Bowl Gouge Grind

[Brian Brightwell]

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This is my second attempt at sharpening my bowl gouge. I did it on my Reeder 2x72 belt grinder with a 120 grit Klingspor belt. The tool rest was set at 40 degrees. This grind came out a lot better than the first. It seemed to cut Persimmon nicely. I am new to turning and would like comments on this grind so I can improve.

[John K Jordan]

The grind looks great to me from the pictures, better than most. The proof is in the turning!

If you did that freehand on your second try I want your autograph.

Some people like more swept back wings, not necessarily to cut with but to shear scrape. I've found negative rake scrapers ground to suit me work as well or better so I'm becoming more of a fan of shorter wings.

Some may like straighter edges on the wings but the usefulness of that might depend on how you use the gouge and won't matter at all if cutting with the tip. A slight curve does make it more useful for shear scraping on the inside of a bowl. The type of flute, U, V, etc. can make a difference.

Lots of people swear by particular grind shapes but I find almost all of them will work (as long as the bevel is smooth, continuous curve all the way around for at least the first 1/16" at the edge and the edge is very sharp) - it's probably more of what you get used to. You might use this one for a month then try some variations to see if you like them better. Probably the worst thing is changing the grind constantly in search of the elusive holy grail, never spending enough time with each one. (IMO)

JKJ

[JohnC Lucas]

I'm with John Great job on the grind. I also prefer longer wings than the standard 40/40 grind. I do use the wings to cut. ON push cuts when roughing I use the lower wing to remove a lot of wood in one pass. I also use it in a pull cut to remove a lot of wood. I use the 40/40 grind mostly in a push cut.

[Jerry Lear]

I think you would do better with straight wings.I have been using Stuart Batty's profile for some time and it is the best preforming grind I have ever used

[Brian Brightwell]

Thanks for the feedback. I really don't understand all the intricacies of this tool and the different grinds, so I think I will get familiar with one shape before trying something different. I have sharpened my roughing gouge and other tools but this bowl gouge is the trickiest. I think I got lucky and found a technique that works for me.

[John K Jordan]

Thanks for the feedback. I really don't understand all the intricacies of this tool and the different grinds, so I think I will get familiar with one shape before trying something different. I have sharpened my roughing gouge and other tools but this bowl gouge is the trickiest. I think I got lucky and found a technique that works for me.

Brian, my observation is that very few people, if any, completely understand the intricacies of the different bowl gouge grinds!

Those who swear by one grind or the other likely do so because they have used it enough to be comfortable with it and may have even adjusted at least some of their style of turning to fit the gouge. I base this on looking at pictures of gouge grinds from all over and from different times - if one was always better than the others everyone would use it but people have been turning wood for a long time successfully with a variety of grinds. I've been reading through some old books, the latest written in 1959 that has some pictures of grinds that are far different from what I and some I know use. The author was evidently using them successfully. Some grinds may be better for some things than others but as I mentioned before, all of them will cut wood (if sharp). I think you are headed well down the track of excellence!!

JKJ

[Louie Sherwin]

Hi Brian,

I believe that you are quite correct with your interest about what is and how to make the best grind on your bowl gouges. I am pretty new to turning also and have struggled with sharpening my gouges and even when sharp being able to get consistent clean cuts without catches or other defects.

I turned to the web to learn as much as I could. So I watched many, many excellent videos by Mike Mahone, Richard Raffin, Dave Schweitzer and more. All of these folks are fantastic turners and do fantastic work. However, I could never reliably use what they were showing me and I was getting quite frustrated. I was making bowls and doing some beads and coves on spindles but mostly they looked pretty rough and I never felt that I was in control. I mean sometime everything would be working really clean. And then on the next bowl I would catch and knock the blank off the chuck every 15 seconds. And I just couldn't figure out what I was doing wrong.

It wasn't until I came across Stuart Batty's "Seven Fundamentals of Woodturning" that the light began to go on. It's not that the other folks were making bad videos but I think that they assumed too much knowledge that they accumulated over years of practice. Stuart besides being a fantastic turner also has the special ability to analyze what he is doing and also be able to explain it in a way that you can replicate his technique.

