sharpening question !

[charles mathieu]

I'm wondering how you guys resharpen your chisels and handplane blades. I always put a microbevel on my blades and when they get dull, I only resharpen the microbevel and then remove the burr on the back. I'm thinking that at some point I'm gonna have to resharpen the primary bevel no ? How often should one completely resharpen the whole thing ? My understanding is that each time I redo the microbevel, it ends up getting bigger and bigger

[Derek Cohen]

Charles, when the secondary bevel gets too large, it is time to buy another chisel.

Alternatively, you could grind a new primary bevel :)

Since it appears that you are using a honing guide, either flat with a belt sander or hollow with a bench grinder. Do you have either?

Regards from Perth

Derek

[Warren Mickley]

I always sharpen full bevel at every sharpening. I think that is the most consistent way. Chisels with hollow grind or micro bevel or secondary bevel or convex bevel don't work as well as flat bevel chisels.

[charles mathieu]

no I sharpen free handed only. I do have a belt sander and a cheap grinder though.

[charles mathieu]

wow you do a complete resharpening each time ? I'm using a bevel up low angle jack and it takes a while to grind a primary bevel on those even by using my 400 wet stone

[Warren Mickley]

If you do a secondary bevel it takes quite a while to get back to erase that secondary bevel. I spend about 70 seconds sharpening a chisel; about 90 sharpening a plane iron.

[Anuj Prateek]

I use DMT Diamond stones and a Shapton to sharpen my chisels and plane iron. I tried hand held but did not get good results so I switched to Lee Valley honing guide. To flatten backs I use Sandpaper on granite surface plate.

Originally I used to create a secondary bevel but it did not help with re-sharpening - repeatability with guide was poor. So, I switched to just one primary bevel. Now that's a pain. With poor repeatability, it's practically regrinding the whole bevel. Anyway I did it for a year.

Recently, I bought a Worksharp. After I am done with primary bevel (at 6k sandpaper), I move to Shapton (12k). I take 10-20 swipes at higher angle (2°-5°) using honing guide on Shapton and I am done. I think it creates a microbevel (?) or a tiny secondary bevel, unlike the 1/32" secondary bevel I used to previously create. Whole process takes just a few minutes. If I was good with hands or jig was repeatable then I guess I would get same results with stones as well.

Downsides:

Previously I used to polish the whole bevel. Now the primary bevel is left at 6k. I still get an edge sharp enough to shave hair but the bevel does not look as nice.

Right now I am using the sharpening port so am limited to 2". The 400 grit paper in the port screws the polish on back, so that's additional 5-10 min work to restore it - don't know if it's really required. This limit and problem will go away once I make a platform to do above wheel sharpening using guide.

I continue to sharpen No. 7 plane blade using guide and stones and it continues to be a pain.

PS: This is all based on 1 year experience so take with a grain of salt.

[Michael Fross]

I always sharpen full bevel at every sharpening. I think that is the most consistent way. Chisels with hollow grind or micro bevel or secondary bevel or convex bevel don't work as well as flat bevel chisels.

Hello Warren. Can you elaborate a bit more on this? In my experience there is zero difference in full bevel or micro-bevel sharpening. Only the very tip touches the wood.

Michael

[Tom M King]

I also do single bevel sharpening, but for yet again, another reason. I have two helpers that are hopeless by hand, but that's not why I hired them, so don't expect them to learn. For example, I can say, "sharpen this to 25 degrees, and they can do it." I had to come up with a system that is exactly repeatable, that anyone can get good results with.

I made setting jigs that can be used with any jig, and are always exactly repeatable. Main bevels are ground a little sharper than the final cutting bevel angle, and the sharp bevel takes over more of the bevel with each sharpening. Cutters never touch a grinder unless there is some damage to an edge. We do have a number of chisels, and plane irons where the honed bevel has taken over the whole main bevel, but we don't worry about that, one way, or the other.

If we did microbevels, they would always be chasing something that they couldn't find. This is simple, and easy to follow.

