I've got a Camillus Camlite and I've never sharpened a knife before (only straight razors) so thought it'd be a similar process. I had to work on a lower grit to get an edge as I had blunt it to try sharpening it from scratch. I think I was at about 15 degrees and sharpended up to 2k then on to a pasted strop. While it's sharp and I can cut most things pretty well, including wood, it doesn't cut like I've seen a whittling knife cut.
I'm not sure if it's the sycamore posing a problem or the blade maybe needs taking back a few steps then working back up to a higher grit?
You say you blunted it to sharpen from scratch. Did you fully apex it with your first, coarsest stone? If not, then your finer stones were just polishing the shoulders.
Perhaps the Sharpie trick would help you see where your abrasives were abrading in relation to the exact edge.
Parker
Knife sharpening is quite a bit different from straight razor honing. With a knife's thicker edge, you have to make sure you develop a burr along the entire length of the blade, on both sides, before moving on from the coarsest stone. Then you can move on to higher grit stones, but ultimately sharpness will be determined by how well you deburr the edge. Most recommend trying to deburr as much as possible on your last stone, using very light stropping strokes. Then proceed to your strop or strops of choice.
I believe the knife you mention is less than a $20 knife in 440 at 52HRC (and who knows if it 440 A, B, C ...).
No comments meant to be derogatory, but a "whittling knife is going to be optimized for the task much better than a generic hollow ground pocketknife (and most likely sharpened to less than 15dps).
15dps is where I typically start a new knife relationship, and generally by 220grit the edge can shave arm hair. Progressing higher in grit yields little (time investment vs return value) in actual cutting performance other than edge stability, increased push-cutting vs. slicing ability, smoothness in the cut, cleaner cuts, etc. Make sure entire edge (ricasso to tip is fully apexed and of equal sharpness) after first sharpening grit.
catspa above - I am guessing could be correct (edge not cleanly and fully apexed before moving to higher grits. I would suggest NOT fully apexing using anything more coarse than 200-300 grit as you can sometimes damage and edge you have been working on (especially at 15dps and lower).
3D Anvil above - I am guessing also may have the answer related to residual bur. A bur (while very sharp initially) can hold on for a while in actual use, possibly even move back and forth a few times before breaking off and leaving a very blunted edge. Be sure to test sharpness from both sides of the blade to determine if a residual bur is leaving the edge sharper/duller on one side than the other of the blade.
In current situation, I would highly suggest eliminating the urge to go to 2k and strop (wasted time it sounds), and test the knife in the media of your choice after 400-600 grit final with a deburring process at each & every stone progression. Polishing a pair of bevels that do not form a clean crisp apex is for pocket jewelry vs. a tool. Additionally, polishing anything is potential for rounding transitions.
I do not think the wood you are cutting to be the issue, as a 770lbf Janka hardness, Sycamore is in the moderate class of hardwood category. It is a little harder than Douglas Fir (semi common framing wood in residential construction) and a little softer than Eastern Red Cedar. If you have the knife and a flat section of that wood, lay the primary bevel flat on the wood and raise the spine till the edge just begins to bite on a forward stroke then flip the knife over and do exact same using opposite side edge. Note any difference in the way the knife bites as reflective of left vs right edge being different (as in side with bur will bite more easily and sooner).
* Link Janka Hardness comparisons:
Janka Hardness
