Sharpmaker on SFNO

Zookie

Zookie

Joined
Jan 26, 2012
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1,349
So I've already used my Busse SFNO to the point that it needed a little touch up. I took it to my Sharpmaker and used my fine and ultra fine ceramic sticks with no improvements at 40 degrees. It seems like 40 degrees isn't steep enough to touch the edge of the blade when sharpening.

I'm confused on what to do next, I have the diamond rods but don't know if that's a good idea to use it on the Busse. Any input? I've already searched this question on google with minimal results, but if there's already a thread on this please link it, I don't want to start thread that has already been discussed several times.

Thanks,
Zack
 
For a little touch up I will strop the edge regardless if it is convex or v- grind and I might do the same a few passes with a fine ceramic rod. I have used my sharp maker to touch up my B-11 and hand good results. When I use a jig of any kind I use a sharpie pen to mark the blade edge to see if I am going in the direction of progress I am seeking. I completely claim to know nothing about sharpening knives. Good luck
 
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-Use a sharpie to make sure you are hitting the apex.
-If you cant shave hair off your arm the edge is probably too far gone to just use the UF stones so you will want to start from the beginning.
 
lay the stones in the slots on the bottom and just use them like a flat stone, or you can just keep at it with the diamond stones until it is reprofiled. I like to knock down the shoulders between the primary and edge grind with something pretty course. This has a similar effect to convexing it, and if you decide to convex it, most of the work is already done
 
When you say the angle is'nt steep enough ... here is what I think is happening. 40 degrees inclusive is 20 degrees either side. If your SFNO has it's factory edge it is likely to be around 25 degrees either side or 50 degrees inclusive. So when sharpening the edge you are effectively re-profiling it by taking metal off the shoulder at first ... then eventually it would reach the main edge. In effect you would be increasing the steepness of the edge angle ( as opposed to saying the angle is'nt steep enough ... it is actually the other way round ).

The diamond rods and the coarse rods are both designed to "remove stock" ... that is what needs to be done to increase the edge profile. Busse give an initial obtuse edge at 50 degrees inclusive incase the user wants to chop heavy material like through a breeze block. For "wood" a 40 degree inclusive edge works better. Even better still is a 40 degree edge which is then taken higher at the shoulder using the 30 degree inclusive slots for 1/3 rd of the total side of the edge. In effect giving a secondary steeper bevel for the shoulder to enable less resistance to the cut or chop ... but retaining 40 degrees at the edge pinnacle to stop the edge from "rolling" under impact.

To achieve this in a uniform manner use a sharpie or marker pen on the edge and colour it black. Have to hand a small maagnifying glass or a jewellers loop to check the edge after sharpening for a while. You will see the ink removed from the shoulder initially and as more stock is removed the ink will gradually disappear towards the pinnacle. Once there is no ink left on the pinnacle you have a reprofiled edge. Re-apply the ink as and when you need to throughout the sharpening process to confirm where you are at in terms of progress.

The diamond and coarse stones are designed to do this job so I would'nt worry about using them. You can refine the toothy nature of the edge and give it some "finesse" with the fine and ultra fine once you have reached the edge pinnacle.

When this task is done the knife will be much easier to restore the edge with a few simple passes on the fine ceramic sticks. The angles will then match and usually all that is needed is to restore the edge pinnacle.

Some do this stage easiest by stropping the edge freehand on a leather strop loaded with fine chrome based paste. Strops can be found from suppliers like "knivesshipfree.com" together with paste. Use the green coloured fine paste for this task.

If you reprofile your edge to a 40 degree inclusive with a 30 degree 1/3 rd shoulder bevel and then do a little stropping it will blend the two angles together to a nice convex curve.

After 7 yers of sharpening Infi on all manner of mid range to large knives the 40 degree/30degree back bevel has proved to be the best combination for long term use.

Going finer ( i.e. totally 30 degrees inclusive ) is counter productive. The edge "rolls" too soon thus limiting the time of use before needing to be stropped back into alignment.

40 degree inclusive at the pinnacle enables the edge to be worn away by "use" as opposed to rolled away by the force of cutting or chopping wood at an angle.

Good luck on the re-profile and let us know how you get on. :thumbup:
 
Thanks for all the info guys. I didn't even notice that flat part on the sharp maker till now ;)
 
What a wonderful reply, this made total sense to someone who doesn't know shit about sharpening. So I should sharpen the knife with the diamond rods on the 40 degree slots and then take the ceramic fine and ultra fine rods on the 40 degree slots as well?


