What constitutes as a mirror finish and other sharpening ?'s

[Robert McNaull]

I have some sharpening woes/questions and general lack of experience (and confidence). Now that I got the disclaimer out of the way, I'll start with my general process. I have hock A2 blades in a No.4 and No. 7, additionally a vintage Stanley blade in my No. 6. Process is a DMT coarse and extra coarse duo for primary bevel setting and flattening purposes. This is then followed by a sigma select II 1200, and a sigma power 8k. Last step is buffing compound on MDF. I get a pretty good edge that will take hair off my arm, but I wouldn't say it shaves hair off my arm. I do apply a micro bevel as well. I have never handled "professionally" sharp tools before so I have a hard time gauging the level of sharpness.

To the questions:

I get a mirror finish on the back but it has a lot of visible scratches that are deeper. Is this normal or do I need to continue to work the back to remove these? Am I finishing with a high enough grit? (my opinion is yes, but based on my level of knowledge I am going to ask).
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The he vintage iron back (top blade) was pretty out of flat and spent about 3 hours and still had a corner not buff out. It has a lot of camber on it and the No.6 just got rehabbed back into service, it was pretty rough shape and the plan is for it to work as a scrub type plane.

Now that I have rambled on I forget what my 2nd question is, guess I'll ask when it comes back to me.

[Derek Cohen]

I get a mirror finish on the back but it has a lot of visible scratches that are deeper. Is this normal or do I need to continue to work the back to remove these? Am I finishing with a high enough grit?

Hi Robert

When re-sharpening, you should not need to go below 1200, and you do need a stone to bridge the gap to the 8000 (probably about 4000-5000) on the back. The scratches are likely due to the too large a jump. Once the back is flat and polished you should not touch it again with a stone under 8000.

Regards from Perth

Derek

[ken hatch]

Just a couple of points: A mirror finish is over rated, what is important is the scratch pattern and that there are no deep scratches left in the cutting edge. Some of the best natural stones will leave a "haze" but the iron may be sharper than one with a gleaming mirror finish. Look for a scratch pattern with no deep scratches. I can't tell for sure but the second photo appears to show a line of reflected light on the cutting edge. The best test for a sharp edge is looking and feeling, it should feel smooth and it shouldn't reflect light.

Keep it simple, it is not difficult, a flat back with no deep scratches, take the bevel to a small wire edge with a medium stone, remove it with your finish stone. Strop if you must.

ken

[Brian Holcombe]

I'll second what Ken and Derek have stated.

When it comes to backs on western blades I really only focus my efforts on the last 1/4"~ looking for a consistent flatness in that area so that the wire edge can be removed with success. Also, it is the mating point with the chip breaker so flatness will contribute to an accurate mating between the breaker and the iron.

I wouldn't use buffing compound on the back of an iron for fear that it will dub the edge…..which is brutal to work out by hand.

I use a dry strop to ensure the wire edge is gone.

[Robert McNaull]

Derek, Ken, Brian, thank you for the responses.

There definitely was a reflection on the edge. I spent a couple hours this morning working the backs on a cheap water stone I had initially bought for chisel sharpening that has a 6k side. This seemed to help along with a lot of time spent on the 8k. I try not to get hung up on the mirror finish but the scratches had me concerned.

To to clarify on my process, once flattened and primary bevel are set I don't go back to the DMT.

Brian, like you said, I try of focus mostly on the last part of the back and at time feel like the very edge is rolled over some. Didn't think about the effect the buffing compound may have on the back and have dropped it from the finishing process.

Blades shaved pine end grain and feel sharp, my curiosity still has me wondering what an "expert" sharp feels like. Kind of like on badger and blade they recommend if you want to learn to use a straight razor to buy one that has been professionally honed so you will know what sharp is supposed to feel like.

[bridger berdel]

Sharp is a moving target. As your skills increase you will find the need for beter edges, right slong with your ability to achieve those edges. Just keep nudging the envelope along.

[Brian Holcombe]

Derek, Ken, Brian, thank you for the responses.

There definitely was a reflection on the edge. I spent a couple hours this morning working the backs on a cheap water stone I had initially bought for chisel sharpening that has a 6k side. This seemed to help along with a lot of time spent on the 8k. I try not to get hung up on the mirror finish but the scratches had me concerned.

To to clarify on my process, once flattened and primary bevel are set I don't go back to the DMT.

Brian, like you said, I try of focus mostly on the last part of the back and at time feel like the very edge is rolled over some. Didn't think about the effect the buffing compound may have on the back and have dropped it from the finishing process.

