Setting a Bevel, need some guidelines

[Mjdavid]

I’m curious to know what moderately skilled people do to their knives on 400-500 grit stones.
The reason for my question is that I like to experiment for the sake of learning. For instance, I wanted to see if I could put a “new” bevel on my Mazaki 180mm petty so I started on my Chosera 400. My approach was simple, establish a familiar angle and carefully hold that angle while making only enough strokes (at moderate pressure) to establish a visible new bevel. I didn’t really pay attention to getting a bur at first pass since the new edge was visible (and it’s 400 grit and it cuts predictably) before switching sides and doing the same thing. I went relatively slowly so I could concentrate on angle control. I repeated this cycle a couple more times with progressively lighter pressure then finished with very light stropping strokes.
My questions are: How do you judge when to move up the progression? How sharp should this edge feel before jumping to my 1000 grit stone? How much time should I spend on this 400 grit stone? Also, what do people do with a new gyuto to ‘put their own edge’ on it...steepen the angle?

 

[Benuser]

Just how I do with a new knife: I start by painting the very edge on both sides with a marker. So I'm sure not to overlook a possible micro-bevel.
I start on the right side at the lowest possible angle I feel comfortable with. With a loupe I verify where I do abrade steel by looking at the scratch pattern. Little by little I raise the spine. At some moment all ink is gone along the entire edge. At that same moment you feel a clear burr at the other side: it feels rough. Make sure the burr is clearly present along the entire edge. Quite often the heel area is thicker and require some more work.
You may start exactly the same at the other side. Or put a straight edge on the left side at a noticeably higher angle without working first the area behind it. That is generally how I do with a brand new knife, to make sure the weak edge OOTB has gone. As the blade is asymmetric and the edge off-centered to the left, a higher angle makes sense to balance friction on both sides and limit clockwise steering.
Anyway, you raise a new burr at the right side. Again, verify the scratch pattern. If you use a much higher angle on the left side, the burr is like to appear after only a few strokes.
You may reduce the burr by flipping sides and reduce pressure as much as you can. Don't expect it to disappear completely though.
If you can't reduce the burr any further and it only flip sides, it's time to go on the next stone. As the bevels have already things will go very fast now. I don't strop and deburr on the Chosera 400. I do that first on the next stone. With edge trailing strokes (stropping) you dramatically reduce the remaining burr. Deburring takes place by making very light strokes along the entire edge, a few per side. Test with very fine cigarette paper. If it cuts smoothly and silently the burr has gone.

 

[vicv]

Myself I wouldn't stop with the 400 grit stone until a full burr is formed otherwise the bevel isn't done yet. Also I completely remove the burr before proceeding to the next stone

 

[Benuser]

Also I completely remove the burr before proceeding to the next stone

I'm afraid you can't completely remove the burr with a 400-stone. You can reduce it. You go to the next stone if you can't reduce it any further and it only flips sides.

 

[vicv]

It is possible. I either whack the board to see if any wire edge appears or something I learned from Mr Martell and put the edge into a leather belt on my belt sander. Usually a couple very light high angle passes does the job. I've done it off a 100 grit stone

 

[HRC_64]

The threshold for moving up to 1K is simply being able to form the burr at 1K ... consistently, without too much time/effort...more time effort tends to lead to more incosistent bevels, so the 400/500 is used for fewer pasess as well as faster overall time.

I’m curious to know what moderately skilled people do to their knives on 400-500 grit stones.

I didn’t really pay attention to getting a burr...

not forming a burr and flipping sides at just the correct time is absolutely expert level technique, not beginner or intermediate ... so if you're asking "what's wrong" ... I would say...this is the likely problem.

Just my $0.02

 

[Mjdavid]

I’m not sure there is a problem...I’m just comparing notes so to speak. All I’m saying is that I spent a very few strokes on the 400 to establish a clean visible bevel on both sides before moving up to the 1k. I was just wondering how others judge when it’s time to move up? How sharp should a 400 grit edge be?

 

[HRC_64]

This might be semantics, but there is one defintion of "sharp", which is that there is a clean apex. You can then do a coupel things, like "narrow" the apex (lower the angle), and "refine the apex" (clean/deburr, then polish, higher grits etc).

But it takes a masterful skill to create a clean apex on a 400 stone without burr formation or removal.

Which means in general unless you are confident in that level of skill,
you're probably not at a clean apex when you leave the 400.

So there is (possibly) no sharpness coming off the 400, just an approximation of an edge,
and then you go to the 1K to do a proper sharpening.

Whether or not any of this is good or bad really depends.

The general practice of burr formation is that it allows you to measure through tactile feedback for "even" ness of the burr, which keeps the edge centered in the core steel (amongst other things). Thats in the left to right plane...

It also should keep the angel consistent or on target from front to back of the edge, along the length
so you are giving up all of this if you don't form a bur...any mistakes the 400 creates
then carries over to the 1K.

Skill and patience will make almost any sequence ultimately work, its just a question
of optimizing your own time and workflow.

But in general the concept of a 400/500 is to quickly set or re-set a clean bevel,
to the apex, and form a burr, so you don't need to do any of this geometry modification
on the 1K which is slower and will take more strokes and time and create more chances for error.

 

[Maccne0718]

I usually move up when I can cut paper

 

[Mjdavid]

But in general the concept of a 400/500 is to quickly set or re-set a clean bevel,
to the apex, and form a burr, so you don't need to do any of this geometry modification
on the 1K which is slower and will take more strokes and time and create more chances for error.

Gotcha, thanks.