PeterPHWS said:
When you say the angle is'nt steep enough ... here is what I think is happening. 40 degrees inclusive is 20 degrees either side. If your SFNO has it's factory edge it is likely to be around 25 degrees either side or 50 degrees inclusive. So when sharpening the edge you are effectively re-profiling it by taking metal off the shoulder at first ... then eventually it would reach the main edge. In effect you would be increasing the steepness of the edge angle ( as opposed to saying the angle is'nt steep enough ... it is actually the other way round ).

The diamond rods and the coarse rods are both designed to "remove stock" ... that is what needs to be done to increase the edge profile. Busse give an initial obtuse edge at 50 degrees inclusive incase the user wants to chop heavy material like through a breeze block. For "wood" a 40 degree inclusive edge works better. Even better still is a 40 degree edge which is then taken higher at the shoulder using the 30 degree inclusive slots for 1/3 rd of the total side of the edge. In effect giving a secondary steeper bevel for the shoulder to enable less resistance to the cut or chop ... but retaining 40 degrees at the edge pinnacle to stop the edge from "rolling" under impact.

To achieve this in a uniform manner use a sharpie or marker pen on the edge and colour it black. Have to hand a small maagnifying glass or a jewellers loop to check the edge after sharpening for a while. You will see the ink removed from the shoulder initially and as more stock is removed the ink will gradually disappear towards the pinnacle. Once there is no ink left on the pinnacle you have a reprofiled edge. Re-apply the ink as and when you need to throughout the sharpening process to confirm where you are at in terms of progress.

The diamond and coarse stones are designed to do this job so I would'nt worry about using them. You can refine the toothy nature of the edge and give it some "finesse" with the fine and ultra fine once you have reached the edge pinnacle.

When this task is done the knife will be much easier to restore the edge with a few simple passes on the fine ceramic sticks. The angles will then match and usually all that is needed is to restore the edge pinnacle.

Some do this stage easiest by stropping the edge freehand on a leather strop loaded with fine chrome based paste. Strops can be found from suppliers like "knivesshipfree.com" together with paste. Use the green coloured fine paste for this task.

If you reprofile your edge to a 40 degree inclusive with a 30 degree 1/3 rd shoulder bevel and then do a little stropping it will blend the two angles together to a nice convex curve.

After 7 yers of sharpening Infi on all manner of mid range to large knives the 40 degree/30degree back bevel has proved to be the best combination for long term use.

Going finer ( i.e. totally 30 degrees inclusive ) is counter productive. The edge "rolls" too soon thus limiting the time of use before needing to be stropped back into alignment.

40 degree inclusive at the pinnacle enables the edge to be worn away by "use" as opposed to rolled away by the force of cutting or chopping wood at an angle.

Good luck on the re-profile and let us know how you get on. :thumbup:
Click to expand...
 
Zookie said:
What a wonderful reply, this made total sense to someone who doesn't know shit about sharpening. So I should sharpen the knife with the diamond rods on the 40 degree slots and then take the ceramic fine and ultra fine rods on the 40 degree slots as well?
Click to expand...

Yes that is right :thumbup: Start off with the diamond rods ... take the stock removal to the pinnacle. Then use a few passes on the coarse rods to reduce the toothy nature of the diamond rods. Then refine this with the fine and then the ultra fine. Gradually reducing the coarseness of the grit polishes the edge and this enables a smoother cut ( do a few cuts on some newspaper and you will feel the edge cut with less resistance ). The fine or ultra fine can be used to really give the edge a serious "razor sharpness" by using alternate "light" strokes. When it cleans arm hair like a straight razor would it is sharp enough :D

P.S. The task of removing stock and reprofiling can be a long one. Use the sharpie and ink removal to see that you are gradually making progress. The task may take a few hours or a few goes at it for shorter periods and just return to it as and when you have the time. Once the re-profile is done "sharpening" should take no more than 15 to 20 mins. Infi sharpens fast once the angles all match. The re-profile though is a labour of love :)
 
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Zookie said:
What a wonderful reply, this made total sense to someone who doesn't know shit about sharpening. So I should sharpen the knife with the diamond rods on the 40 degree slots and then take the ceramic fine and ultra fine rods on the 40 degree slots as well?
Click to expand...


Yes, that will work.

What Peter is suggesting is to reprofile the edge at 30 degrees inclusive, and then finish off by doing the very edge at 40 degrees. IIRC, the sharpmaker instructions describe this process. Either way the edge will be a better cutter than the factory angle, assuming that cutting bricks is not your typical use. Be sure to use the Sharpie trick, so that you can see where the stones are working.

Eventually, Last visible Canary will be along with some nice drawings.
 
What I am suggesting is to use the 40 degree slots for the re-profile. The 30 degree slots are only to be used once the 40 degree edge is established. They are used just to round off the outer shoulder of the edge for 1/3rd of the total of each 40 degree inclusive side.

