Back Bevel Chisel Trick - Does it really work?
Вставка
- Опубліковано 4 тра 2022
- Back Bevel Chisel Trick. Rob Cosman tests the idea of sharpening a chisel using the David Charlesworth ruler trick that puts a back bevel on a chisel. Does it really work? Watch and find out.Back Bevel Chisel Trick.
----------
If you like our content please LIKE us, SUBSCRIBE to our UA-cam channel, and RING THE BELL to be notified whenever we release a new video.
_______
* SUBSCRIBE TO ROB"S MONTHLY WOODWORKING TIPS NEWSLETTER - lp.constantcontactpages.com/s...
*VIDEOS ROB MENTIONS:
- Stumby Nubs video: • DEBUNKED- The experts ...
- David Charlesworth Channel: / davidcharlesworth
* SUBSCRIBE TO ROB'S UA-cam CHANNEL TO TAKE YOUR WOODWORKING TO THE NEXT LEVEL: / robcosmancom
* POPULAR VIDEO PLAYLISTS:
- Sharpening Plane Blades and Chisels: • Sharpening Hand Plane ...
- Hand Plane Basics: • Hand Plane Basics
- Woodworking Tips and Tricks: • Woodworking Tips & Tricks
- Hand Cut Dovetails: • Dovetails by Hand
- Best of Rob Cosman Videos: • Best of Rob Cosman You...
- Tool Reviews: • Tool Reviews
- Rob Cosman Workbench: • Rob Cosman Workbench
* SUBSCRIBE TO ROB'S ONLINE WORKSHOP - robcosman.com/pages/rob-s-onl...
* LIVE UA-cam WORSHOPS - Every other saturday at 6:00pm Eastern Time
* QUESTIONS - Have a question about the Tools, Techniques, or Anything Else you saw in this video? Post your question in the comments section of this video!
* VISIT OUR STORE - To learn more or purchase any of the tools you saw Rob use in this video, please visit our retail store at www.robcosman.com
* LEARN ABOUT ROB'S PURPLE HEART PROJECT: robcosman.com/pages/php-what-...
* DONATE TO THE PURPLE HEART PROJECT: robcosman.com/products/how-to...
* FOLLOW US ON SOCIAL MEDIA:
FACEBOOK - / robcosman
INSTAGRAM - / robcosman_handtoolwood... - Навчання та стиль
Got sharp chisels? Let Rob teach you how to sharpen your chisels: ua-cam.com/video/FIMx5HWLHdI/v-deo.html
Also, Love everything about this debate. Two skilled craftsmen, debating the merits of an idea respectfully, doing their own experiments... I feel like I'm actually learning something here, rather than watching a flame war. Great content!
It is a pleasure to see two imminently qualified experts discuss and carefully examine alternative aspects of woodworking processes. Thanks and I appreciate the information about when each method could be best.
What I appreciate in this discussion is taking care to talk about the tradeoffs: WHY and WHEN the flat-back standard is good, and when a faster sharpening method is good enough. Being too dogmatic about only ever following the "best" practice can in some circumstances lead to a worse outcome, if you don't understand why they best practice is usually better.
My profession is software development, and just like with any field, you'll encounter lots of opinions about what the best practices are for how to write code that will be the most workable and understandable for other programmers who will have to work with or modify your code later. Most of the time they really are the best practices, but there's usually a cost in extra time and mental energy spent in order to follow that practice. That can be in tension with very real business needs to get software in the hands of users rapidly enough to not get outraced by competitors; or other factors where timeliness is more critical than having perfect polish from the start. And programmer time is expensive, and engineering and polishing EVERY part of the code to a perfect standard just isn't feasible. So it takes an instinct and experience to know which parts of the code are worth really polishing up well, and which areas, if you spent that effort, would just amount to polishing a turd.
An appreciation of when and where good enough is good enough is not merely a matter of having the emotional tolerance of accepting that some parts of your work aren't fully polished. Being too refined in inappropriate parts of a project can actually lead to an inferior overall result, to a product that doesn't make it to market in time, or to something that's well polished in aspects the customer doesn't care about, but clunky in areas they do care about.
Rob -- I watched Stumpy's video within minutes of it's being posted. I hoped that you would respond with your own perspective. You did so respectfully and I believe both channels benefit from this type of dialog. I know I learned from both videos and have learned a lot from both of you.
