Having trouble sharpening a Wenger Patriot

[sldk]

I recently purchased a Sharpmaker, and am in the process of sharpening some of my older knives that are in fairly rough shape. I've watched the DVD, as well as some other YouTube videos on how to use it effectively

My first test was a Victorinox Camper which I didn't have much trouble getting the main blade hair shaving sharp with a 40deg inclusive edge using the following technique:

1. Color the bevel with a Sharpie
2. 3-5 passes on the corner of the grey/brown stones to check the angle
3. 20-25 passes on the corner of grey/brown stones (the blade was in really rough shape)
4. 15-20 passes on the flats of the grey/brown stones
5. 15-20 passes on the corner of the white stones
6. 15-20 passes on the flats of the white stones

All strokes are applied with light pressure, barely more than enough to keep the blade in contact with the stone.

I've applied the same technique with my Wenger Patriot, but after spending at least an equal amount of time, it still can't push cut paper. It's barely sharper than a butter knife.

Any ideas what I could be doing wrong?

 

[bucketstove]

I recently purchased a Sharpmaker, and am in the process of sharpening some of my older knives that are in fairly rough shape. ...
I've applied the same technique with my Wenger Patriot, but after spending at least an equal amount of time, it still can't push cut paper. It's barely sharper than a butter knife.

Any ideas what I could be doing wrong?

You are doing nothing wrong, the knife just need more time on the coarsest stones, the brown stones

Instead of doing one pass then switching sides, do 100 passes or more,
however many it takes to raise a burr,
only then do you switch sides , until you raise a burr

once you raise a burr, then you can do your regular routine with light passes and onto finer stones

No, I don't own a sharpmaker, but this is like 99% of sharpmaker problems, the knife has an obtuse angle greater than 20dps, so it needs a lot of work before sharpmaker can sharpen it, you may need coarser stones
(like sharpmaker diamond, or wrap some 150grit-300grit sandpaper around your rods)


sharpmaker medium rods 12.5 +/- 1.0 micron or P1500 grit or J1200
sharpmaker fine rods 6.5 +/- 1.0 micron or P2500-P3000 or J2000-J2500


this is assuming you are keeping this "patriot" knife vertical when sharpening

you could always put some paper under one corner of sharpmaker to increase the angle to 25 ...
or turn the sharpmaker to get same effect

 

[bgentry]

Either the blade is REALLY dull, or the angle is larger than 20 degrees per side.

When you used sharpie on the edge and then did some passes on the SharpMaker, did the sharpie come off cleanly all the way to the edge? Or was some sharpie left over at the very edge of the edge?

Brian.

 

[sldk]

Thanks for the feedback folks.

I don't have a magnifying glass or loupe, but I'm fairly certain all the Sharpie is coming off.

I do have coarse stones as well, so I'll try moving to those.

 

[DeadboxHero]

You are doing nothing wrong, the knife just need more time on the coarsest stones, the brown stones

Instead of doing one pass then switching sides, do 100 passes or more,
however many it takes to raise a burr,
only then do you switch sides , until you raise a burr

once you raise a burr, then you can do your regular routine with light passes and onto finer stones

This is crucial.

 

[sldk]

Thanks again for the feedback. I'll try just doing one side at a time until i raise a burr.

 

[bgentry]

I don't have a magnifying glass or loupe, but I'm fairly certain all the Sharpie is coming off.

I do have coarse stones as well, so I'll try moving to those.

Sometimes it's hard to see if the marker is really coming off without magnification. So here's another test:

Hold the knife with the blade edge straight up. Spine facing the floor, edge facing the ceiling. Now stand under bright light and try to see if you can reflect light off of the edge of the blade. Rock the blade up and down (tip towards the floor, then tip towards the ceiling). If you can see reflected light, the edge is fairly thick and "dull". As you do work on the sharpmaker (or stones) the reflection will gradually get smaller as you make the edge thinner. Eventually it will disappear completely. At that point the blade should be rather sharp.

If you can't see reflected light, then the blade is already pretty sharp, or perhaps you're not doing the test correctly. If you want to be super sure, and you're willing to experiment, cut the blade edge *lightly* into the side of a sharpmaker rod 2 or 3 times. That should flatten the edge enough to be VERY dull and reflect light easily. Then you can do work on the blade and watch the reflection disappear. All of this assumes that the edge angle is less than 20 dps.

Brian.

 

[sldk]

Ah, thanks for the tip. I'll use that test as well.

 

[Obsessed with Edges]

Thanks for the feedback folks.

I don't have a magnifying glass or loupe, but I'm fairly certain all the Sharpie is coming off.

I do have coarse stones as well, so I'll try moving to those.

The trick in relying on the Sharpie alone, to gauge if the edge is apexed or not, is that the Sharpie can easily come off with inconsistent technique as well. If the held angle isn't stable, and it rocks or pivots a bit, the Sharpie ink WILL quickly be scrubbed off long before the bevels are truly flat and the edge is fully apexed. On very small & thin blades with very narrow bevels already, it takes almost nothing to erase the ink with just an errant stroke or two. And then what's left behind is a rounded 'edge' that's dull and has no ink on it. This is very easy to do on ceramic V-crock sharpeners like the Sharpmaker, because it's lack of aggressiveness in removing a lot of metal means a lot of passes have to be made to create & flatten a new bevel. The more passes and time taken, the more inconsistency and fatigue will creep into the process, and that makes it difficult to make a crisp new edge on any blade.

As mentioned, using something coarser (more aggressive) that creates a new bevel in less strokes/time would be helpful, and looking for the formation of a burr along the full length of the edge will be the TRUE indication the edge is apexed and ready to be refined. I personally LOVE a Fine diamond hone for blades like this (SAKs & similar), because it can create a noticeably flat, new bevel in just a handful of passes (or even a single pass/side on very small, thin blades), with very little pressure exerted. Make sure the burr is formed & flipped to both sides, before moving to finer hones.


David

 

[sldk]

Thanks again for the feedback everyone. Made some real progress tonight using the coarse diamond stones. I think the original bevel was >40deg, so I just had to remove more material.