before using it. Otherwise the cardboard will have a tendency to come apart very quickly. You can easily recharge a cardboard strop with a liquid polish using the same method you initially charged it with. The cardboard will eventually start breaking down--it's disposable after all.

Flexcut Gold is a much more aggressive stropping compound that can be used on cardboard or rough side leather. In fact, when freshly applied, it actually cuts more than it polishes. You can easily see the abrasion striations it creates if you use it on an already polished edge.

Flexcut is harder to apply to the strop (they say it's like a crayon, but it's more like a really hard chalk), and if you use it on cardboard, it's even more difficult to reapply once it's stopped cutting/polishing. If you're going to use it with cardboard you need to figure that once you've applied it, then you use it until it's not cutting like you want it to and discard it. Trying to reapply it over an area of cardboard that's already been used is not worth the trouble. You might be able to clean the used area with a white plastic eraser and then reapply the Flexcut after it's clean, but I think that's more trouble than it's worth. Fortunately cardboard is usually free if you just keep your eyes open for suitable scraps.

Soft/compressible/flexible strops vs hard strops.

Leather and cloth strops tend to be soft/compressible/flexible. If you're going to use a strop in this class, you need to pay attention to how much pressure you're applying to the blade. If you push hard, you can actually defeat the purpose. What happens in this case is that the strop material sort of "rebounds" after the blade passes over it and as it rebounds, it swipes across the cutting edge and dulls it. Don't press hard when you're using a soft/compressible/flexible strop. The nice thing about compressible strops is that you can be a little sloppier with your edge angle to the strop and still get a decent result. The compressibility molds to the blade which means you don't have to get the angle exactly right.

If you're using a hard strop, like notepad backer cardboard, then as long as you are reasonably careful with your stropping angle (angle of the blade to the strop) then you can press harder. The material won't rebound and therefore you don't have to worry about it dulling the edge. Just be aware that the harder you press on a cardboard strop, the faster it will wear out. I'm not saying you SHOULD press hard, just that you can get away with a little more pressure using a hard strop.
 
Get a block of green compound to charge a belt or strop. If you know a jeweler you might get your strop charged by them since it will last about forever for the average person. If you have a belt grinder a leather belt loaded with green compound will put a frightening edge on a blade.
 
I'll give it a shot. What brand of compound do you recommend? I haven't been able to verify that "green compound" is the same from every maker...
 
Some updates. I've tried some green compound and it seems to work fine.

I also found that you can use a drop or two of rubbing alcohol on the really hard bars of polishing compound to dissolve/soften a little bit of one end to make it much easier to apply to a leather or cardboard strop. Otherwise I find that some of it can be difficult to apply--you have to press hard enough that you can damage a cardboard strop if you're not careful.

I bought two types of green compound, one by a company named Enkay and the other by a company named Formax. The Formax is easier to apply to the strop. It's softer and goes on with less effort compared to the other compound bars I've experimented with. I can't tell any difference in the way the Enkay vs. the Formax compounds actually work on the blade.

The only negative thing I've noticed with the green compound is that it is not at all aggressive. Unlike the Flexcut Gold, it takes some work before you'll start to see any effects at all on the blade edge. In fact, I think it is even less aggressive than using Flitz as a stropping compound. It does put a very fine edge on the blade if you are persistent/patient but personally, I don't think that there's any significant benefit in the quality of the blade over what is achievable with the Flexcut Gold. Certainly nothing that would make the extra effort/time expended worthwhile.

That is based on stropping by hand. I don't have a belt grinder to test the stropping compound as hso describes.
 
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The fineness of the compound depends on what you want to do with it. The formax stuff isn't even that fine. It contains aluminum oxide particles much larger than fine chrome-ox. Even pure chrome-ox has a huge effect on an edge, compared to a naked strop. But since Formax is too fine for your liking, you maybe don't have the need to try the pure stuff.
 
The fineness of the compound depends on what you want to do with it.
True. I'm looking to stropping as a way to put the finishing touches on a knife that's already been sharpened properly. If it takes too long or requires too much effort, then there are other ways I can do it faster, although they do require more skill.