I think its a healthy and worthy debate. Good points on all sides
@@RobCosmanWoodworking would the whole back of the chisel have to be flattened?
Great thoughts and perspective! I watched both videos and I will back bevel my cheap chisels and prepare the back on the IBC chisels I bought from you Rob. The results you demonstrated speak for themselves. Thanks. Take care.
I think that is a good strategy
Thank you Rob for your honesty
I learned about the Charlesworth Ruler Trick from you and I've been using it ever since. So it was perfect to watch you talk about this, which I've wondered many times. It's interesting to hear you say that David added a level of precision to woodworking that was not there prior; I feel that you've introduced me to a level of precision in woodworking that I'd not known prior. Thanks for everything I've learned from your channel!
Thank you for watching and commenting
I have already seen "Stumpy"s" video. Thank you for investigating further. This kind of interaction is how a craft improves! I look forward to "experimenting" on a few chisels that I have several of a single size. As a side note, because I am currently working softwood, I have set aside three ( 1/4, 1/2, 3/4) to try your 17 degree approach. This is so much fun! Thank you for the smiles!
I think you will really like the results of the 17 degree in soft wood.
I’ve tried the 17 degrees on soft wood and it made a big difference. It went from massive tear outs to a nice smooth surface.
@@danielsimonsson2570 I also prepared a chisel at 17 degrees some years ago, when Rob posted it. It works beautifully. Thanks God, I never work with softwoods though...
Thanks Rob. I have long debated if this was an option but you confirmed all my suspicions.
Spot on!
Thank you so much Rob what a wonderful video
A great topic to discuss. I have actually done this with one of my mortising chisels.
Great explanation and demonstration and camera work. Thanks for sharing.
That was amazing! It answered several questions I have had about the use of chisels, I have no desire to build furniture but still taking my skill set to the next level is always a major goal. thanks
Rob! You're the man! Thanks for doing this video. I'm a fan of Stumpy, but I knew when he posted that video that the Charlesworth ruler technique would not work for the techniques I've learned from you. As I always say in your tool reviews, THANK YOU for your contributions to the craft and a bigger thanks for your Purple Heart Project!
Yup when we saw Stumpy's video we had to do a test and get our opinion out there
Nice comparison. Thanks for showing differences.
Always good to hear respect for David Charlesworth. As time moves on and David didn’t actively pursue UA-cam, knowledge of him is waning, along with his influence. I feel so very fortunate to have worked one-on-one with him in his workshop in Hartland, North Devon, England for a week in early 2019. What I learned from him will last a lifetime. Now that David has recently passed, there are no more direct classes. However, Lie-Nielsen still carries his definitive DVD library. Still, DVDs themselves are rapidly fading from use, so I wonder if we are moving into an era that will forget David Charlesworth. I do hope not.
Great video Rob as always. I am going to give this a go. Thanks for sharing your knowledge with us. Thanks again.
you bet
Nice comparison and application based approach.
This is a great video ❤
I agree with your findings. I like the back bevel idea for a quick way to sharpen my utility carpentry and household "fixer upper" chisels but not my fine woodworking tools.
Great minds think alike !
Unfortunately David's health is not so good. He has had to stop taking students
Great video.
Great test
Been watching him for yrs now, great channel. I love to see y'all challenging normals
Awesome thank you!
Cheers for a civilized point-counterpoint examination of the approaches to, and applications for chisel sharpening. I watched the Stumpy video and I think we are all a bit wiser now on both approaches. Thank you.
Glad you enjoyed it! That's exactly what we were trying to achieve
Fair and objective comparison.
That's what we were going for
There is so much great content available for you, stumby nubs, and many others. I love that you are willing to mention, praise and respectfully challenge other UA-camrs. It shows a genuine respect and dedication to the craft. I think the most valuble lesson here is that it is good to try new things but we have the responsibilty to verify that the new thing is better and also better for what we are doing. Situational application is so important.
Well said.
I've been waiting all week for this video.
And thus you received it !!!!
Nice demonstration and I agree with you 100 percent.
Thanks for watching!