There are many ways to accomplish a sharp cutting edge, and no way is the absolute only "right" way. Find something that works for you, and that's all you need.

[lowell holmes]

When I have to do a serious sharpening on plane irons, I use a honing guide and a diamond hone. I take it to absolute sharp and then hone the back side of the iron to
get rid of a burr on the bevel. I do the same with chisels.

[Warren Mickley]

Yes, it is not as straight forward a picture as you paint, Michael. Maybe if you hold the chisel perpendicular to the work and scrape, only the tip touches the wood. Otherwise the bevel touches the wood if we chop any more than a tiny amount into the wood. And for some operations we ride the bevel, which doesn't work very well if the bevel is not flat. And a chisel which is a straight wedge will produce a nice spreading of the tissue for easier exit and less abuse to the edge. Wiggling the chisel to effect extraction is abusive to the edge. There are a lot of subtle things that add up to give the edge more or less longevity.

I hope you can visualize some of these suggestions; a complete analysis would be quite complicated. I can only give hints as to what is going on. Some have focused on finding a chisel that can take a lot of abuse; I have found it more helpful to focus on clean technique to promote speed and edge life. A straight wedge shape facilitates that clean technique.

[Mike Henderson]

I establish a primary bevel of 25 degrees on a WorkSharp and then put a secondary bevel on with my water stones. When the secondary bevel gets too long, I go back to the WorkSharp and grind the primary bevel back again. Pretty quick and easy.

I do all my chisels that way, including Japanese chisels. I put the secondary bevel on by hand (no jig) so I can adjust the angle of the secondary to suit my work.

Mike

[Derek Cohen]

wow you do a complete resharpening each time ? I'm using a bevel up low angle jack and it takes a while to grind a primary bevel on those even by using my 400 wet stone

Charles, I have a different system of sharpening to that of Warren since the tools we use are different. I must emphasise that the issue here is “different tools”, and that it is horses for courses. Where we share similar tools, I do the same as he. An example of this is in laminated Japanese chisel blades, where I home them on the full face. You will find past posts where I have argued that they may be hollow ground, but this is not my norm.

Modern blades tend to be thicker and use steel that is more abrasion resistant than high carbon types. These include A2 and PM-V11. Contrast this with laminated blades, such as Japanese, where there is only a thin hard cutting layer.

It is notably the BU planes that really require a different sharpening strategy (and especially why I am replying to you). First off, the blades from LN and LV are typically 3/16” thick. Secondly, all planes (BU and BD) need to camber the blades to avoid tracks when planing face grain. Thirdly, high cutting angles (I only use a bevel of 50 degrees) are needed for BU planes to avoid tearout with interlocked wood. The net result of attempting to freehand a camber on a 50 degree bevel on a thick abrasion-resistant steel scared most BU users away from doing so for many years. Some still have not got the message that there is a simple method to do so.

1. To camber a high angle BU blade you always use a honing guide. I freehand all my other blades - chisels and BD plane blades (on a hollow grind) - but BU plane blades need a guide to get the bevel angle correct.

2. Only ever use a 25 degree primary bevel. Never hone a full angle bevel, such as 50 degrees. Instead, add the 50 degrees as a secondary micro bevel to the 25 degree primary bevel. Add your camber while doing this. There is significantly less steel to remove this way. Honing and cambering BU plane blades can be a quick process.

Article I wrote many years ago: http://www.inthewoodshop.com/WoodworkTechniques/TheSecretToCamberinBUPlaneBlades.html

My system for BD plane blades and all Western chisels is to freehand on a hollow. This creates a coplanar microbevel. An analogy is that this is similar to using a Japanese blade, which is hollowed (relieved) on the back to speed up honing hard steel. Working on the full hollow, rather than freehand creating a secondary micro bevel (tipping the blade), ensures repeatability of the cutting angle.