If you want to get a really good overview of his methods there is a great video up on YouTube of a demo he gave to the Rocky Mountain Woodturners called How Gouges Cut (https://youtu.be/QMVGankeK0I). It's an hour and half long but really worth the time to watch.

If you then really want to delve in to nuts a bolts of his methods there are 34+ videos he has posted on Vimeo The Seven Fundamentals of Woodturning (https://vimeo.com/woodturning)that go into detailed explanations with clear demonstrations of each part. He is all about ease of work, clean cuts (no torn grain, and repeatability.

Back to the bowl gouge grind. The grind that you show very clean and smooth. However it appears to be done on a jig and as a result has the curved edge on the wings. This is not optimal for reasons that Stuart explains in the videos. Unfortunately because of the geometry of the gouges and wheels and/or belts you have to learn how to do the 40/40 freehand. But now that I can freehand grind my gouges, albeit slowly, the result in clean and effortless cuts is well worth the effort invested in learning.

Finally I can highly recommend taking a workshop from Stuart. I was lucky enough to do one here in San Diego a couple of months ago. He does them all around the country. He frequently does them in Las Vegas in association with Woodworkers Emporium (http://www.woodworkersemporium.com/). There is one upcoming in October is you want to go to Vegas. They also sell his handle system and seem to be in frequent contact so they might know of other workshops happening.

-louie

[Brian Brightwell]

Louie, I like you, have watched many videos. I have already watched that video by Stuart Batty and it was a good one. And I,like you, was-am somewhat frustrated be the videos leaving out something that I needed. Brian Havens videos helped me out a lot. His seemed more complete to me.
The grind I did was freehand using a tool rest. If I understand you correctly, you are saying the "curved edge on the wings" should not be curved but straight? What advantages would the straight wings create?

[Reed Gray]

The curved wing vs straight wing is one of the things we argue about.... I can't really tell that it makes any difference, but that may be because of my style where I hold my tools more level, and cut more with the nose of the gouge rather than with the wings. I think the wings tend to be used more for roughing or maybe just being more metal into the wood for a cut, and shear scraping.Here, the debate comes in about push/pull cut. More than anything it is about finding out what works for you...I do platform sharpening only, and my wings almost always have an arc in them. Glenn Lucas is another very interesting turner to watch, as is Jimmy Clewes... Well, I have a bunch of videos up too...

robo hippy

[Louie Sherwin]

Hi Brian,

There are two possible problems that can happen if your wings are curved and you are using Stuart's style of push cut. Keep in mind that the goal of each cut is to have the nose slicing the end grain and the wings peal the side grain waste.

First it will be pealing the side grain at the top of the curve but tearing end grain more and more at the edges of the wing. Is just as though you tried to start using a spindle roughing gouge in the center a spindle blank instead of making tapering cuts towards the end. When do that you immediately create a wall of end grain on each side of the cut and the gouge stalls.

Second if the curve of the wing is ahead of the nose it will be pealing side grain before the nose slices. This will cause the end grain to tear before it is cleanly sliced making a poor finish. This is also the reason that you want the wings to be swept back to 40 degrees. That allows the nose to slice before the wings peal the waste.

Looking again at the pictures of your gouge it looks to me that the curve of the wings are out in front of the tip. I suspect that you are not very clean cuts with that grind. With a correctly sharpened and shaped 40/40 bowl gouge you should be able to get completely clean cuts with no torn grain on outside and the first two thirds of the inside of any bowl or across the end of any spindle.

Here is a YouTube video Cindy Drozda - Sharpening Gouges for Woodturning (https://youtu.be/4_KDSIDAtGc) demonstrating how to sharpen a 40/40 gouge (about a 1:30).

-louie

[Brian Brightwell]

Reed, I have watched many, but not all of your videos, and have learned from each of them. Thank You for doing them.
Louie, on the Persimmon I tried this gouge on the push cuts I tried were very smooth. I was very happy with them.