Very much enjoyed your careful analysis of the techniques. I am kinda lazy, especially when it comes to sharpening, so I have been just ignoring the backs of my 'plain' chisels as they don't get used for precision work. I'm going to start using the ruler trick on them, thanks to you and Mr Hamilton. For precise work, I'll stick with the whole back flattening after seeing your example uses. As always I'm impressed with the quality, honesty, utility, (and viewing experience) of your video as well as Stumpy's. These are the reasons for I watch and enjoy both of you, and I hope that you will both continue with long and prosperous careers. Last but not least, thanks for your wonderful PHP, so nice to see veterans benefit (especially the ones less fortunate than me)!!
And now we know! Thanks for the test work.
Thanks for watching and commenting
UA-cam put this video in my feed straight after watching Stumpy's video. Just using similar triangles, if the rise of the back bevel is 1.5 thou (0.038mm) and it runs back 1mm from the tip then for a 270mm long chisel the back has to be lifted 10mm for the cutting edge to engage.
I watched Stumpy a few days ago and was really surprised. Great comments Rob!
I hoped it help you understand the pros and cons
good video with evidence
Thanks! Glad to see a response for Stumpy's video. He has a point, I just hope that viewers did not misinterpret it and think that it's okay to use the trick regardless of the task.
I personally find it easy to maintain the flatness of the back of the chisel to have a need for time saving method, even if it's for non precision work.
Thank you for sharing. Seems would be great in some uses. From Henrico County Virginia
I have a lot of respect for Stumpy but I was kinda surprised that he recommended this technique. You proved this way is not 100%, especially when doing dovetails. Thanks
I thoroughly enjoyed your and Stumpy's video. After seeing Stumpy's video, one of my first thoughts was to "almost" flush cut dowels. There have been times when the edge of my chisel gouged the wood around the dowel. Doesn't make for a good day. I realized Stumpy's process would leave a slight amount of wood on the dowel. I added a tiny back bevel using a couple swipes on a 9" sheet of 10,000 grit lapping film and a ruler. So, I have almost no back bevel, but the chisel still glides above the wood surface. The remaining wisp of dowel can be cleaned up with minimal sanding or scraping. I only back-beveled 2 of my cheaper chisels and don't intend to do any more. But, it was interesting. I appreciate all you do for the woodworking community.
You are genuinely humble enough to give the fullest credit to David Charlesworth. Thankful to you this is one of the puzzles in my mind whether to use the ruler trick on chisels.
glad I could give you some helpful. Unfortunately David;s health is not so good right now
Rob you are 200% correct on this evaluation for Chisels flattening and sharpening for performance and application.
All chisels are to be flat back and fully polished basks and primary, secondary as well for pair or skew chisels they should polished all the way around on all surfaces since you are using both hands to control the chisel! a light coating of Camilia oil makes it even better. Columbus Michigan
Great follow up O Knubs premise. With additional challenge of using hand tool with but a single hand. Your perspective helps boatloads. Also, as a veteran, deep gratitude for your efforts with the PHP
Thanks for your service and your comment
I had watched Stumpy's video when it had been published, and I couldn't agree with what I saw. You confirmed my thoughts today. I stay with"the old way" for chisels.
Me too
When I purchased my set of Marples paring chisels so many years ago, I rummaged through the whole stock on display in order to select for flattest backs, best bevelling, etc. When sharpening, I settled on letting pressure bear with my thumb on the tip, when backing off on the finest stone, which is the only one I use for backing off. After a few of those, the back began to polish on the tip only, with a bit down the sides, so that it resembled a japanese chisel, only without the pronounced, intentional, hollow in those. Since I went from Arkansas oil stones to using water stones, it has become a much trickier matter where and when I apply the pressure. I do as much work on the periphery of the stones as I can, letting the middle take care of itself as an oldtimer said. Recently used a cinder block to flatten those, it worked pretty well, for zero investment.
Bloody brilliant content, your chisels are insanely sharp! thank you from Australia :)
And yes they can be bloody if you are not careful!!!!!!
Thank you Rob.
The, for me, very valuable lesson I learned is the way you start your cut with chisels. Before, I did it the way stumpy does it to, lifting the end of the chisel. In this case a backbevel won't make a big difference.
But if, and this is what I learned and will try for sure, you start the cut only by pressing down the tip of the chisel a backbevel interferes with it.
Thanks again.
