Bowl Gouge - 40/40 grind

[petebucy4638]

I use the Carter and Son sharpening chart for my turning tools. For gouges, the Wolverine jig is set at 23 degrees and a 2" projection, with the angle varying depending on how you want to configure the tool. I have set up my bowl gouges at 50 degrees. My spindle gouges range from 45 degrees to 35 degrees for detail gouges. Recently, I ground a 1/2" gouge to a 40/40 grind using Ron Brown's jig. After using the 40/40 grind gouge on a couple of projects, I ground another 1/2" bowl gouge to a 40-degree angle using the Carter and Son grinding chart. The profile of the grind was a bit different, but the gouges both worked reasonably well. I don't think that I could have differentiated between the tools if I didn't know which one I was using from the color of the handle.

After comparing the 40/40 grind to the 50-degree grind, I came away with the conclusion that the 50-degree grind is better for working inside a bowl. It is better for shear scraping too. The 40/40 worked fine inside a bowl, as until transitioning at the bottom of the bowl where it was more difficult to keep riding the bevel than it was for the 50-degree grind. Granted, I could have cut most of the inside of the bowl with the 40/40 and cleaned up the side/bottom transition and bottom with a bottom-feeder gouge, which I often end up doing.

Honestly, I could not find the magic in the 40/40 grind. It is not that it does not do the job. Other than being a little grabby on some cuts, it cuts well. I just don't see the advantage of the 40/40 grind over my 50 degree grind. I suspect that I am missing something.

 

[Mike Davis]

I have been using the 40/40 for a few years and like it much better than whatever my 3/4 bowl gouge came with. I never measured it. I may get Ron's 50° setup tool and try it. For me Ron's setup tool with the Wolverine jig makes sharpening very quick and easy. So much that I used it on all my bowl gouges and never looked back, or sideways, or up, or anywhere but the bowls. I was never able to make cuts this clean before I got the 40/40 setup tool. 50 may work just as well and make the bottom transition easier. Thanks for the discussion.

 

[wndopdlr]

I am using a 50* Ellsworth, Irish, finger nail whatever grind and have not used much of anything else. On deep, small diameter bowls I sometimes have to grind the heal of the gouge to turn the inside corner, but that is rare. Someday I need to try other grinds, but it ain't broke yet. I, too, thank you for the discussion.

 

[petebucy4638]

I don't think that there is anything magical about a 50-degree grind. Carter and Son ships their bowl gouge at 50-degrees and that I what I have used since I started turning. How any grind turns out depends on the progile of the gouge. Wheter it is U-shaped, or eliptical, etc., has a big impact on how the tool will cut. My 1/2" Hurricane Tools bowl gouge with a 40-degree grind is not well suited to spindle work, whereas my 1/2" Carter and Son with a 50-degree grind is great for roughing out thick spindle stock and riding the bevel for finish cuts.

The 40-degree grind 1/2" Hurricane gouge does a lot better on bowls than it does on spindles. I sharpened that gouge using Ron Brown's 40-degree jig and resharpened it at 40-degrees using the Carter and Son settings using a Oneway sharpening jig and there was little to no difference in the finished product.

Kent from the "Turn-A-Bowl" Youtube channel makes a good case for his 55 degree, swept-back bowl gouge grind. He makes a good case for the 55-degree angle in one of his videos. However, I don't need a bowl gouge swept back that much to make good shear cuts.

My Carter and Son 3/4" "Bottom Feeder" bowl gouge has a 60-degree grind. It also a profile that does not lend itself to a swept-back grind, which is something that you don't want on a bottom feeder gouge.

I kept the 40-degree grind on a 1/2" gouge. I am going to swap in and out of the gouge rotation to see if I can find a use for it. It is such a popular grind, I am assuming that I have just not figured it out yet.

 

[petebucy4638]

I am using a 50* Ellsworth, Irish, finger nail whatever grind and have not used much of anything else. On deep, small diameter bowls I sometimes have to grind the heal of the gouge to turn the inside corner, but that is rare. Someday I need to try other grinds, but it ain't broke yet. I, too, thank you for the discussion.

The Carter and Son sharpening chart has setting for Mahoney 40-degree grinds. I have seen jigs advertised online that are supposed to make the 50-degree Ellsworth grind fairly simple. I probably should buy one and test it out.

 

[Mike Davis]

Where do you get this Carter sharpening chart? Sounds like something I would use.

 

[petebucy4638]

This is an interesting video that compares some of the common bowl gouge grinding angles.

 

[tbrad]

Where do you get this Carter sharpening chart? Sounds like something I would use.