The quality of the hollow determines the speed at which you can hone. As full a hollow as possible - that is, as close to the edge as you can get without burning steel - reduces the steel to hone and speeds sharpening time, especially with abrasion-resistant steels. The two systems I recommend are the water-cooled Tormek and, better still, a 180 grit CBN wheel on a half-speed bench grinder. The CBN system is fast but also runs cool.

With this system it is possible to hone the first grind with a 5000 grit waterstone, and then proceed to the final polishing stone. I only need 2 or 3 swipes with each. That is fast. As the micro bevel grows, and it does this slowly, add in a 1000 grit stone. I generally re-sharpen about 5 times before touching up the hollow. Note that steel is removed from the hollow and not the length of the blade.

Article about this system: http://www.inthewoodshop.com/WoodworkTechniques/UltimateGrindingSharpeningSetUp.html

Regards from Perth

Derek

[Stewie Simpson]

. As the micro bevel grows, and it does this slowly, add in a 1000 grit stone. I generally re-sharpen about 5 times before touching up the hollow.

Derek; out of curiosity, why the need to return to the grinder after only 6 sharpening's.

Stewie;

[Derek Cohen]

Derek; out of curiosity, why the need to return to the grinder after only 6 sharpening's.

Stewie;Stewie, I'm guessing here. I do not keep track of this. It could be twice or three times as much. The point I wanted to make was that reducing the amount of hard steel increases the speed of honing thicker, harder blades.

The relevance is this: adding a secondary micro bevel, whether this is created with a honing guide or freehand, will eventually necessitate that the primary bevel is restored by a fresh grind. The problem with the freehand secondary is maintaining the bevel angle. This is not as critical for bevel down plane blades, but can become a problem for BU plane blades and chisels. Freehand honing the latter on a hollow is self jigging, and this enables one to both retain the bevel angle as well as speed through sharpening. BU sharpening needs to be approached differently. That was my message.

Regards from Perth

Derek

[Jim Koepke]

It may be my good fortune to not have the ability to hollow grind my edges.

Over time this has influenced my efforts to maintain a flat bevel.

In the past most of my irons needed to be reground due to sloppy maintenance causing the bevel to wander from being totally flat. Another way of saying this is an unwanted secondary bevel was created. The discipline required to maintain a flat bevel has improved my freehand skill.

Now mention of cutting technique having an effect on edge retention has me thinking about how to prolong edge life during use.

jtk

[Warren Mickley]

IThe discipline required to maintain a flat bevel has improved my freehand skill.

Now mention of cutting technique having an effect on edge retention has me thinking about how to prolong edge life during use.

jtk

Here is an example of technique affecting longevity.

I watched a video of a fellow cutting dovetail sockets in a cherry drawer fronts. He had removed the bulk of the material and was making his last cuts.

The drawer front was vertical in the vise and he was pairing horizontally to the gauge line. At the end of every cut he would flick out the waste, scraping the chisel against the back wall of the socket. You could hear the scraping on the video with every cut he made. This kind of scraping is hard on a sharp edge, much harder than the paring end grain.

In addition, he had the board seven or eight inches above the vise, so that it was not so secure. You could see it shudder with each cut, also rough on the edge. And the bench was wobbly also (may not have been his bench). There was nothing wrong with the sockets he produced, but he could have been working with sharper chisels and had better edge retention with cleaner technique.

[James Pallas]

Here is an example of technique affecting longevity.

I watched a video of a fellow cutting dovetail sockets in a cherry drawer fronts. He had removed the bulk of the material and was making his last cuts.

The drawer front was vertical in the vise and he was pairing horizontally to the gauge line. At the end of every cut he would flick out the waste, scraping the chisel against the back wall of the socket. You could hear the scraping on the video with every cut he made. This kind of scraping is hard on a sharp edge, much harder than the paring end grain.

In addition, he had the board seven or eight inches above the vise, so that it was not so secure. You could see it shudder with each cut, also rough on the edge. And the bench was wobbly also (may not have been his bench). There was nothing wrong with the sockets he produced, but he could have been working with sharper chisels and had better edge retention with cleaner technique.

