Sharpening/Sharpie method question

[Shmohawk]

I've been attempting to improve my extremely limited freehand sharpening skills and have a question.
On this one knife (which may not have been the best to practice on as the bevels where quite uneven) I cant seem to reach the apex on one side.
Attempting to sharpen/reprofile it to 15 dps on a cheap 200 grit diamond plate.
I used a sharpie and, after checking with a loupe, its completely gone all the way to the apex but I can see that the new scratch pattern is not reaching the apex.
I reapplied the sharpie and kept on going.
Same result.
I then resharpied it again and tried on the Sharpmaker CBN rods at the same 15 dps in to see if my angle was off when free handing and got the same result.
If the sharpie is gone to the apex doesn't that mean that I'm hitting the apex?
How could the the sharpie be removed completely from the bevel all the way to the apex but the scratch pattern be different?
What am I doing wrong/not understanding?

[Guts]

Could be that the angle is slightly changing between your leading and trailing strokes, hence the main scratch pattern not really hitting the apex but still removing the sharpie. You might try only edge leading or only edge trailing strokes and see if you experience the same thing.

[Shmohawk]

Could be that the angle is slightly changing between your leading and trailing strokes, hence the main scratch pattern not really hitting the apex but still removing the sharpie. You might try only edge leading or only edge trailing strokes and see if you experience the same thing.

I started off with edge leading only for a long while. Slow, steady and light. Then when I saw that the scratch pattern wasn't making anymore progress toward the apex I thought maybe it was slightly convexed or was double beveled and I needed to remove more steel so I switched to leading and trailing which didn't change anything.
Either way I don't understand how the sharpie can be coming off completely but the scratch pattern isn't progressing to the apex.

[Bemo]

Question (with all due respect to the anti-burr contingent) but have you been able to form a burr?

[Shmohawk]

Question (with all due respect to the anti-burr contingent) but have you been able to form a burr?

My experience with burr formation is very limited. Until recently I've primarily used the Sharpmaker with alternating strokes. I do believe I formed a burr when sharpening the other side but it doesn't seem to be there anymore and I don't seem to be forming one when sharpening the problematic side.

[RustyIron]

I used a sharpie and, after checking with a loupe, its completely gone all the way to the apex but I can see that the new scratch pattern is not reaching the apex.

The "Sharpie Method" has value, as long as you understand its limitations. I suspect that there is a small amount of swarf being dragged along, which is rubbing off the ink but not doing anything to sharpen the blade. Just keep going, and believe what you see with your eyes through the loupe.

[kennbr34]

Are you coloring in the entire bevel with the sharpie? I used to have this problem when I did it that way, and I think it has something to do with either the layer of ink becoming too thick, or the gumminess of it collecting too much swarf. Either way you end up with the sharpie at the apex being rubbed off, but the metal underneath not really being touched.

What I do now instead is draw little lines perpendicular to the edge. I do about one line every 1/4" or 1/2" so that the blade looks like it has tiger stripes. Doing it that way, I can be sure I haven't left a coat of ink too thick, and leave much less ink on the blade for swarf to stick to.

[Shmohawk]

Are you coloring in the entire bevel with the sharpie? I used to have this problem when I did it that way, and I think it has something to do with either the layer of ink becoming too thick, or the gumminess of it collecting too much swarf. Either way you end up with the sharpie at the apex being rubbed off, but the metal underneath not really being touched.

What I do now instead is draw little lines perpendicular to the edge. I do about one line every 1/4" or 1/2" so that the blade looks like it has tiger stripes. Doing it that way, I can be sure I haven't left a coat of ink too thick, and leave much less ink on the blade for swarf to stick to.

Yes, I've been coloring the entire bevel.
Will try the stripes.
Thank you for the tip.

[Rusty_Shackelford]

Interesting suggestion, Kennbr34. I’ve been having the exact same issue. I’ll give the tiger stripes a try!