Blades shaved pine end grain and feel sharp, my curiosity still has me wondering what an "expert" sharp feels like. Kind of like on badger and blade they recommend if you want to learn to use a straight razor to buy one that has been professionally honed so you will know what sharp is supposed to feel like.

Cheers,

That may be the case due to the stones going out of flat as you use them. Do you refresh their flatness regularly in use? I generally work all areas of the stone then re-flatten, in that short period of time it will go out of flat.

Where are you from? maybe you are near someone willing to walk you through their setup.

[Warren Mickley]

Robert, I would be a little worried about the diamond stones. They tend to be harsh and make deep scratches, so there is a possibility that you are just polishing the tops of the ridges and leaving the crevices. Extra time on your finer stones should take care of this. If you carefully rub the back or the bevel in a single distinctive direction, you might be able to see if you have removed all the scratches from the previous stone. If scratches persist from the coarse stones, the edge will be serrated.

In the second picture there is a tiny band of bright light at the very edge of the iron. It is possible that your polishing is not going all the way to the edge; you can see this better than we can.

[steven c newman]

99% of the irons I do....i have YET to spend that Mythical Three Hours on the back of an iron.....

Stanley Vintage ones, Millers Falls Vintage ones, Sargent vintage ones...even Butcher ones. Longest time to mirror polish a back was around.....20. Old iron to see-through shavings? 1/2 hour tops.

[Robert McNaull]

Cheers,

That may be the case due to the stones going out of flat as you use them. Do you refresh their flatness regularly in use? I generally work all areas of the stone then re-flatten, in that short period of time it will go out of flat.

Where are you from? maybe you are near someone willing to walk you through their setup.

Brian - I do refresh pretty regularly, the 1.2k is a pretty hard stone and stays flat, but it loads up quickly so refreshing keeps it cutting, I guess the same goes for the 8k as well.

Warren - I regret using the diamond plate on the backs of the hock blades. First planes, first time flattening and I got impatient and jumped to coarser material. You and Ken have sharp eyes catching the gleam on the edge.

After an hour of working a 6k and back to the 8k, there is some improvement. I am still seeing scratch pattern that is from coarser medium. I probably will end up back on the 1.2k at some point to really try to work out the scratches. I don't expect it to be perfect by an means, but would think that the final set of scratches observed would match the direction of working that was applied by the last stone.


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My shop time has been very sparse the last couple years which coincided with adopting hand tools, having a kid, and working on another degree. I read on here a lot and don't post much and very much enjoy reading and living vicariously through some of the other posters on the forum. Appreciate all of your willingness to share knowledge as well and hope to start spending more time in the shop in the next year.

Best Regards,

Bob

[Brian Holcombe]

That is good that you are refreshing them a lot.

That still looks dubbed to me, are you able to work the back until a wire edge forms?

I liked to make knives as a kid and so one of the hellish steps was polishing them….work the grit in one direction and you form a scratch pattern….follow it up with the next grit at a slightly different angle and you will see when the scratches are truly gone. If the back is flat this will be easy, if it is not flat this will not be easy, IMO.

[Derek Cohen]

There is a light line on the left of the blade. This is either that the back has not been lapped to the edge at these sections, that is, there is a slight hollow there, or that the bevel retains a wire edge that has not been removed. I am not concerned about the scratches - although it would be better without the, of course - but rather the areas mentioned where light reflects. If it is just a wire, then it is telling me that you may be spending too long on the coarser stones and not able to reduce it to remove it later. If it is the back of the blade having hollows at the edge, then there are spots where the blade will cut very coarsely.

This is one of the occasions where the Ruler Trick is so successful. I do not use it, prefering a flat blade back, but it works quickly and avoids issues of diamond stones since there is so little metal to remove.

Regards from Perth

Derek

[Jim Koepke]

All the advice above is solid.


I get a pretty good edge that will take hair off my arm, but I wouldn't say it shaves hair off my arm. I do apply a micro bevel as well. I have never handled "professionally" sharp tools before so I have a hard time gauging the level of sharpness.

What follows is just my 320028.

When one of my edges takes hair off of my arm but doesn't shave hair off of my arm, it is either good enough for what is being done or it is back to the stones. It really depends on what is being done. If it is a scrub plane or being used for rough work, then that degree of sharpness may be enough.

If it is going to pare dovetails or smooth surfaces, then it is back to the stones.

Mostly my edges are kept simple. A few of my blades may get a little camber. Very few of them have intentional secondary or micro bevels. Some of my carving gouges may get a back bevel. Most often that is done to transition an inside bevel to and outside bevel without grinding off the length of the bevel. It doesn't mean all of these other techniques do not work. It means my edges work fine without them. My suggestion at this point is to first get an edge as sharp as you can. Once you get to a satisfactory level of sharpness, then try some of the other techniques.