[Brian Deakin]

Stuart Batty 40/40 grind



Please see links below they may be helpful

https://www.youtube.com/watch?v=0fv0ixnEOzE

http://www.dmwoodturners.com/wp-content/uploads/2016/11/Batty_40-40_Gouge_sharpening_illustrated.pdf

http://www.dmwoodturners.com/wp-content/uploads/2016/11/Stuart-Batty-40-40-Grind-Photos.pdf

https://www.petermiao.com/news/2017/11/11/a-jig-for-4040-grind

http://www.woodcentral.com/woodworking/forum/archives_turning.pl/bid/2001/md/read/id/496555/sbj/stewart-batty-40-40-grind-with-wolverine-jig/


And

https://www.youtube.com/watch?v=Jcb2z_7YoJc&start_radio=1&list=RDJcb2z_7YoJc


I would like to know if the app below would be another possible method of setting the angle of a grinder platform but I am unsure of the math surronding tangents and circles
Can other members please comment


The iPhone app store

angle meter nakhan phageechat


regards Brian

[Grant Wilkinson]

I'm a relative newbie to turning and sharpening, but I find it interesting and somewhat confusing when turners say that the wings should be straight.

Doug Thompson tools come ready to use, and Doug advocates for the convex curve edge on the wings, very similar to yours. The pictures that I've seen of Jimmy Clewes' gouges seem to have a convex curved wing and he advocates using a jig to sharpen. I think the best advice you have received here is to use what works for you, since if you ask 10 experts how to sharpen and to what angles, you will get at least 12 methods. :-)

[Brian Brightwell]

Louie, I reread your post and I think I understand what you are telling me.

Thanks Brian, I will check out the links.

[Reed Gray]

Louie, I have been pondering this for several days, and reading it a number of times, and I don't get your comment here...I did take a work shop with Stuart and Allen Batty some years ago, and have a fairly good understanding of the 40/40 grind and cut. Stuart and I do have considerably different styles in part because I learned to turn on a short bed lathe (PM3520A with headstock all the way down) and he learned to turn on a long bed lathe. I do prefer a 45/45...

[QUOTE=Louie Sherwin;2823113]Hi Brian,

"There are two possible problems that can happen if your wings are curved and you are using Stuart's style of push cut. Keep in mind that the goal of each cut is to have the nose slicing the end grain and the wings peal the side grain waste."
For this part, no matter how you present the tool, and what style you use to cut, nose or wing. the whole cutting edge runs into end grain twice, and side grain twice: going down hill/with the grain, and going up hill/against the grain. I can't see how one part would only cut end grain, and the other only cut side grain. I do cut with the flutes rolled over at almost 90 degrees, and using this method, the nose is doing a shear cut, and the wing is doing more of a scraping cut. The scraping part of the cut would tear out more, but the nose slices away the tear out, as long as your tool is sharp, and you are not pushing too hard. Perhaps this is what your next comment is referring to. If You are using a dropped handle push or pull cut, the wing is doing more of a shear scrape rather than a scraping cut like a scraper does. This is very commonly used, and can cut very cleanly.

"First it will be pealing the side grain at the top of the curve but tearing end grain more and more at the edges of the wing. Is just as though you tried to start using a spindle roughing gouge in the center a spindle blank instead of making tapering cuts towards the end. When do that you immediately create a wall of end grain on each side of the cut and the gouge stalls."


"Second if the curve of the wing is ahead of the nose it will be pealing side grain before the nose slices. This will cause the end grain to tear before it is cleanly sliced making a poor finish. This is also the reason that you want the wings to be swept back to 40 degrees. That allows the nose to slice before the wings peal the waste."

Well, unless the grind is really bad and the curve is ahead of the nose to begin with, I can't see this happening... The pull cut, which Mike Mahoney uses is generally done with the handle low, and the wings ahead of the nose, with the handle angled toward the rim of the bowl. This is a bevel rubbing high angle shear cut, and the nose pretty much never enters the cut. A slight arc in the wing is a common profile for the 'Irish' grind and the Ellsworth grind tends to be more straight. These can make very clean cuts.

