Help with sharpening...

L

learnme

Joined
Oct 30, 2009
Messages
116
Hi all,
I have recently gotten my new F1 3g and a DC4 sharpening block. Before even thinking of taking my new love to the block i need to practice/learn how to convex sharpen. I have a few questions and I hope someone would care to drop their 2 cents

1. Is the DC4 enough to properly maintain the Fallkniven F1 3g?

2. The instructions that came with the block and on Fallknivens website say that when sharpening, i should "move the knife in circular motions". This contradicts everything I have watched and read on convex sharpening though Fallkniven only produces convex ground blades. thoughts on this?

3. I practiced with one of our very dull and chipped kitchen knives but cant seem to get it to even cut paper after spending about 15min on the block. I managed to smooth out some of the chips though some really small ones remain. The angle i decided to use was by laying the knife flat and raising it up to approximately the width of the spine. Pulling back only, and trying my best to remember to only use the knifes weight. WHAT AM I DOING WRONG? Any tips?

4. a) Is pulling or pushing better for a convex?
b) Should I spend more time on the diamond or ceramic side?
c) How can I tell if I am even doing it right?

5. Lastly, i noticed in the beginning of my sharpening, i would lay the knife flat, pull back, and gradually raise the spine till it "bites" then stop raising and just follow through with the pull. Is this a good approach? After some time the "bite" would feel more smooth and im guessing this is because the knife was getting sharpened? Is it accurate to say that the friction between the block and the blade decreases the more the knife is sharpened and that that is a good indication of knowing where to sharpen on a knife?

Again, any and all feedback is welcome.
 
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for maintaining a convex edge it's best to use sandpaper and a mousemat.

the DC4 will serve you for your regular freehand sharpening but will put a V-grind on your F1, unless you use a technic to keep it convex on a benchstone. I'd use the DC4 for field use touch ups and when back home the sandpaper/mousemat for making the edge convex again

My 0.02$
 
Honestly, I recommend you regrind the bevels to a V or saber grind. It is much easier to maintain. Convex edges are a good choice for folks with belt grinders, not a very good choice for people who do manual sharpening. Personally, I have a belt grinder but I won't use it to sharpen my knives. It is only for sharpening other peoples knives and heavier grinding tasks. I regrind all convex bevels for ease of maintenance.
 
learnme said:
Hi all,
I have recently gotten my new F1 3g and a DC4 sharpening block. Before even thinking of taking my new love to the block i need to practice/learn how to convex sharpen. I have a few questions and I hope someone would care to drop their 2 cents

1. Is the DC4 enough to properly maintain the Fallkniven F1 3g?

2. The instructions that came with the block and on Fallknivens website say that when sharpening, i should "move the knife in circular motions". This contradicts everything I have watched and read on convex sharpening though Fallkniven only produces convex ground blades. thoughts on this?

3. I practiced with one of our very dull and chipped kitchen knives but cant seem to get it to even cut paper after spending about 15min on the block. I managed to smooth out some of the chips though some really small ones remain. The angle i decided to use was by laying the knife flat and raising it up to approximately the width of the spine. Pulling back only, and trying my best to remember to only use the knifes weight. WHAT AM I DOING WRONG? Any tips?

4. a) Is pulling or pushing better for a convex?
b) Should I spend more time on the diamond or ceramic side?
c) How can I tell if I am even doing it right?

5. Lastly, i noticed in the beginning of my sharpening, i would lay the knife flat, pull back, and gradually raise the spine till it "bites" then stop raising and just follow through with the pull. Is this a good approach? After some time the "bite" would feel more smooth and im guessing this is because the knife was getting sharpened? Is it accurate to say that the friction between the block and the blade decreases the more the knife is sharpened and that that is a good indication of knowing where to sharpen on a knife?

Again, any and all feedback is welcome.
Click to expand...
Convexing with a stone is a bit harder to get the feel for as a beginner, but you do have the basic grasp of one of the techniques.
 
Knife Outlet said:
Honestly, I recommend you regrind the bevels to a V or saber grind. It is much easier to maintain. Convex edges are a good choice for folks with belt grinders, not a very good choice for people who do manual sharpening. Personally, I have a belt grinder but I won't use it to sharpen my knives. It is only for sharpening other peoples knives and heavier grinding tasks. I regrind all convex bevels for ease of maintenance.
Click to expand...