Thnaks for watching and commenting
It was expected. Before I learned a bit of woodworking, it was frustrating how the plane blade or chisel would not engage and cut. Flattening the blade's backs when new saves way more time than fiddling with a chisel that is not flat afterwards.
Btw, I have seen many carpenters use plane blades as wide chisels for paring or referencing. I have done that so many times too. That is why the rear ruler trick would not work for me neither.
Thank you Rob!
I accidentally used the Ruler Trick on a set of chisels before I *knew* that I wasn't supposed to.
It was also accidental that my polished edge on the back of the chisels is only like 1/32 of an inch wide. You can barely see it, unless you hold it to the light at the right angle and are wearing magnifying glasses.
After I found out that I had *messed up* that set of chisels, I bought a new set of Narex Chisels. (The other set was a cheap set, so it wasn't a loss). I spent almost 3 hours polishing the backs of the new chisels. They look just like Robs.
After I watched Stumpy's video, I went out to the shop and tried my old chisels. I did side by side comparisons with both sets, in Pine, Padauk, Walnut, Oak and Maple. I was totally shocked to find that my cheap set that had been sharpened *wrong* performed just as good as the Narex. The cheap set seemed to cut through soft wood a bit cleaner, too. That could just be my imagination, but the cheap set does have a Slightly sharper angle on the cutting edge.
I gotta be honest, with this, and the whole End Grain Wood Glue deal, I'm starting to question everything in the workshop. When I'm doing anything, and that process has been the same for hundreds of years, I'm starting to ask *why*.
I'm excited though. This is a great time to be a woodworker. I imagine that scientists back in the 1300-1600's felt like this, when everything that everyone *knew* was being debunked by using the Scientific Method.
**This will be the only time I compare myself to a scientist during the age of Enlightenment** lol
I've always suspected that the ruler trick prevents the chip breaker from performing up to its potential. Tricky to test for sure.
Great video, I've tried to describe the experience of using my optically flat chisels from Blue Spruce Toolworks to lots of people but they typically don't understand what "reference surface" really means. The first few times I pared away a protrusion less than a half thou I was completely sold on "optically flat". I even got an optical flat off eBay to inspect my older chisels I used to think were "extremely flat"!
Thanks for the great video. It was necessary whenever an idea is challenged. Stumpy is one of my favourite woodworkers. But I will continue to try to flatten the back of my chisels. I just can’t have a few chisels in my shop function differently. I want them all to be equally reliable for every task. I don’t bother with hard to prepare old chisels anymore. It’s a waste of time preparing old tools unless that’s your hobby.
Consistency and predictability, makes for more precise and enjoyable work.
Great video. Sticking with flat back but I may start doing a micro bevel on the front for a little more strength and speed of sharpening.
That's what I do. In fact I do two microbevels on the primary bevel
Here is Mr. Cosman providing real professional woodworking education. those are the tests that matter especially the last one. Let alone multiple sharpenings which adds error to the back bevel. its funny how some channels who put five minute videos think they can prove a long held theory wrong lol
I totally agree with you
Rob, I thought of you while watching Stumpy's video a few days ago, hoping you'd test this. Thanks for the excellent insight, as usual!
Just had to throw my hat into the ring on this one
Who said your not a scientist- great educational video. 👊🏼
Thanks Rob,, i already this done this trick some time back on a couple of old chisels that were pitted on the backs, it was going to be near impossible to remove the pits the conventional way
Thats a good time to use the ruler trick on a chisel
Watching Rob pare that dowel... He's got a real Bob Ross vibe going on here - Wait a minute! Bob Ross... Rob Cos... Hey! Has anyone ever seen them in the room at the same time?!?
I don’t have the sexy Bob Ross hair though!!!!!!
Trimming dowels is EXACTLY the kind of test I wish Stumpy Nubs would have done when I watched his video a couple days ago, and I think you do a great job of using it to demonstrate the kind of situation you can't have any back bevel in. I don't know if I understand why the dovetail test was very relevant though. I think it would have been more interesting to see if you noticed the difference when cutting it freehand like you would have in actual use. If you're not using the supporting block then there is barely going to be any of the back actually touching the wood. Neither the aesthetics of the surface or it's flatness (as long as it's concave and not convex) are super critical, so you can keep adjusting the angle of the chisel until it's cutting straight.
