Recommendation? New sharpening equipment???

[Jstanny88]

Ok guys let me start off by saying I am a bit of a beginner to knives/sharpening but I am really getting into it. I’ve been working at a pig slaughterhouse for the past year (gross lol but it’s good money, and it’s actually pretty fun). So I work with knives every day and have just recently started collecting some of my own. I’ve got a few automatics that I’m really digging. So the way my work sharpens our knives for us BLOWS ASS. When they bring them back I immediately have to hit it on my ceramic rod first and then my smooth butchers steel. We also have a grinder that we can use ourselves which works pretty good. It’s got a really abrasive wheel and then a polishing wheel on it, but man does this hog off metal like no other..not really worried about it though because I can get new knives fairly easy... but the grinder is also hard to get to because everyone always wants to use it... so I’m looking for something I can get for my home that I can maybe bring my knives home every night and sharpen. I say every night because we have victorinox, and they are rather soft steel.... chip and go dull easy. Right now At home I have a ken onion with the blade grinding attatchment... which is cool... and it works pretty good... but I’m not so sure it’s the best thing for using 3 knives everyday on it... and it severely convexes the edge, and I’m after more of a V grind. Ive used the BGA on my work knives a couple times but they always seem too “thick” to cut through the hogs. I’ve been looking at a couple options but I keep looking at maybe getting a buffer and some razor sharp edge making paper wheels... would this be a good option for me? Does the razor sharp system hog off enough metal where I could change the angle fairly quickly??? Cause the BGA is cool and everything but it takes me forever to change an angle from like 25 to 20 degrees.

One last question that you probably see all the time lol. I know all about raising a burr on one side and then moving to the other and then removing the burr..: my question is the sharpie method. If whatever I’m using is only removing sharpie from the edge and not the whole bevel do I need to lower my angle? Or can I just keep going until it’s all removed. Again if the sharpie is hitting only the top of the bevel and not the edge do I need to higher my angle or can I just keep going until it’s removed? That’s one of the things I’ve been struggling with.


Thanks guys!

Jesse

 

[bgentry]

You seem to have competing goals. On the one hand you say the WSKO BGA might be "too much" for working on blades every day. On the other, you say it takes too long to remove a lot of metal with that tool when you are changing angles.

Perhaps you need (at least) two systems: One for doing major work and one more oriented to touchups. A "real" 1x42" belt sander is something like 5x more powerful than the WSKO (in terms of abrasive surface per minute). This is a ballpark; I haven't done the calculation in a long time, but it's close-ish. So you can remove a LOT more metal faster with a real belt sander than with the WSKO.

You talked about your blades being "too thick" and being "overly convexed". I'm guessing, but it sounds like you are pressing too hard against the belt, causing a lot of flex, which makes the belt wrap around the blade. This might lead to an edge that's very convex and has a steeper angle than you intended. If you use lighter pressure, you should be able to produce approximately the angle you want and not "overly convex" the edge.

About sharpie marks and removal: When the sharpie only gets removed from the very bottom of the edge, it means that your holding angle is HIGHER than the bevel is currently set at. For example, you might be holding at 25 degrees, while the bevel was set at 20 degrees. In this case, lower your holding angle until the entire bevel is getting hit.

When sharpie only gets removed from the TOP of the bevel your holding angle is LOWER than the existing bevel angle. You have two choices: Raise your angle until the whole bevel is getting hit. Or keep going for a while until you change the existing bevel angle to your new bevel angle. For example, the blade might be set at 20 degrees, but your holding angle is 15 degrees. If you keep at it for long enough, you will grind in a 15 degree angle all the way to the cutting edge.

Speaking of edge angles, as a meat cutter, you will probably find that a lower edge angle works better. A lot of people will tell you that low edge angles (12 degrees, 10 degrees (per side), etc) are "too delicate". I mostly find this to be WRONG. A lower edge angle means there's less blade thickness to push through the thing you are cutting. Which means it will happen more easily. Which means you don't need to push as hard. This should lead to less fatigue for you. Interestingly, because you don't have to use as much force, you will tend to damage the blade *less* because when you hit the cutting board, it will mostly be with less impact than normal, which means your edge should last longer.

You might try lowering the edge angle on some of your blades by 5 degrees or so. Go from 20 dps to 15 dps. Or from 15 dps down to 11 or 12 dps. Edges in the 8 to 12 dps range REALLY cut.

I've never used a knife professionally at all, unless you count opening cardboard boxes on the job. So I don't claim any experience with meat cutting or any other high volume cutting jobs. But I've studied the craft of blade sharpening for quite some time and I think I know the basics pretty well. I hope this is helpful.

Brian.

 

[eKretz]

The problem he will have with going too low is that he might hit bone - which will nick an edge pretty readily. I agree otherwise. All of my daily use knives are sharpened to about 25°-30° inclusive, depending on intended use. Another thing to consider is to get the main body of the blade thinned out behind the edge. This makes a very noticeable difference in required pressure and knife control also. If I were in such a situation I might consider purchasing a few of my own knives to bring to work. Especially to get a little more hardness and edge life. And then I wouldn't let ANYONE else sharpen or even touch them.