Don't use the 30 degree slots to re-profile and then the 40 degree slots to create the pinnacle. You are unnecessarily losing more metal on the edge if you take it to 30 degrees at the pinnacle and then take more off to bring it down to 40 degrees.

You can do it that way but it will take a fair bit longer and waste metal on the edge.

Go with 40 degrees and then just use the 30 degree slots to reduce the shoulder angle.

Resinguy is right though about LVC ... he has some great diagrams to explain this sort of thing. Words can do it if you are clear in what you say but a diagram is often worth a thousand words :D
 
resinguy said:
Yes, that will work.

What Peter is suggesting is to reprofile the edge at 30 degrees inclusive, and then finish off by doing the very edge at 40 degrees. IIRC, the sharpmaker instructions describe this process. Either way the edge will be a better cutter than the factory angle, assuming that cutting bricks is not your typical use. Be sure to use the Sharpie trick, so that you can see where the stones are working.

Eventually, Last visible Canary will be along with some nice drawings.
Click to expand...


30 degrees inclusive? So I put the diamond rods on the 30 degree slot instead of the 40 degree?
 
PeterPHWS said:
What I am suggesting is to use the 40 degree slots for the re-profile. The 30 degree slots are only to be used once the 40 degree edge is established. They are used just to round off the outer shoulder of the edge for 1/3rd of the total of each 40 degree inclusive side.

Don't use the 30 degree slots to re-profile and then the 40 degree slots to create the pinnacle. You are unnecessarily losing more metal on the edge if you take it to 30 degrees at the pinnacle and then take more off to bring it down to 40 degrees.

You can do it that way but it will take a fair bit longer and waste metal on the edge.

Go with 40 degrees and then just use the 30 degree slots to reduce the shoulder angle.

Resinguy is right though about LVC ... he has some great diagrams to explain this sort of thing. Words can do it if you are clear in what you say but a diagram is often worth a thousand words :D
Click to expand...


Ah, my mistake, I misunderstood the order of events. That's a different way of doing it.


Zookie said:
30 degrees inclusive? So I put the diamond rods on the 30 degree slot instead of the 40 degree?
Click to expand...


No, see Peter's clarification above.
 
I prefer to do the back-bevel first because it reduces the amount of, time you are dealing with the actual edge. The precision of the back bevel is less critical than the edge. Either way works. my way works better if you are impatient, inconsistant, or less skilled. If you are really precise, setting the edge first will remove a little less metal.
 
If speed is your goal it is quicker to reduce a 50 degree inclusive edge to 40 degrees than it is to reduce it to 30 degrees and then reduce that to 40 degrees for 2/3rds of the edge.

If you mean you prefer to do a 30 degree back bevel first and then do "at the appropriate time" the 40 degree edge then I suspect they are going to be the same on time because the amount of metal removed will be the same ... it is just the order of doing things that changes ... but it is harder to judge when you have the back bevel "just right" to commence the main edge IMO doing it this way ...

When it comes to sharpening .... precision actually does give you "speed" ... change the angles by going too quick and you can knock your work back to a 50 degree starting point if you're not careful ...
 
that's kind of what I mean, quickly knocking the shoulders down, then taking my time backing the now-thinner 50 back to 40.
 
I have even alternated before, when I thought the back bevel was deep enough but changed my mind and decided to thin it out more. I think the key is slowing down and taking your time any time you are close to your final bevels, or any time you are working the edge bevel.
 
darkaether said:
I have even alternated before, when I thought the back bevel was deep enough but changed my mind and decided to thin it out more. I think the key is slowing down and taking your time any time you are close to your final bevels, or any time you are working the edge bevel.
Click to expand...

Yes, I agree. Slow and steady wins the day once you are close to final bevel finishing.:thumbup:
 
Does anyone have videos they want to share? I'm a pretty visual person when it comes to learning new things and good video of all the above would be awesome.
 
Here is a link to the Spyderco Sharpmaker DVD which comes with it ... it is one of four but the others should show up for ease of clicking on when the first one finishes.

http://www.youtube.com/watch?v=GB0r6GvESGg

The use of a sharpie or marker on the edge and looking at how the ink is removed by gradually re-profiling the edge can be seen here from a pic I did for someone wanting a tutorial on using a Lansky system ...

This was my first Busse, a Skinny Ash, I wanted to thin the edge down to a 40 degree bevel. The ink from the marker in the pic below spilled onto the blade flat but you can see from the first few strokes where the shoulder of the edge is and how this is being worked on by the stone.

100_0192.jpg


This pic shows the edge in it's final phase, the ink has nearly all been removed towards the pinnacle. Now is the time you would move to finer stones to polish the edge. When the angle of the stone and edge are exact a few strokes should remove all the ink on the edge. This lets you know it is time to polish the edge and refine it for razor sharpness.

100_0190.jpg
 
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