When a blade is truly sharp, it will remove every hair in its path and you will think it is just rolling over your arm until you see the caterpillar at the edge of the blade and see the smooth skin left behind. Nicks in the edge will pull the hair before cutting it.

Many folks have fine results jumping from 1000 to 8000 stones. I like to have one in between like a 4000.

Some of my blades have seemed to take forever to get the back flat. Some of this may be due to bad technique. It is real easy to rock the blade with fingers worn out from back flattening.

jtk

[Kees Heiden]

When I have an unpolished line just behind the edge on the flat side, I just grind the edge back a bit and rework the bevel. That goes much faster then working more on the flat side of the blade.

I wouldn't worry too much about the scratches. Use the tools, make them dull and sharpen again. This time with just the polishing stones on the flat side. After a few itterations the flat side will look a lot better.

[Mike Brady]

That is a mirror polish, for sure. What I see in your second photo is an edge that does not have that polish, so while you have a shiny blade you don't have a sharp one. I would concentrate now on getting the bevel side to intersect the flat side by honing away away that ragged area (the burr). All of your effort should go into the bevel (or micro-bevel). The polished side is good to go. As you hone the bevel you will soon remove that undesirable area.

[Adam Cruea]

Mirror finishes are sparkly, but what do they mean?

Think about this. . .a ball bearing can have a mirror finish. But it doesn't cut hair, or wood.

Bottom line. . .if it's good enough to cut wood to your satisfaction, then go make some saw dust, shavings, and chips. I've seen too many arguments all over the place about sharpening and razor sharpness and mirror finishes. It's exhausting to read. Old timers back in day didn't sharpen that well because time was money to them, yet they still produced awesome pieces.

At the end of the day, if your chisel/plane/steel cuts wood and does it satisfactorily. . .go with it.

Just my 2 shiny copper coins.

[Robert McNaull]

Thank you all for the responses. This has been a lot of great advice. As many of you have stated the level of sharpness needs are dependent on the plane and application. I have found in most cases my tuning job works well when working the walnut stock but is lacking when working red oak. Takes a lot of force and I get some tearout which I expect the red oak to be tougher, but can tell my blades needs some refinement to improve the plane performance.

Evaluating the back at the edge, it has been rolled over a little. I've worked it to where working the back will most likely not make an improvement , going to have to just wait the edge out with future working of the bevel.

Jim - your description of what shave sharp is what I can get out of some of my chisels, but is not what I get out of my planes.

Thanks again for everyone sharing.

Bob

[Jim Koepke]

Evaluating the back at the edge, it has been rolled over a little. I've worked it to where working the back will most likely not make an improvement , going to have to just wait the edge out with future working of the bevel.

Jim - your description of what shave sharp is what I can get out of some of my chisels, but is not what I get out of my planes.

On plane blades one is more likely to get a small wear bevel forming on the back of the blade. When I notice my blade performance is dropping I try to remember to sharpen right away to avoid increasing the wear bevel. If the wear bevel is gets ahead of me there is a lot of time either grinding with power or by hand on a coarse stone to get back to good metal. Some folks like to use a method called the "ruler trick." It works for many folks but it is not in my repertoire.

A sharp blade and a close setting of the chip breaker should help to alleviate tear out problems.

Google > setting a cap iron < and the first hit should be an article on WoodCentral by David Weaver with more information if you haven't already seen it.

jtk

[Adam Cruea]

On plane blades one is more likely to get a small wear bevel forming on the back of the blade. When I notice my blade performance is dropping I try to remember to sharpen right away to avoid increasing the wear bevel. If the wear bevel is gets ahead of me there is a lot of time either grinding with power or by hand on a coarse stone to get back to good metal. Some folks like to use a method called the "ruler trick." It works for many folks but it is not in my repertoire.

A sharp blade and a close setting of the chip breaker should help to alleviate tear out problems.

Google > setting a cap iron < and the first hit should be an article on WoodCentral by David Weaver with more information if you haven't already seen it.

jtk

Is Mr. Weaver still around?

[ian maybury]

+1 that using a coarse diamond (especially a fresh one that hasn't been run in) has the potential to leave very deep scratches. Finer diamonds (as on say a well run in 180 or finer lapidary disc) don't in my experience scratch so deeply that the marks don't quickly polish out on a 1,000 grit waterstone.

The other issue that can lead to scratching is not being scrupulously careful about washing the iron on moving from stone grit to stone grit - it's very easy to carry occasional coarse grits over on to the finer stones where they will cause scratching. It eventually becomes a 'hygiene' or contamination everywhere problem if the sharpening area isn't kept scrupulously clean.

