Need help on my tuning sharpening of my Gransfors SFA..its better but not great

[T-Dog]

So I have used my SFA enough over the past few months that I wanted to tune the edge back up on my 800-1000-6000 grit King waterstones and then strop it a little. I have never done this before and honestly was a little intimidated but need to do it. I watched Ray and a few others on youtube and it seems as though the masses seemed to agree that doing a circular stroke up close to the business end is the way to go because of the inconsistency of the angle it encourages a slight convex shape so there was no issue there. Well let me back up because there was an issue straight from the factory because the cutting line jogged over almost 1/8 of an inch from top to bottom if I looked down on it from above so I had to remove a fair amount of metal to true and straighten the line but not a huge deal. Where I am having trouble is whether I should try and do the Ray Mears slicing technique like you would typically do with a knife or do many of you just continue the circular motions all the way down to the tip. I tried both and obviously need more practice because it is definitely sharper and will kind of slice paper and will cut paracord with ease but shaving sharp...not really. Right now I can go either way/style but want to see what you prefer and why. Furthermore are there any tricks to maintaing consistent angle? I don't think I did a very good job and was honestly surprised at the results and thought maybe the the subtle variations in angle are less important on an axe. Thanks in advance.

 

[Liam Ryan]

The GB axes are convex, I would just be using a mousepad and sandpaper, or my compound strop for even quicker touch ups.
Here is a good video for you though, the marker is a good idea for keeping the angle right. Remember to use oil or water for your stone, and strop off that rolled over edge.
[youtube]AKJhhz-643k&feature=fvwrel[/youtube]

 

[Square_peg]

Furthermore are there any tricks to maintaing consistent angle?

Best trick for maintaining a consistent angle is practice, practice, practice. It comes naturally after a while. But in truth, I started using guides. Sharpen everything in the house for practice. Your kitchen knives - all razors. Hunting knives, pocket knives, whatever you've got - sharpen them. Get a couple of cheap knives and grind away if you don't want to wear out your good knives in practice.

My preferred method of honing an axe is to hold it in a vise or clamped to the edge of the bench and then hone with a water stone. Once you get a little slurry worked up the stone cuts pretty quick.

The angle/shape of the bit should be set with your file. The honing is just to fine tune and finish the edge. I've posted a picture of a axe sharpening guide several times on these forums. It's from the Forest Service publication 'An Ax to Grind'. Get the shape shown with your file.

When you switch from the file to the stone you should be able to feel the difference between when the stone is biting the edge and when it's honing behind the edge. I aim for just behind the edge and and hone until I feel the stone contacting the edge. Then flip the axe over and repeat. Flip again when you go to the next finer grit, etc.

There's a lot more to it than this but I don't want to sit here and write a book. Most of it will come naturally to you with practice. There are many other methods that will produce excellent results. Try a few methods and see if one feels natural to you.

 

[T-Dog]

Square Peg....I to use many guides and have great success, I have and edge pro, and a wicked edge that I absolutely love and use extensively but I do freehand more and more and do that on almost all of convex edges. Because of using good systems and guides I have high expectations of my edges and like to get to that point with as little fuss as possible. The reason I am going freehand when I have time is to not be totally dependent on a "system" in case it fails or I don't have it with me but I am taking it in stride since I am extremely busy and cannot be a purist expert on everything...(I have a lot of hobbies). However with my axe I don't have a system and want to avoid the pitfalls of failed exercises and techniques so with that being said here comes a few questions for ya. What kind of motion are you using on the stone when your are at and feel the cutting edge, are you going circular or doing one continuous cut along the edge? Do you let your slurry stay on as long as possible on all grits, because I tended to wash it away often thinking I was rinsing metal particles away thus exposing more unclogged cutting surface.

I did watch that video above a few times and like the marker idea and use it often on other tools and did on my axe but don't like the holding technique since there are too many moving parts in that equation to allow for any kind of consistency.

 

[M3mphis]

I don't usually bother putting full size axes on my waterstones. It's too awkward, so I just use a hand held oilstone, followed by fine and extra fine diamond hones, followed by a few strokes on a ceramic rod. I use a circular motion. My full size axes will easily shave with this cheap, low tech method. The ceramic rod is the key for me. It removes any leftover burr and aligns the edge like a steel. Very "low fuss."