A few passes on a Flexcut impregnated strop really puts a nice finished edge on a blade that's already sharp and only requires a minute or two of time. To get the same effect with the Formax/Enkay green compound takes several times longer.
 
I make knives professionally. Here is the machine I dedicated to only do sharpening in my shop. image_21866.jpg $59 at harbor freight. The only time I would not recommend this machine is to someone who does not understand "correct angle". 1"X30" leather belts are available for about $20 online, called "surgi-sharp". Abrasive belts usually run less than $2.00. Just with this little bugger you can make a butter knife shaving sharp in under 2 mins. I use a black bar compound and the resulting edge can split a hair lengthwise if you care to get it that sharp.
 
Steve Bottorff (the author of “Sharpening Made Easy” is a good acquaintance of mine. Just to let you all know, he has recently retired from the knife sharpening field except for a few friends and long time customers.

Those of us in the sharpening fraternity wish him long happiness playing his bass flute. Truly a one of a kind guy and willing to share his knowledge with others.

Kevin
 
I've found the Ida-Hone (red and white) ceramic rods work quite well for some knives.
For our Wusthof kitchen knives; their sharpening steel does quite well. And with others, the Arkansas soft and hard stones do the trick.
IMO, it depends on what kind of edge one seeks.
 
I suggest the Wicked Edge sharpening systems. They are not cheap although they are less than a few of the ones shown in this thread. I have used many different sharpeners and stones over the 50 years that I have been sharpening my knives. The Wicked Edge is capable of setting the angle precisely (within a fraction of a degree) for both sides of the blade and maintaining it I have stones, ceramics and leather strops for it that start at 100 grit and go up to +2000 grit which makes an edge with a mirror polish and cuts like a laser.
 
For final honing I have mostly switched to diamond coated steel plates.

Never an issue with stone hardness vs the metal you are working with.
After use just wash them off and allow to dry.
A little oil will make sure rust does not start.
 
I switched to DMT diamonds a while ago. I like them enough they have become my primary system. I go through 3-4 sets a year. Other guys buy my worn out plates!

Kevin
 
One thing that hasn't been mentioned is that there is not just one grit standard.

You can use grit numbers to compare one company's products against each other, but when you compare one company's products to another based on grit number alone, you may not be getting a very accurate comparison.
 
One thing that hasn't been mentioned is that there is not just one grit standard.

You can use grit numbers to compare one company's products against each other, but when you compare one company's products to another based on grit number alone, you may not be getting a very accurate comparison.

Absolutely correct! It isn’t until you get into microns that there is an established standard.

Kevin
 
Here's a pretty good video on stropping.

One thing he leaves out (probably because he's focusing primarily on woodworking tools) is that the really abrasion resistant (great edge-holding) knife "super steels" can be frustrating to strop with normal stropping compounds because the carbides in them can be harder than the abrasive in the stropping compound. It doesn't mean you can't strop them with normal compounds, but your progress may be slow. I find that a few strokes is good enough to finish off a low alloy stainless or carbon steel blade but that I may have to really spend some time stropping if the knife steel is one of the "super steels".

If you want to strop supersteels with rapid results, it might be worth looking into a diamond paste or spray as opposed to using a more traditional stropping compound. One other nice thing about the diamond pastes/sprays is that they tend to be marketed with the micron size of the abrasive particles which eliminates the issue of traditional stropping compounds that use ambiguous grit designations or maybe don't provide any information at all in terms of abrasive particle size.

He dismisses diamond sprays and pastes, due to their cost, but for some knife stropping applications, they could be a good option.
 

For the price of one knife.
I had the industrial version of that. It carried 2.5” x 10” stones. They work, BUT, your hand is sliding over the sharp edge. Let something leak down a little and get the band aids out.

My current system,



IMG_8055.jpeg
Using the same DMT stones but my hands hold and control the blades.

Kevin

To have the extra cash to buy a knife sharpener is a great place to be in in life
My wife just married one!

Kevin
 
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