EXCELLENT ADVICE! :thumbup::thumbup::thumbup:
 
oh no no..dont get talked out of a convex grind. if you change the knife to a v grind or flat grind you are ruining one of the key benefits of your knife. its not at all hard to sharpen even with a stone. the infamous ed fowlers directions go like this. sharpen your edge just like normal but on ever 3rd stroke or so tilt the spine down to knock off any shoulder thats forming. this will keep it rounded off and smooth and maintains the convexed edge. he uses a norton india stone...ive used this same technique and it works fantastic.
 
justintyme said:
oh no no..dont get talked out of a convex grind. if you change the knife to a v grind or flat grind you are ruining one of the key benefits of your knife. its not at all hard to sharpen even with a stone. the infamous ed fowlers directions go like this. sharpen your edge just like normal but on ever 3rd stroke or so tilt the spine down to knock off any shoulder thats forming. this will keep it rounded off and smooth and maintains the convexed edge. he uses a norton india stone...ive used this same technique and it works fantastic.
Click to expand...

Yea, that's why I haven't replied yet, one of the MAIN reasons i got this knife is because of the convex grind. Now i guess I will wait and see if anyone is willing to answer the questions... :(
 
justintyme said:
oh no no..dont get talked out of a convex grind. if you change the knife to a v grind or flat grind you are ruining one of the key benefits of your knife. its not at all hard to sharpen even with a stone. the infamous ed fowlers directions go like this. sharpen your edge just like normal but on ever 3rd stroke or so tilt the spine down to knock off any shoulder thats forming. this will keep it rounded off and smooth and maintains the convexed edge. he uses a norton india stone...ive used this same technique and it works fantastic.
Click to expand...

That is simply not true. The purported advantage of the convex grind is that it is stronger. The reason it is stronger is that the edge is at a more obtuse angle (i.e. it is duller.) You can apply that same angle to a saber grind as a secondary bevel and have the blade just as dull and just as strong.

The real advantage of the convex grind is that it is easy to apply with a belt grinder so the manufacturers like it for that reason. All of them use power equipment to apply edges to blades. All the other things said about the convex grind are, frankly, fluff. Whoever sold it as a benefit was obviously very successful. Whenever I get a convex edged blade, I immediately regrind the bevel. Not only do I get a blade that is easier to maintain but I get a sharper edge as well.
 
learnme said:
Yea, that's why I haven't replied yet, one of the MAIN reasons i got this knife is because of the convex grind. Now i guess I will wait and see if anyone is willing to answer the questions... :(
Click to expand...

Dont worry about which edge to choose. Put your efforts into creating a sharp edge that lasts. Much of the debates on these kind of forums are a form of mental illness.
 
When old knives come my way, the first thing I do is study the sharpening methods of the previous owners and I come to know their sharpening knowledge and when I see one that has been treated special I have a good idea of the use she has known.

Convex blades are easy to sharpen, you can use 320 grit sandpaper on any flat surface or a stone. Keep the surface of your stone clean, I use kerosene or simple green to clean my stone. A stone filled with grit does not do much and only increases the need for extra labor on your part. The sand paper can be easily and cheaply replaced. If you need to remove some deep chips, just use a coarser sand paper, then finish with the 320grit for an aggressive edger, or a fine grit as you wish.

I tell folks that if they can strike a match they can sharpen a knife and if they practice it will come. Your decision to practice on old knives is a good one - my suggestion is to have fun with it and you will know when you have achieved your goals.

Slice paper, cut rope, carve wood as test material and it won't take long to know how you are progressing in developing one of the most singnificant aspects of using a knife.

You can do anything on a stone to develop and maintain an edge that I can do on a belt grinder - and more!

Some old knives have striations all the way to the spine and still maintain a convex blade. The initial sharpening bevel is gracefully blended into the rest of the blade to minimize the influence of the secondary bevel created in sharpening the edge.

If you ever find your way to Riverton Wyo. stop by for a quick lesson or two.

Good Luck and remember the fun is in the learning.
 
The advantage of a convex edge in cutting was found out hundreds of years ago by japanese sword makers. Convex edges are very effective and can be just as sharp as any other edge.
 
Mr Fowler died in the Civil War - please call me Ed.

You can pretty much bet the convex blades have been in existence since the beginning of man - so incidentally was the drop point blade! (smile).

Just for grins, I would bet that the strongest influence in flat grinds shortly followed the development of saw blades!! That thought just hit me! had to share it.
 
knifenut1013 said:
The advantage of a convex edge in cutting was found out hundreds of years ago by japanese sword makers. Convex edges are very effective and can be just as sharp as any other edge.
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Not just the Japanese, either. European edged weapons from the iron age onward had mostly convex edges as well. I was under the impression that the modern flat-bevelled edge was, in fact, adopted only in the past centruy as a way to ease the mass production process. :confused:

At any rate, I can't help you with convexing on stones, learnme, but I will definitely add my voice to those saying KEEP IT CONVEX! :thumbup:
 
Thanx for all the feedback! A special THANK YOU to Ed for his initial post. That was very kind of you sir to share that with us and extend and invitation. Unfortunately, Sweden is a bit far from Riverton. Maybe one day. In any account, I have been practicing and have gotten our beat up kitchen knife quite sharp now. It was dull as a brick and chipped pretty bad. Now it cuts quite well and has only a few minor chips left. I still cant get it to be razor sharp though. Any tips? The only way I got it to be as sharp as it is now was by using the marker method where I marked the edge to see where I was actually sharpening. I was surprised to see just how high an angle I had to go. It was about 40 deg! I used the same method on my swiss army knife and i got it semi razor sharp. I could cut hairs off my arm but nothing like the F1. Again, what am i doing wrong? Lastly, how could I or anyone, determine what angle to sharpen their knives? If I never used the marker method I would have ground that kitchen knife so much I would have created a new edge. As always, any advice and feedback is welcome. Thanx!
 