For my carving hand axes, I put them on the japanese waterstones, but I file most of them to flat bevels.

I'm not a huge fan of sharpening anything convex on my japanese waterstones because they are so soft that you have to be very dainty on the very edge or you'll actually dull the edge by applying too much pressure.

Pretty rambling, but maybe there will be something useful in there.

Matt

ETA: To clarify, I don't use the ceramic rod in a circular motion...just the stones. The rod I use just like a steel. Also, regarding the softness of waterstones, that is why I like to use diamond hones held in the hand on full size axes. You really can't screw up too badly by using too much or too little pressure.

 

[T-Dog]

The very first time that I tried to work the actual edge on my 6000 waterstone I had too much pressure and angle to the point that I actually made a small gouge in the stone and rolled the edge. I really like the idea of the diamond abrasives. Regarding the ceramic rods my spyderco triangular ceramics should work fine, correct? That was not rambling Matt, made perfect sense, thanks.

 

[pialia]

I have a GB Wildlife Hatchet and I've messed it up pretty bad smashing it into rocks etc. I friggin' love the steel, 1-2 minutes per side on 120 grit sandpaper, followed by 1-2 minutes per on 320, 600, 1200, 1500, 2000 and some stropping and it's more or less equal to what a brand new Mora usually is. Shaves with ease, cuts phonebook paper like it's nothing even though the thickness kind of gets in the way.

I usually just place the sandpaper on my desk with no backing, I figure the inconsistencies in my technique convex it enough and it seems to be working. I've used a mousepad backing and all it seems to do is remove some of the sharpness and I get a more rounded off edge. I usually don't use anymore pressure than the weight of the axe itself provides. I usually go edge leading-trailing-leading-trailing-leading-trailing type strokes, sometimes I'll finish it with some trailing strokes on the higher grits, but I don't notice much different.

I really can't think of an easier and cheaper way to get big tools like axes sharp than using just plain 'ole sandpaper. Not great for field touch-ups though

 

[Square_peg]

Square Peg.... What kind of motion are you using on the stone when your are at and feel the cutting edge, are you going circular or doing one continuous cut along the edge?

For years I've been a proponent of continuous cut method. It's still the only method I use on my knives. But with axes I'm getting quicker better results with a circular motion on the first couple of grits. But I always finish the edge with continuous cut strokes.

In the past I've always finished my edges with a steel or with a diamond hone and then a steel. Recently I picked up a hard Arkansas stone at an estate sale which I'm guessing is 6000-8000 grit. My axes all get finished with that stone now - using the continuous cut method. It leaves the edge frighteningly sharp.

 

[T-Dog]

Square Peg...

I am assuming then that the motion of the stone on the cut stroke travels from cutting edge to poll, correct? If a person were to go in the opposite direction other then a larger bur to be removed later is there any other negative effect? I am not saying that I would try to go that way but like to understand the principal behind it. On my edge pro most of the cutting is on the forward stroke away from the edge but on my wicked edge is is just the opposite.

 

[Square_peg]

I am assuming then that the motion of the stone on the cut stroke travels from cutting edge to poll, correct?

Yes, that's correct.

The reason (as I understand it) for honing in this direction is same as why we use this direction for knives. This motion removes worn metal from the blade rather than pushing the worn metal out to the tip of the blade. If you draw a knife across the stone in the direction opposite of the cutting motion then at the microscopic level weakened steel is forming the cutting edge.

There was an excellent article about this in Popular Science back in the mid-70's. It included photos of edges at 300-1000 times magnification and showed the difference between various sharpening techniques. It was after studying that article that my sharpening skills improved dramatically. Of course I'm sure there are even better discussions on sharpening available now. Whatever works.

 

[daizee]

So far I've been using a circular motion with a rectangular two-sided stone. I do coarse, then fine. Fine is usually enough for a touch-up. It works pretty well. Then I strop on a medium (600?) nail file pad, then on the nail buffing pad. That gets the wire edge off and I've been happy with the results. I don't try to get my axes hair-splitting sharp as I sometimes do with my knives, but they do have to cut paper cleanly apart from any chips I may decide to leave in (which will get sharpened out eventually).

 

[garry3]

For maintenance I like to take the stone to the axe. Bit faceing up so I can look down it, circular motions. Can't really go wrong or screw anything up. Not sharp enough? Just use a harder stone or strop if you want it to multi task as a razor.