"Looking again at the pictures of your gouge it looks to me that the curve of the wings are out in front of the tip. I suspect that you are not very clean cuts with that grind. With a correctly sharpened and shaped 40/40 bowl gouge you should be able to get completely clean cuts with no torn grain on outside and the first two thirds of the inside of any bowl or across the end of any spindle."

The grind on Brian's gouges is almost identical to my grinds. The 40/40 grind just doesn't feel right to me, but I do like a 45/45, and I can get very clean cuts with it... I don't know if you could post a video or not. Other than that, a play date might help me understand your points...

robo hippy

[Louie Sherwin]

Hi Reed,

Thanks for your thoughtful reply.


The grind on Brian's gouges is almost identical to my grinds. The 40/40 grind just doesn't feel right to me, but I do like a 45/45, and I can get very clean cuts with it... I don't know if you could post a video or not. Other than that, a play date might help me understand your points...


I have been thinking about a video but I would have to revert one of my gouges to attempt something like that. A play date would be fun too so if I'm ever up your way or if your ever down in SoCal give me a PM and see if we can connect.

All the discussion about grind ultimately comes down to this, "What do we find as an acceptable result of our efforts?". My standard of what is acceptable was raised way up since coming across Stuart's teaching. And that standard is now cuts with essentially no torn grain on the surfaces of a bowl or across the end grain of a spindle with a minimum of effort. I can now accomplish that more often than not.

That said I think it is useful to keep in mind that what we are doing as turners is quite a complicated skill that happens at quite high speed. At safe turning speeds something like a mile of wood is passing by the gouge every ninety seconds. There are a number of things that have to come together at the same time to turn a beautiful piece. The sharpening of tools including shape is only one element of what Stuart calls his seven fundamentals. In the end all of these have to come together at the same time to make even a single cut around the side of a bowl. This challenge is why I find craft so compelling.

-louie

[Randy Heinemann]

Brian, my observation is that very few people, if any, completely understand the intricacies of the different bowl gouge grinds!

Those who swear by one grind or the other likely do so because they have used it enough to be comfortable with it and may have even adjusted at least some of their style of turning to fit the gouge. I base this on looking at pictures of gouge grinds from all over and from different times - if one was always better than the others everyone would use it but people have been turning wood for a long time successfully with a variety of grinds. I've been reading through some old books, the latest written in 1959 that has some pictures of grinds that are far different from what I and some I know use. The author was evidently using them successfully. Some grinds may be better for some things than others but as I mentioned before, all of them will cut wood (if sharp). I think you are headed well down the track of excellence!!

JKJ

I agree with this completely. I am relatively new to turning (about a 1 1/2 years) and recently acquired 1/2", 3/8", and 1/4" "David Ellsworth" (Crowne)
gouges. They are ground at 60 degrees with swept back ends. I love them. The instructor I did a couple of sessions with likes the 40 degree grind on gouges because, when taking out the center of a bowl you don't have to bring your arm as far away from your body to start the cut (don't know if I made sense with that comment).

However, because I now use the Ellsworth ground gouges all the time and am acquiring more skill with them, I find that they work very well. In this case, the gouges are made with particle metallurgy and the steel is harder than a standard gouge. They hold an edge for a very long time, are very sharp after I sharpen them, and have been produced much improved bowl surfaces for me. I doubt that is because the 60 degree grind is superior, but more likely because I have been using them exclusively and have just gotten better with them.

So, my point is that I think the best grind and/or gouge is the one that works for you. I personally don't know anything about why one grind should work better than another or what the pros and cons of each are but, since the 60 degree grind is producing the results i want, then that works for me. I would guess that I'll get better with those gouges because I use them all the time. It's our skill with the tool that really produces the results that satisfy us.

[Reed Gray]

Louie, well, maybe you can come up to the Oregon Woodturning Symposium this coming March... I don't get down that way much at all, just too crowded for me...

Randy, funny thing about the swept back gouges/Ellsworth/Irish grind gouges, I don't use them at all any more. I did wear two of Dave's gouges down to nubs, but switched to other tools that are more specialized and work better for me... I am different...

robo hippy