The measurements you got with your dial indicator matched what I calculated using a little bit of trigonometry.
I noticed someone had commented that on Stumpy’s video. This was a good way to definitively measure it, as it could change depending on how much you rub it over the stone.
I watched his video first and I was hoping that you'd weigh in. Once you showed that the back bevel was .0015" I knew it didn't stand a chance. Thanks for the video!
Interesting video! I watched Stumpy Nubs' one when he posted it, and I thought that it might be worth doing to save a whole lot of time and effort. It does seem to make working with the flat side down similar to working with the bevel down, i.e., requiring a bit of care and judging the feel to avoid cutting in too deeply. I think I will give it a try for some chisels which I use for bevel down work, such as removing paint or roughing out concave features. Especially on the paint scraping, which is pretty abrasive work, and dulls edges quickly; having a better edge might mean less frequent sharpening. The ones I have been using for this are in pretty rough shape, and I have been hesitant to spend much effort polishing the backs beyond a rudimentary level.
Thanks for addressing this, I enjoyed watching and learning.
Thanks for watching and comment, I think you are on the right track
I agree with you Anthony, when you think of using this trick with chisels mainly used bevel down.
thanks
you are very welcome
As you state, it really comes down to what sort of work you do and the level of precision you are demanding. For cheap chisels - a back bevel is probably the way to go for a couple reasons. But I certainly would never do it to a high-end chisel as you’re sort of defeating the purpose of a high-end precision chisel. As with many tools - it’s a good idea to have an “A” set an a “B” set and that seems to apply here as well.
Always have a "B" set of chisels for that neighbor who wants to borrow a chisel
Rob, even David Charlesworth video at the end even states - Do not use the ruler trick on Chisels, what more should be said! This is one thing Stumpy Nubs should of watch - LOLdo not use the rul
I think the tip of your measuring dial was ball end, so a little bit of that drop would be the the circumference of the ball lowering as it slid off the edge of the chisel. Great video, as always. Thanks!
Yep, that’s why we settled on .0015. Saw .003 before it dropped off.
As a matter of fact Stumpy got me on my toes waiting for this video from you. I tried to make sense of his idea as I have so much respect to him and his scientific methods, but it simply did not add up this time (not fully at least). Great video Rob
Go fishing!
I had seen stumpy's video earlier, and came across this today, of course (you just published it yesterday) and when I saw his video, I thought it wouldn't work for me. His 'trick' works if you are lifting the chisel off of your work, but as you showed, even when paring on the pine, all you had to do was press down with your thumb when using the flat chisel, but when using the back bevel trick chisel, you had to lift it, and you lose your reference surface. You wouldn't lift a plane from the surface, you're trying to just shave off the top that sticks up above the part you want to keep - the same applies to most chisel work. His trick works well enough to save time, but for most purposes for which I use a chisel, that's not an option for me either. The flat back is the only way to get that long flat reference surface, just like a plane. Cheers!
Great comment, thanks
Good video, flat is the way to go
You got that right!
Thank you! I have room in my shop for both methods. Just as you stated, for normal work, back bevel chisels. And for dovetails (fine work), the traditional method. The former will save me a lot of time, so there is that.
Professor Pye wrote of the "workmanship of risk". Making the cabinetmaker's chisel into a carver's chisel gets rid of that last, tiny, element of the "workmanship of certainty" afforded by the tool, which I would sorely miss.
I haven't had time to watch the howle vid yet but I have been using the ruller trick for years on my plane it works great and for my chisels I Wil just lift it up slightly and pul it back ones ore twice after lapping it this way after time I Wil get a nice falt chissel with out putting a tremendous amount of time into flattening it I haven't noticed a downside in doing it this way
I have seen you do this in the past. Not sure how long ago, but not yesterday.
Thanks for the video.
No mesure required :
There is the same proportion between the width of the sharpening stone (minus the ruler) and the width of the back bevel than between the thickness of the ruler and the elevation of the edge above the reference plane.
My maths vanished !
jp from France
In "stump's" video, when he shows his flat chisel I could see the light bendind, just has you explained that is a bad sign of flattening. I immediately thought that the test he did was between 2 non flat chisels. I was looking forward to see your thoughts about it. Thank you again.