Warren, Would you tell us where this video is located so we can see how not to this task?
Jim

[Jim Koepke]

Here is an example of technique affecting longevity.

Thanks Warren.

jtk

[Mel Fulks]

Warren, that chisel technique thing makes a lot of sense. Good example of the stuff learned in apprenticeship that might
not occur to many on their own. Thanks

[Warren Mickley]

Warren, Would you tell us where this video is located so we can see how not to this task?
Jim

I purposely omitted the name of the guy who was doing the dovetailing. It is not Sellers, but the guy has some following and people would be upset that someone dared criticize him.

Mel, yes this is something that you can point out to an apprentice or student. One historic picture that I like shows a row of benches of workers all facing the same direction. Except for one bench. The young boy's bench is turned around so that he and the master are face to face.

Here is another video of another guy who is a little careless with his chisel edge but otherwise skilled. Check out the flicking at the end of the cuts around 8:40.
https://www.youtube.com/watch?v=HPQK_EGyXbY

[David Eisenhauer]

Food for thought about chisel technique. Thanks Warren.

[Robert Engel]

I recommend hollow grinding. You will periodically have to redress it, but especially on chisels IMO the chisel performs a little better because there isn't as much wedge effect.

[Jim Koepke]

I recommend hollow grinding. You will periodically have to redress it, but especially on chisels IMO the chisel performs a little better because there isn't as much wedge effect.

With something like a mortise chisel, one might want to have a 'wedge effect.'

Hollow grinding has an advantage when performing freehand sharpening. It gives a positive feel when the blade is in contact with the sharpening media.

jtk

[Robert Engel]

With something like a mortise chisel, one might want to have a 'wedge effect.'

Hollow grinding has an advantage when performing freehand sharpening. It gives a positive feel when the blade is in contact with the sharpening media.

jtk

True!! I forgot some people don't sharpen freehand :rolleyes:

[Jim Koepke]

True!! I forgot some people don't sharpen freehand :rolleyes:

My sharpening is primarily freehand. It does take a lot of practice to keep a flat bevel flat.

Another revelation was my experience with water stones taught me how to better use oilstones. For some reason oilstones never seemed to work for me. After a few years of using water stones it surprised me one time when trying to sharpen a gouge how well my oilstones would all of a sudden work.

jtk

[Jason Kamery]

I freehand a secondary bevel on my planes and chisels on waterstones. Depending on how much woodworking I do during the week/weekend, I probably get back to the primary bevel (still on stones but with a jig) about once a week, maybe every other week. I don't know if there is a set amount of sharpening or a set point on my blades that I look for, when deciding to go back. I just kinda guess. Seems to work for me.

[Andrew Pitonyak]

Derek; out of curiosity, why the need to return to the grinder after only 6 sharpening's.

Stewie, you have a knack for asking questions that did not occur to me until AFTER I read your question.... then I think "yeah, that is a good question".

As usual, of course, Derek has a good answer (mention that here rather than responding below and saving a post).

[Andrew Pitonyak]

I'm wondering how you guys resharpen your chisels and handplane blades.

I hollow grind on a Tormek. The "hollow" helps me hold the blade so that I can free hand after that. Although I do frequent touch-ups free hand, it is a rare occasion for me to bring it back to the Tormek. After I have the Tormek fired up, however, I might sharpen a few things that I could wait a bit.



I always put a microbevel on my blades and when they get dull, I only resharpen the microbevel and then remove the burr on the back.

That is when I do my "touch-up".



I'm thinking that at some point I'm gonna have to resharpen the primary bevel no ? How often should one completely resharpen the whole thing ? My understanding is that each time I redo the microbevel, it ends up getting bigger and bigger

Yes. This is why some people here choose to always do the entire blade - because working by it is more work to reshape the bevel. With my Tormek, I really do not care because it is pretty fast.