Hard to explain without you watching my hands - but here goes.
40 degrees is way too much for a slicing edge, but don't get hung up (for example) on the difference between 17 and 23 degrees, etc. You can learn your angle by cutting as your experience indicates.

With a chipped edge I start out with a coarse stone, use both hands on the blade to apply pressure and work the chips out. I work alternatively from side to side. Keep your stone clean, apply simple green or what ever you are using and wipe the stone with a cloth to keep it clean so it can cut.

You will know when you have developed the best edge that blade can support when you have developed a wire edge on one side. You can feel this by running your fingers from spine over the edge. Develop the wire on one side, then on the other side, then using only the weight of the blade raise your angle and cut the wire edge off - you can also take it off slicing hard wood but the stone is quicker.

If you have developed a secondary edge on the blade (usually happens) go back and blend the edge to the rest of the blade. The edge does not have to be exactly - precisely - the same from side to side. Contrary to popular belief cut is not a high precision operation. Unless you are doing really delicate carving you will never notice the difference between a few degrees.

On my working knives I like to keep about a 40 degree bevel around the point, this keeps strength at the tip where it is needed to get you into your work.

The most important aspect of learning how to sharpen is practice and immediate feedback concerning your results. Sharpen, cut and back again, it is like playing a piano or riding a bicycle - takes practice. My grandmother could sharpen a kitchen knife on the back step and slice tomatoes with precision. I assure you there is nothing to it.
 
Ed Fowler said:
Hard to explain without you watching my hands - but here goes.
40 degrees is way too much for a slicing edge, but don't get hung up (for example) on the difference between 17 and 23 degrees, etc. You can learn your angle by cutting as your experience indicates.

With a chipped edge I start out with a coarse stone, use both hands on the blade to apply pressure and work the chips out. I work alternatively from side to side. Keep your stone clean, apply simple green or what ever you are using and wipe the stone with a cloth to keep it clean so it can cut.

You will know when you have developed the best edge that blade can support when you have developed a wire edge on one side. You can feel this by running your fingers from spine over the edge. Develop the wire on one side, then on the other side, then using only the weight of the blade raise your angle and cut the wire edge off - you can also take it off slicing hard wood but the stone is quicker.

If you have developed a secondary edge on the blade (usually happens) go back and blend the edge to the rest of the blade. The edge does not have to be exactly - precisely - the same from side to side. Contrary to popular belief cut is not a high precision operation. Unless you are doing really delicate carving you will never notice the difference between a few degrees.

On my working knives I like to keep about a 40 degree bevel around the point, this keeps strength at the tip where it is needed to get you into your work.

The most important aspect of learning how to sharpen is practice and immediate feedback concerning your results. Sharpen, cut and back again, it is like playing a piano or riding a bicycle - takes practice. My grandmother could sharpen a kitchen knife on the back step and slice tomatoes with precision. I assure you there is nothing to it.
Click to expand...


Easily one of the most practical posts Ive read in a long while. Sums up my own personal experiences in sharpening to a "T". Always thought I was a little off cause I couldn't tell ya for sure if that edge I just did was 18 or 21 deg, or if one side was a tick steeper or shallower than the other. But they still cut like a laser haha. Anyhow, excellent post sir. :D
 
You've gotten a lot of good advice on both v grinds and convex grinds. You might want to consider these contrasting posts. If you don't want particular advice in one area or another, it helps to say that right up front, it prevents aggrevation and flame wars on both sides.

learnme said:
Again, any and all feedback is welcome.
Click to expand...

learnme said:
Yea, that's why I haven't replied yet, one of the MAIN reasons i got this knife is because of the convex grind. Now i guess I will wait and see if anyone is willing to answer the questions... :(
Click to expand...
 
Another aspect of the wire edge: If you can take it off in one long piece ( like a hair) the blade will not have a great cutting potential. When the wire edge comes off in microscopic particles you have a fine grained steel and usually cuts very well.

This is not an absolute rule, but I have not found many exceptions.
 
I believe that "V" bevels have been around several millenia longer than convex. :D

I've never seen a flint or obsidian knife, arrowhead, or spearpoint that was convexed! :p
 
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