Glad you found the video helpful
Great video, Rob! How about mortise chisels? In this instance back beveled mortise chisels may still do the job without spending the time flattening the entire back?
Great video Rob and I greatly appreciate the time and thought that you have given to this topic. I anticipated your conclusions as I am familiar with David’s precision methods from watching a number of his excellent DVD’s made for Lie-Nielsen Toolworks, which I can highly recommend. Clearly Tom Lie-Nielsen is also an admirer of David’s work.
Well done Rob. I watched James go through the process and though he makes a good case, I can't do that to my chisels. I agree with your assessment. Another point to consider is that for those who rely on sanding to attain a surface they like, sure, the back-beveled edge would be fine for most things other than dovetails. Over the years I've purchased some used, good quality chisels, most I flattened and polished the back, one in particular had been poorly dressed on the back when I received it. After much effort and time, it was much better, but ended up pretty much with a slight back-bevel left. I don't use it for precision pairing for the reasons you have demonstrated. Eventually I'll get it perfect as I work the back a bit more with each sharpening and I'm too stubborn to let it beat me.😉
Never let the chisel win !!!!!!
take the ruler with you when paring
Thanks for watching and commenting
Some lifting needs to occur with a flat chisel as well. You do have more of a reference surface, but I think it has more to do with what you are used to doing and the muscle memory you have created over the years. Either method will work with experience. Have some novices try it out and see what they think.
Very interesting video Rob, I love seeing conventional wisdom challenged and put to the test! Speaking of which, did you see the video from a few months ago, where someone was testing the strength of end grain to end grain glue joints in comparison to long grain to long grain glue joints, and came to the conclusion that it's a myth that end grain joints are weaker! Would love to know your thoughts on that issue!
Rob has a video on that issue, more or less confirming the myth is busted.
I wouldn’t say confirming the myth busted, but rather modified. End-grain to end-grain gluing, though stronger than we ever thought, will still never be strong enough to find use in any application. However, end-grain to long-grain definitely has application now.
@@RobCosmanWoodworking thanks for clarifying! I knew you had some caveats in that video but I couldn’t remember what. I agree there’s no good use for an end grain to end grain joint!
@@RobCosmanWoodworking Thanks for the reply. The only application I can think of where end grain joints are important, would be in a segmented wood turning project, where the segments are generally glue end to end (mitred joints) to make the rings. Those joints need to be strong enough to hold the rings together while the top and bottom surfaces are sanded flat. Usually several rings are then glued one on top of the other (long grain to long grain) and the end grain joints would be staggered, so their strength becomes much less important at that stage once the long grain joints take over.
No crushed fibres with both examples, which I was expecting using the guide block and flat backed chisel,
I found that a sure way of undercutting,
as you cannot have any infulence whatsoever (makes a lose fitting slot on a shooting board)
I don't mind a bit of tenting if it means I can keep from going under the shoulderline.
Been meaning to make a little cast iron stock, say something similar to the wee square for this kinda thing, as it holds onto graphite very well for making witness marks compared to aluminium.
Just saying tenting maybe not such a bad idea for larger work IMO,
maybe not for your speedy demonstrations , but it could certainly get one out of a pinch, or if one needs a precision hole like
for a making panel gauge for example.
Cheers
Tom
On your second test, for example, with the plug... I feel like this method is fine for people who are already going to be sanding no matter what, because they are just sandpaper people. You can remove 90 whatever percent with the back bevel just fine, and the rest is 5 swipes with 180 or 220. If you are new, and are just going to be sanding because you don't have a plane, or you have just been told that you always have to sand everything, it's fine to back bevel it. It will save you time, and lord knows how frustrating it is as a newbie to flatten and polish chisels. Plenty of people just don't even do it early on because it is intimidating.
By the time people are hand-cutting dovetails they are going to be going all out to perfect every tool setup anyways, and will have no issue doing a full flattening.
I knew that so that why we made this video!!!!!!!
If you assume the measuring point is a sphere then as you approach the edge you will be in fact below the edge of the chisel before it falls off the edge completely. At this stage unless I am incorrect in assumption this is an incorrect method for determining the drop bevel amount. One method may be to keep the chisel on its back ( on the polished section with small bevel) onto a machined flat surface or granite plate and insert a piece of flat wood veneer into the sharp tip which will split the veneer between the machined surface and the sharp chisel tip .Measure that splintered wood thickness with a micro caliper to measure thickness at the edge of the wood where it has been sliced. This would give you the effective bevel cut.