You can order the free chart here Free! Sharpening Guide

 

[teesquare]

A true "Ellsworth grind" is 55 degrees. And I have seen some folks grind this style closer to 60 degrees. The reason for this grind - especially if you grind away the the chin or "heel" - is to allow you to us one tool for the entire interior of the bowl - rather than a gouge of choice + a bottom-of-bowl gouge. However :
If you practice the 40/40 grind and become proficient with it- in push cut fashion- it will be the BEST finish you will achieve with a gouge on the exterior of a bowl. And then if you pick up an Ellsworth 55-60 degree grind - with heel removed, you can finish the entire interior.

The 15-20 degree differential in these two gouges truly requires a little practice to get comfortable with them. The draw of the Ellsworth is valid as it makes for a great shear scraper as well. The 40/40 is the most efficient at the push cut and was developed by a 3rd generation production turner - Stuart Batty

As it happens - David Ellsworth is a friend and neighbor as well as fellow club member of mine. Stuart is also a friend and I have turned with him a good amount in his studio CO as well. I consider them both mentors - and at the pinnacle of the turning craft/art. But I cannot use just one- or the other gouge and have as much control or fun.
Hope this helps and feel free to reach out to me if I can be of any assistance.
T

 

[JRedding]

I just took David’s 3 day class at his home a few weeks ago (he and his wife Wendy are the nicest people in the world) and he taught sharpening his bowl gouges to 60 degrees. It’s been a complete eye opener - I now use that one gouge for everything except cleaning the bottoms of the interior, where he taught using a 75 - 80 degree bottom bowl gouge. I have so far to go in my turning, but if you love to turn and get the chance, take David’s class in the Asheville area!

 

[petebucy4638]

A true "Ellsworth grind" is 55 degrees. And I have seen some folks grind this style closer to 60 degrees. The reason for this grind - especially if you grind away the the chin or "heel" - is to allow you to us one tool for the entire interior of the bowl - rather than a gouge of choice + a bottom-of-bowl gouge. However :
If you practice the 40/40 grind and become proficient with it- in push cut fashion- it will be the BEST finish you will achieve with a gouge on the exterior of a bowl. And then if you pick up an Ellsworth 55-60 degree grind - with heel removed, you can finish the entire interior.

The 15-20 degree differential in these two gouges truly requires a little practice to get comfortable with them. The draw of the Ellsworth is valid as it makes for a great shear scraper as well. The 40/40 is the most efficient at the push cut and was developed by a 3rd generation production turner - Stuart Batty

As it happens - David Ellsworth is a friend and neighbor as well as fellow club member of mine. Stuart is also a friend and I have turned with him a good amount in his studio CO as well. I consider them both mentors - and at the pinnacle of the turning craft/art. But I cannot use just one- or the other gouge and have as much control or fun.
Hope this helps and feel free to reach out to me if I can be of any assistance.
T

My takeaway from using a 40-degree fingernail grind and a 50-degree swept back grind is that it each tool has its own niche. The 40-degree grind for push cuts on the exterior of a bowl and the 50-degree grind, with the heel ground, for the interior. In many cases, I end up using the 60-degree bottom-feeder too. However, I get excellent push cuts on the exterior of a bowl with a 50-degree bowl gouge where the heel is left intact. I am going to grind one of my 1/2" bowl gouges to a 60 degree, swept back profile, with its primary function to be shear scraping. With the heel ground back, it will be interesting to see how this grind does on the inside of a bowl, compared to my current 50-degree grind.

 

[teesquare]

Give it a try Pete. I find that there are MANY "successful" grinds. And typically - the degree of success for each turner comes from how much the turner has an open mind about trying something new - AND....allowing enough time/practice to develop the muscle memory associated with each grind. I would not try more than one new grind at a time. A "time" meaning - only after developing new muscle memory for that one - before trying another. This is a highly variable time frame and very individual....but I do think that once you have the "feel" for an Ellsworth, then say - a 40/40....or your 50 degree as an example - the differences in additional gouges become easier to discern as you try them.
Be observant of proper feet positioning before you start the cut. Practice following the cut all of the way thru to completion before actually touching the wood ( lathe off ). If you find that you must re-position your feet - then correct your foot position.
My first mentor was Joe Ruminski. Joe taught me to "start uncomfortable - and finish comfortably" - speaking of the cut.

I teach turning, and find it useful to really start at the beginning of the cut - which is your foot positioning before you start a cut, so that your hips can rotate thru the cut. If I can assist further - just reach out.
T

 

[petebucy4638]

Give it a try Pete. I find that there are MANY "successful" grinds. And typically - the degree of success for each turner comes from how much the turner has an open mind about trying something new - AND....allowing enough time/practice to develop the muscle memory associated with each grind. I would not try more than one new grind at a time. A "time" meaning - only after developing new muscle memory for that one - before trying another. This is a highly variable time frame and very individual....but I do think that once you have the "feel" for an Ellsworth, then say - a 40/40....or your 50 degree as an example - the differences in additional gouges become easier to discern as you try them.
Be observant of proper feet positioning before you start the cut. Practice following the cut all of the way thru to completion before actually touching the wood ( lathe off ). If you find that you must re-position your feet - then correct your foot position.
My first mentor was Joe Ruminski. Joe taught me to "start uncomfortable - and finish comfortably" - speaking of the cut.

