Is This Typical for 8k and 12k?

[duke762]

When sharpening on my Shapton Pro 5k my apex is super clean, but after the 8k and 12k Shapton Pro's, I pick up some apex sparkles. I tried 6 laps on the 8k and 10 on the 12k and still seeing sparkles. I assume it's the beginning of a fin edge. With my low lap count, could pressure be the culprit?

It's a non issue, just want to make sure I'm getting the most out of these 2 stones before moving on.

 

[JPO]

I would say pressure, and/or too much time at 8k and 12k.
You should not need to spend allot of time on these finer stones if your ground work is good.
After 5k you should only need 10 to 15 strokes and maybe even less on the 12k.

 

[H Brad Boonshaft]

Yup, pressure and or time.

Not an issue. Joint the edge with one light stroke on the face of the stone and reset the edge. It should not take more than 10-15 laps. You are only removing microns of steel by jointing, but you are making the edge straight, then you only need to bring the bevels back to meeting at an edge that is already straight.

Once the bevels are flat and in the correct bevel angle it does not take many laps to bring them back to meeting. Do just enough laps to get them to meet, doing any more on that stone will not make the edge keener or smoother.

Too many laps can make the edge thin and weak.

 

[Gamma]

Almost anything along the edge can reflect light. Just shave with it. If it shaves well, it's fine.

 

[psfred]

Make sure you don't have concave areas on those high grit stone -- same effect as lifting the spine off the stone.