It was a sphere which is why I used my magnifiers to determine when it was in the middle of the sphere. If you remember I read it to be .002”, but then determined that it was actually closer to .0015” in further tests.
Well researched conclusion Rob.
There is an improvement to the Charlesworth ruler trick I have been recommending to fellow woodworkers for some years now.
Instead of a ruler on the stone - use a layer or two of electrical tape on the back of the plane blade a fixed distance up from the cutting edge and parallel to it of course. I use 50mm myself and measure it for consistency. Because the micro-angle is set by the tape fixed to the blade the angle is totally consistent and MUCH easier to manage while sharpening. No fiddling with rulers slipping while sharpening. you can transfer from one stone to the next absolutely confident that the angle is the same.
The electrical tape has no impact on sharpening stones, and glides beautifully.
The added benefit is that the micro-angle is even less than with the ruler trick. Much less.
And yes I have used the electrical tape trick on chisels and found that for normal use it is fine, but not for paring work. Fortunately, I have two sets of chisels.
A very interesting idea. I will try it
@@RobCosmanWoodworking Being an accountant and maths nerd I actually calculated the angles some time back. I don't recall exactly but with my 6" ruler the angle was about 8 times what I achieved with the electrical tape, which still yielded the desired result. So, a much smaller back bevel, and having it so consistent across different stones, combined with the ease of operation was a no brainer for me. Hope it works for you. And thanks as always for the seriously helpful videos.
As I was watching your informative video (thank you), I noticed on one of your shop aprons a U.S. Army 14th Infantry patch, blue/red/gold castle with the caption, "The Right Of The Line". I'm assuming, by the flags in your shop and your accent, that you are Canadian. I'd be interested in the story of your affiliation with that military unit and/or how you acquired the patch?
Thanks again for the UA-cam content you provide!
The conclusion that a flat chisel back is better is definitely correct, but I’d be astonished if rubbing the back of the bevel on a 8000 grit stone a few times takes 8 tenths off the surface. I’ve done a fair amount of metal scraping for flatness, and my carbide metal scraper takes off about 0.0002” off cast iron, far softer than hardened tool steel. It would be interesting to see the same DTI measurement taken on the other chisel, and a measurement before and after the ruler trick is performed.
👍👍👍
Hi Rob. I love your channel. How about 'splitting the difference'? Sharpen the back of the chisel (like David suggests) but use the front bevel as reference for your cut. You would save the time sharpening and gain a bit of reference surface (obviously not near as much as with the traditional technique but more then without any surface). Just saying. Keep your good work and God bless.
That would require I sharpen the whole bevel, which would need to be done every time I resharpen.
Rob, any comments on how a plane blade back bevel can impact the fit of the chip breaker against the plane blade? Is the trick to keep the back bevel short of where the chip breaker makes contact?
I think that there is a middle ground between the 2 extremes and that middle ground seems to work fine for me. One extreme is the ruler trick applied to chisels, I don't think that it should be applied even for cheap chisels as even a woodworker that usually does not do fine work sometimes has to reference with the flat part of the chisel. The other extreme is to do like you Rob did on your chisels, a perfect flat and polished surface that extends up to the handle, awesome but fatiguing and time consuming work that IMHO is over killing. My trusted middle ground is to apply pressure only on the last couple of inches while I flatten the side opposite to the bevel, so I get a flat and polished surface that extends only that couple of inches from the cutting edge, still time consuming, but way faster. When you reference the chisel pressing with your thumb you anyway apply the pressure to that portion of the blade that is flattened doing it my way, the same is true when you remove the burr on the stone after sharpening, those 2 inches give all the flat surface that is needed for fine woodworking. By the way I called it my way, but I am not alone, I know many woodworkers that prepare their chisels that way.
Flattening the last 2 inches is all that is needed. I just prefer flattening the whole back
I use a Worksharp. I sharpen the bevel on chisels and irons and then quickly remove the burr and flatten the back. I have no need to use the ruler trick. I guess it’s only appropriate for hand sharpening to save time and effort.
it will give you a better edge. If you use the 16k stone, the resulting surface on a piece of maple will be stunning.