It's hard to overemphasise how critical stone flatness and careful blade handling are so far as avoiding dubbing is concerned. It's not for example a given that a new diamond plate is flat enough to avoid issues (especially while flattening the back), it's critical to follow a regime like the Charlesworth one to spread wear evenly over the stone and to flatten it as frequently as he says, and even a very tiny error in terms of tipping up or misplacing an iron can do enough harm (especially immediately behind the edge to need a huge amount of work to flatten the back again. Even a too heavy build up of slurry (a little may be is helpful) may lift a blade unevenly enough to cause problems.

Flatness is a kind of a catch 22 problem. If you have truly flat stone (the result of flattening carefully with a truly flat diamond plate or similar) the give away is that it should almost instantly cut all over (create a scratch pattern over pretty much the entire surface being worked) or the iron is likely not flat - or vice versa. If nothing is flat (the diamond plate used for flattening, the stone or the back of the iron) then it's back to basics. Maybe start by checking the diamond plate used for flattening - at minimum with an accurate straight edge and a light. (which may still miss a twist) Best of all a small (now very cheap) granite surface plate with a very light film of blue will show up high points. Once you have a flat plate then it becomes possible to make the waterstones flat and keep them that way while you work.

As Jim a heavily used blade let go too far before re-sharpening may have enough of a wear bevel (to varying degrees on both sides of the edge) to need plenty of cutting back on the bevel side to remove (there's a few pieces on the web about how wear bevels and their less than complete removal can mess up sharpening, prevent removal of wire edges and result in failure to achieve the required two polished facets meeting at the required angle) - it's to my way of thinking probably easier to do it on that side as it can be very labour intensive via back flattening.

As the others the Charlesworth ruler trick tends to be effective for many. It'll remove any slight dubbing or wear bevel on the flat back very quickly, and is just that bit less sensitive in terms of needing a precisely flat stone.

The alternative is to head for methods that use heavy stropping and the like to bring up the edge - they likewise are much less dependent on the blade and the edge and the stone being perfectly straight and flat...

[Jim Koepke]

it's critical to follow a regime like the Charlesworth one to spread wear evenly over the stone and to flatten it as frequently as he says, and even a very tiny error in terms of tipping up or misplacing an iron can do enough harm (especially immediately behind the edge to need a huge amount of work to flatten the back again. Even a too heavy build up of slurry (a little may be is helpful) may lift a blade unevenly enough to cause problems.

If one is aiming for a perfect blade with flawless mirrors on both sides, then yes there is a similar level of perfection that must also exist in the sharpening system.

If one is merely attempting to get great results smoothing, chopping, shaping and pairing wood, then a few miniscule scratches in the polished bevel of a chisel or plane blade are not going to be a big problem.

At the edge there doesn't even have to be a long bevel. This is one of the advantages of a secondary or micro bevel.

The real problem with stone wear is when you hone a wide blade and it polishes at the edges but not the center or similar anomalies. Then there is no more putting off the work needed to flatten the stone(s).

The lesser wear of oilstones is something to be appreciated.

jtk

[ian maybury]

Pardon my perhaps coming across like a zealot, as my serious learning on topic only came last year after a lifetime of 'getting by' sharpening with a switch to using watersones - to work up a set of Japanese chisels and some planes. But exactly.

There's none so zealous as the newly converted as they used to say, but sorting a technique that works and being religious about sticking to it really matters. The wonder perhaps fades for the older hands, because they have long sorted a routine that works without having to think too much about it, but it's scary how little of an out of flatness problem it takes to mess up.

Sharpening single bevel as before is even more picky about flatness - but the ruler trick and micro bevels in effect take advantage of the fact that an effective cutting edge typically only needs short bevels. Hard stropping is likely even less sensitive i suspect given the spring in the leather (i've only used a fibre polishing wheel for finishing), requiring only that the edge be got pretty close on the stone.

One conclusion is that it's best to always be ahead of the posse with stone flattening. To use a pre-emptive routine. The risk being that by the time it gets bad enough to produce obvious symptoms the harm is likely done.

[Brian Holcombe]

I use natural stones for that reason, constant re-flattening of finish stones was driving me mad. They require touch up but not nearly as often, so I generally flatten before I start using them and then after each part of the blade. Touch up involves only a 1200 diamond plate, so there is not alot of stone being wasted during each use.

I have, so far (hehe) a Shinden suita (10-15,000 grit) and a Nakayama Asagi (20-30,000 grit). So I take a normal routine of diamonds, 1000, 3000, 8000 water stones, then natural stones. Even with very common flattening of the waterstones some out of flatness will show in the final polishing on the natural stones.