I teach turning, and find it useful to really start at the beginning of the cut - which is your foot positioning before you start a cut, so that your hips can rotate thru the cut. If I can assist further - just reach out.
T

I have often heard professional turners like Allan Batty or Richard Raffan comment on the value of using the tool that is in your hand at the time, instead of constantly changing tools. It makes sense that a production turner would try to make refine his tool selection so that there is minimal time lost switching tools, not to mention the level of skill that can be achieved when you have mastered a specific tool, such as a 40/40 grind bowl gouge.

Recently, I become very aware of the differences between "V" or elliptical and U-shaped bowl gouge profiles. Even with the same primary grind angle, they have different characteristics that affect how they cut. The "V" or elliptical profile cuts more like a heavy-duty spindle gouge, whereas the U-shaped profile is can handle heavy cuts better. At least in my opinion.

Woodturning has been more of an adventure than I had first expected. YouTube's videos helped a lot. Of course, this forum was invaluable.

 

[teesquare]

I would use caution when watching Youtube. Because it is a largely un-governed platform, there is no one with any experience in turning that can approve or qualify videos on turning. Have seen a LOT of bad advice and bad examples on there. But there are also a lot of good ones by known professionals that demonstrate good as well as safe practices and explain their techniques well.
As for the “U” flutes…. Careful. If you are using them for bottom of bowl gouges with a good grind or with a Continental grind and in similar fashion as a skew- fine. But it is nearly impossible to put a good side wing grind on them via a jig. So, they can be rather “grabby” when used in an orientaion that a V or eliptical flute can perform effortlessly.

I have often heard professional turners like Allan Batty or Richard Raffan comment on the value of using the tool that is in your hand at the time, instead of constantly changing tools. It makes sense that a production turner would try to make refine his tool selection so that there is minimal time lost switching tools, not to mention the level of skill that can be achieved when you have mastered a specific tool, such as a 40/40 grind bowl gouge.

Recently, I become very aware of the differences between "V" or elliptical and U-shaped bowl gouge profiles. Even with the same primary grind angle, they have different characteristics that affect how they cut. The "V" or elliptical profile cuts more like a heavy-duty spindle gouge, whereas the U-shaped profile is can handle heavy cuts better. At least in my opinion.

Woodturning has been more of an adventure than I had first expected. YouTube's videos helped a lot. Of course, this forum was invaluable.

 

[Ed Fasano]

I just took David’s 3 day class at his home a few weeks ago (he and his wife Wendy are the nicest people in the world) and he taught sharpening his bowl gouges to 60 degrees. It’s been a complete eye opener - I now use that one gouge for everything except cleaning the bottoms of the interior, where he taught using a 75 - 80 degree bottom bowl gouge. I have so far to go in my turning, but if you love to turn and get the chance, take David’s class in the Asheville area!

I too took David's 3-day class (in January 2023) and could not agree more with this post. I have had an Ellsworth 55-degree bowl gouge in my hand far more than any other tool ever since.

 

[petebucy4638]

I would use caution when watching Youtube. Because it is a largely un-governed platform, there is no one with any experience in turning that can approve or qualify videos on turning. Have seen a LOT of bad advice and bad examples on there. But there are also a lot of good ones by known professionals that demonstrate good as well as safe practices and explain their techniques well.
As for the “U” flutes…. Careful. If you are using them for bottom of bowl gouges with a good grind or with a Continental grind and in similar fashion as a skew- fine. But it is nearly impossible to put a good side wing grind on them via a jig. So, they can be rather “grabby” when used in an orientaion that a V or eliptical flute can perform effortlessly.

I tend to follow the established turners - Richard Raffan, Kent from Turn a Wood Bowl, Alan and Stewart Batty, etc. For the most part, most of the woodworkers and turners that I have seen on YouTube are relatively safety conscious, with probably the most common issues being turning bowls at very high speeds. However, I did see one turner who appeared to have a lot of experience shear-scraping the inside wall of a lidded box base with the scraper end noticeably higher than the tool rest. He commented on how that worked. He was the first turner that I have ever seen who did something like that, and it worked without a catch.

It has been my experience that U-shaped bowl gouges are 'grabbier' than "V" or elliptical gouges, especially when working inside a bowl. I think that this is because the U-shaped gouges cut more aggressively than narrower elliptical profiles. My Carter and Son 5/8", U-shaped "bottom feeder" bowl gouge took some practice to get the hang of it. It is shipped with a 60-degree angle and could probably be effectively ground to 70-degrees. You are right on target about the wings catching if you aren't careful in how it is presented to the timber.

 

[woodlaker2]

Thanks. Helpful info.