👍👍👍👍
Adding a back bevel to the chisel will definitely speed up the initial grinding process however how many times do we get new chisels? I’ve got 5 sets that I’ve had over the years and it was only the first grind that took the time, once done it’s right for life really 😉
I agree.
I think there is some confusion created around the ruler trick when we use the word "flatten" to mean both "to make flat" and "to polish." Making the back of the blade geometrically flat to get rid of high spots, low spots, wrinkles, or so on is one thing. To polish away grinding marks from the previous machine or stone is another. In my opinion a blade must be reasonably flat (geometrically) for the ruler trick to work effectively. The ruler trick is done, according to Charlesworth's UA-cam video, on the final polishing stone and removes very little metal. It may cure small geometric defects, but not large ones.
There is also an advantage to flattening the back of the blade so that the cap iron seats firmly and with out gaps. Once it is flat, then it can be polished using the ruler trick, in my humble opinion.
I agree with all you say
Poor Stumpy! He was eviscerated in the most humiliating manner, leaving him to suffer the indignities of having his entrails ceremoniously cleaved out and dragged before a gleeful public. How will he now face his colleagues of the craft? I hope you two are still friends after this violent expose.
I think you using hyperbole…i hope so
I don't disagree with anything shown in this video. As I said when I made mine, this was an experiment and folks who are interested should first test how it works for them on a cheap chisel (which is what I demonstrated in the video) rather than back beveling their good chisels. It worked for me in my two joinery-paring tests. My conclusion (which I should have spent more time explaining in my video) is similar to Rob's concluding comments- for the way most woodworkers use their chisels, the back bevel makes little difference in performance, especially when applied to cheap hardware store or yard sale chisels that would require a great deal of lapping to fully flatten, a process that may not be necessary for the average user. But I acknowledge that I am not planning to back bevel my good joinery chisels :)
Stumpy, I thought your video was good and clear and I love that Rob respects your work and is willing to test it himself. You both came to similar conclusions. This kind of professional back and forth is good and healthy. Thank you for exploring these topics in depth.
It is all about what your precision requirements are. If you are making fine dovetails and such, you are going to get tons of value out of all the time spent on flattening those chisels. For me, who is a hobby woodworker at best, I'm using the ruler trick, because I do not need that level of precision. Great videos from both of you.
Stumpy is the man!!! I think we just gave a model how to have a professional and respectful UA-cam discussion on an interesting woodworking topic. We should do this some more! Keep up the great work Stumpy
@@pagdesigns we didn’t flatten the back, it was right from the factory grind
@@pagdesigns The small strip along the edge is flat. The ruler merely lifts the rest of the back off the stone, concentrating the lapping on the very end. If the surface along that narrow strip was still crowned or hollow it would show as a dull spot just as it would if you were lapping the entire back.
How about a vid on sharpening gouges! Tks
I don't really use gouges so while I can sharpen them its not in my wheelhouse. I only like making videos on what is my primary work, sorry
The finger can detect 13nm that is 13 millionths of a metre. A hair is typically 70nm.
Any angled treatment on the back of the chisel is going to create a secondary angle. The area on the back of the chisel that had the ruler trick applied seemed to be about 2mm wide (hard to judge). The amount of time and effort expended in polishing the back was not shown in the video. It's be interesting to see if a significant reduction of the polish line would produce an acceptable result. But again, any back beveling will produce a secondary angle.
I think we already did that, it boils down to the balance between shat you use your chisels for and how much time you are willing to put into flattening the back
It would be interesting to see you repeat this but instead of using the ruler trick, use a strop on the back of the chisel. Prepare the chisel as normal, sharpen as normal, but as a final step, strop the back with the chisel dead flat on the strop. Some say that a strop will round the working edge. I find this isn't an issue and use a strop, but you probably achieve a level of sharpness that I don't, so I wonder if stropping would keep your paring operation from working? Part of the point of this question is that pressing into a strop does some of what the ruler trick does, but if you don't go crazy with the pressure, the angles / offsets involved are greatly reduced, I suspect.
As a matter for fine woodworkers, I think that the big question is: *_Why do a back bevel? What advantage is there?_*