 

[Jstanny88]

Thanks for the replies and info! I think you may be right about pressing too hard... because I believe that’s what happens when I start getting frustrated that it’s taking forever to change an edge from say 25 to 20. So a regular belt sander may be the way to go? Is there a way I could use a regular belt sander and not convex the edge? I’ve been looking at how factories sharpen knives and it seems like a lot of them use a belt grinder. Not really sure what the difference is but it looks like they go from a belt grinder to a paper wheel or polishing wheel. Maybe more of an industrial setup like that is what I need. And about the angles I don’t think trying a lower angle would hurt just because I’m on the gut line right now and there really isn’t any bone on that line... just guts (ewwwww lol). I wish I could bring my knives to work lol but unfortunately that’s against the policy.

Jesse

 

[bgentry]

So a regular belt sander may be the way to go? Is there a way I could use a regular belt sander and not convex the edge?

A regular sized belt sander (like a 1x42) is so powerful you won't need to use any real pressure. This should minimize the convex.

I’ve been looking at how factories sharpen knives and it seems like a lot of them use a belt grinder. Not really sure what the difference is but it looks like they go from a belt grinder to a paper wheel or polishing wheel.

As far as I know it's pretty typical for manufacturers to use a belt sander followed by a cotton buffing wheel. The purpose of the wheel is to remove the big burr that is formed during the edge grinding with the belt sander.

I believe Kershaw uses a grinding wheel instead of a belt sander. There are probably others doing something similar.

Good luck.

Brian.

 

[bucketstove]

Hi

BGA is cool and everything but it takes me forever to change an angle from like 25 to 20 degrees.

So you're going from
25 degrees inclusive ( 12.5degrees per side) to 20 degrees inclusive ( 10 degrees per side) ?
And its taking forever minutes (an hour)?
How wide is the edge bevel in millimeters?
What grit belt are you suing?


Regarding buying stuff, at most you only need a really coarse belt (P36) for thinning out the knife.

If I were you I would sharpen blade at 15 degrees per side (or 20 dps),
then paint blade with magic marker,
then using the coarsest belt,
grind at 10 degrees per side making sure you dont remove the last 1mm of marker.

That will leave your edge thick enough for bones, but thin enough to cut well, and sharpen up in reasonably quick

This is adding a relief grind, thinning behind the edge, fixing knife manufacturer mistake

 

[bgentry]

So you're going from
25 degrees inclusive ( 12.5degrees per side) to 20 degrees inclusive ( 10 degrees per side) ?

No, he's almost certainly talking about degrees per side. Because the BGA and all the rest of Work Sharp's powered sharpeners are marked in degrees per side.

Brian.

 

[Jstanny88]

Yeah I was talking about degrees per side. So I got a little curious about using a courser belt on the worksharp. I had to use the regular KO without the bga because I only have an old belt from my first work sharp sharpener at the moment... but it was a green 80 grit belt... so I took this Boker Kalashnikov that I’ve had for a while and man did I fuck it up lmao. I tried to dial in the angle to 17.5 and I ended up with a MONSTROUS BEVEL LOL. wtf did I do wrong? I still didn’t get a burr yet on it but it’s getting close to removing the sharpie... I gave up for the night lol... too frustrating. Now I gotta figure out how to thin the bevel lol which I don’t even know if It’s possible... or just get a new Kalashnikov

 

[bgentry]

Most of today's "tactical knives" have WAY overly thick blades. They look really strong and cool, but they aren't exactly good for cutting. If your Boker is like this (couldn't tell from a picture), you're going to find that the blade, right behind the edge, is very thick. Which means you will get a very large bevel compared to a thin blade.

For any given angle (like 17.5 in your case) the thicker the blade, the wider the edge bevel will be. So a 17.5 degree angle on a filet knife with thin stock will just be a small bevel, probably less than 1/16" wide. But on a very thick blade, that same 17.5 degree angle might produce a bevel that is 1/4" or wider. As a result many of these "tactical knives" come with really high edge angles: 25 degrees or higher (per side).

I would suggest playing with cheap knives to start. Do some experiments with them and you won't care when you make a mistake.

When sharpening a knife like this, it's helpful to try to find the existing angle first: Apply sharpie, set the WS to a somewhat high angle (say 25 dps). Then do a stroke or two with a FINE belt. See where the sharpie is being removed. Dial it in. Find that angle. Once you know the existing angle, then you'll know how much work it will take to get from where you are to your target angle.

If you are going to do this regularly, you should get some very coarse belts for the BGA. 80 grit is a nice start. I have some 60 grit belts for my WSKO (not a BGA) and they can really hog off metal when I need to. But again, a "real" belt sander will make this look like a toy.

Brian.

 

[Jstanny88]

Okay thanks Brian. That must just be the case with the thick stock. Cause I tried forever lastnight to pull up a burr at 17 degrees and couldn’t get the sharpie to remove for the life of me... then when I raised the WS angle up just barely ...BAMMM... burr lol. If I wanted it at 17 should I ha e just kept going? I’ll tinker with it tonight a little.

Jesse

 

[eKretz]

Try a fresh belt. Once the abrasives glaze, the belts slow quite a bit - especially when cutting a large surface area. I'll let you in on a little trick I've used often - once the belt glazes and slows down, get a diamond dresser like those used on grinding wheels and lightly run it over the belt while the belt is running. This will sharpen up the abrasive grains and let you use the belt a while longer. You can do this a couple times usually.