For maintenance sharpening I can simply return to the finish stones unless I get chips in an edge during use.

[ian maybury]

The essential issue i guess if dealing with especially large flat areas (backs of blades, single bevels) being that even a few microns of out of flatness will likely result in a surface not immediately texturing/cutting/showing all over - whether it's the stone or the iron that is the problem.

It seems to me Brian that in a sense there's two steps to the sharpening game. First we have to figure out how to get a sharp edge, then it becomes a matter of experimenting to make the process a bit more time/mess/whatever effective. I'm at the point where i'm getting good edges, but haven't really started to tune the process yet. The stages may overlap/mix together a bit...

[Brian Holcombe]

The extreme flatness is troubling for something where you reeeeeeaally want to be precise, such as prepping for kezurou-kai planing competition, but for everyday woodworking I will do two things to get quick and dirty.....tiny microbevel on both sides (tiny, like 3 swipes) and refine with the bare strop. I will cheat more and more as I rehone until it becomes tedious, then I will drop back down to 1000 and refresh everything. Very tiny mircrobevels will disappear at this point, so dont go nuts.

[Andrew Pitonyak]

Where do you live Robert? If you live near the middle of Ohio, I am happy to show you what I call sharp... and then either you can laugh at my hack job or I can laugh at yours.... and then we can make it so that we both have equally sharp tools.

I am in the process of setting up one of the three planes mentioned here (http://www.sawmillcreek.org/showthread.php?234851-Identifying-hand-plane-made-in-India&p=2461215)

The back is resistant to being flat, one corner is very low :mad:

I have put about 2.5 hours into it so far, but I think that I have poor technique that is improving for doing this part. Would have been faster if I had started with say 120 grit sandpaper rather than 400.

[Robert McNaull]

I made some progress over the last couple weeks. I spent some time working my No. 7 hock iron and my No.6 vintage iron with some real success. I spent some time on the backs and got a image that matches pretty well what Brian was kind enough to share in his cabinet thread. Reworked the bevels, found the vintage iron really pleasant to work. First few passes with the planes when I did this last week were not very good. Pushed hard, left a pretty clean surface but not as nice as I would hope from a fresh iron, given this is red oak, but expect better. So I went back to the shop tonight and spent some time fettling the plane and rediscovered some things that I knew but have forgotten, suppose that's what a year of down time will do.

- Set the blade and centered it up as best as possible
- Advance the iron making strokes until a shaving is made
- when a shaving is made, tap the iron on the side to center the shaving (I use whatever is handy, screwdriver handle tonight)
- continue to advance the iron until a well centered, close to full width shaving is produced

What a world of difference and the vintage iron was cutting the best of the two. Produced a surface reminding why I like handplaning.

Some other improvements: I have a heavy MDF bench with no vices and no plane stops. Last Saturday I drilled some 3/4" holes and shoved a 1 1/2" dowel rod in my metal lath and turned out a couple plane stops. I had been using a 3/8" board clamped across the end of my bench, adding a couple good hard stops really make a difference when pushing a plane.


Andrew - I am located in central Iowa, I am originally from north central Ohio and make it there about 3 times a year.

I know some of these items are straying from the title so I apologize, but these things don't merit a new thread. Thanks for reading.

[Brian Holcombe]

Gad to hear it's working out! Nothing more enjoyable than nice smooth shavings :D

You can do a lot with some planing stops and battens.

[steven c newman]

I think I am getting the hang of rehabbing these things....
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This came in the mail today...Hour and a half or so later...
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Edge is honed to 2.5K grit. Angle is about 25 degrees or so. Back is flat, sole is flat enough. replaced those cheap plastic handles with real wood ones. Seems to be a Stanley #4 T-20. Made a lot of this stuff..
320793
Might just do...

[Andrew Pitonyak]

So I went back to the shop tonight and spent some time fettling the plane and rediscovered some things that I knew but have forgotten, suppose that's what a year of down time will do.
Andrew - I am located in central Iowa, I am originally from north central Ohio and make it there about 3 times a year.

I know some of these items are straying from the title so I apologize, but these things don't merit a new thread. Thanks for reading.

Sounds like you are getting the hang of it.... If you are near Columbus on a visit and want to do some sharpening, let me know. I don't make it to Iowa often; only been there once. Glad to hear it seems to be working out. :D

[Andrew Pitonyak]

You do very well Steve. Very impressive. Where did you get the real wood handles?

[steven c newman]

An old Dunlap plane. Switched just the handles. Dunlap may be going up for sale, sooooo might as well use the "good" parts.


Have been known to make a few, from time to time....