bowl gouge angle differences

[Ken Glass]

Hey Turners,

I purchased two bowl gouges form PSI (Benjamin's Best). One is a 3/8" and the other one is a 5/8" bowl gouge. I went to sharpen them after some use and found that the 3/8" gouge was ground at a much higher angle than the 5/8: gouge. Is this standard practice for theses gouges or was a grinding mistake made? If a mistake was made, and they were both to be the same angle, what should the angle be, when I regrind them? I know there is a lot of controversy on what angle to put on what, but as a rule what should they be. Anyone with a chart on all the lathe tools angle's would be great. After searching on the net, the opinions are extremely varied. It would seem to me that the less the angle the more prone to chipping you would have, but I don't know the answer as a new turner. I do know I want my tools as sharp as I can get them. I have made a jig for sharpening them all on my Worksharp WS300, and want to lock in and mark the grinding angles for each tool on my jig. So help me out guys, and no arguing about the right or wrong angle LOL........

[Barry Elder]

Ken,

You are absolutely correct about no arguing about the right or wrong angle for your gouges. That's because everyone has a different idea of what works for THEM. YOU must determine the angle that is most comfortable for YOU. There is usually an acceptable range of angles for the different types of gouges. Don't be afraid to experiment to see what angles suit your style of turning. That is another reason to contact the nearest turning club for your area and see if someone won't be willing to mentor you on the finer points of woodturning.

[Ben Gastfriend]

I have a 3/8 Bens best bowl gouge, and it came sharpened very acute and stout. It would catch on almost every cut I made. So I ground the wings back and it works great. You just have to experiment!

[Ken Glass]

Ben,
The angle on my 3/8" Ben's is close to 65 degrees and the 5/8" is/was close to 30 degrees. The 5/8" would chip when I was aggressive with it, so it is now ground close to 45 degrees. It seems to cut virtually the same, but with no chipping.

[Brian Poor]

I like an Irish or Ellsworth type grind on all my bowl gouges.
Somehow, I manage to grind freehand, but probably some type of jig will be easier - at least for that type of grind.
The swept back sides of that grind will allow the gouge to do all sorts of things a blunt grind can't.

As for angles, I'm not sure that I got the same one twice in a row in over 25 years... ;)

[Ken Glass]

Brian,
So that pretty much says, "Its the Indian and not the Arrow." Same as in golf. I will try some different angles and see after a time, which one fits me best. I guess there is a basic standard, from which everyone varies to suit themselves and their style.

[Brian Poor]

That's correct. You will find as you go, that grinds are pretty much a personal preference.
The main thing to remember is that using a lathe gouge is not very different than using a hand plane or carving gouge. The shavings are just longer.

[Gordon Seto]

Ken,
There is no perfect angle for bowl gouges. There are always trade offs.
The sharper the included angle (say 40°), the less effort for the edge to cut the wood fiber. The tool edge is less durable. It is also easy to lose the bevel on internal of deeper bowls.
If you are turning a deeper bowl, you will need the blunter included angle to reach the bottom, like 60~65° nose angle.

Stuart Batty is the proponent of the 40° grind; David Ellsworth is the 60~65° grind. Both are masters in this area. Both grinds work for their respective styles of turning. You would be better off with the Stuart Batty grind with push cuts; Ellsworth grind with the Ellsworth cuts.

You can find some useful information from this article by Dale Nish:
http://www.woodturningdesign.com/askdale/14/14.shtml

The majority of turning tools, they don't come pre-sharpened from the factory. The factory grind is only look good to sell their products.
If you don't have something to go by. This may be a starting point for you to experiment.
Sharpening.pdf (application/pdf Object) (http://www.thompsonlathetools.com/images/extra/Sharpening.pdf)

[Scott Hubl]

Looking on PSI's website at the 2 gouges, there isn't alot of info given, but from the pics it looks like the 3/8ths gouge is more of a finger nail grind, and the 5/8ths is more of a traditional grind, good for getting into that bottom curve of a bowls inside and transititioning to the bottom.

Their 1/2" seems to be ground the same way.

Plenty of info can be found doing a simple Google search on grinds and there uses.

For now, leave the grinds as they are and use them taking note as to what each can do, or not do for you, then start experimenting with other grinds. As you learn to use them and the differences you'll know more of what you want.

I guess at only 15-20 bucks each you can regrind, but i'd hate to do alot of experimental grinding on a Sorby, or other quality brand tool, and not be sure of the grind I wanted.

[Dave Rudy]

Ken,

Stuart Batty is the proponent of the 40° grind; David Ellsworth is the 60~65° grind. Both are masters in this area. Both grinds work for their respective styles of turning. You would be better off with the Stuart Batty grind with push cuts; Ellsworth grind with the Ellsworth cuts.


Just finished my 7th day of instruction with Stu Batty (phenomenal, by the way -- anyone who gets the chance to work with Stu should take it!). The 40 degree angle does not just work for push cuts -- but when doing bowls, of course the inside cuts are predominantly push cuts.

There seems to be some confusion about Ellsworth grind vs Ellsworth gouge. Hopefully I'm not about to make it worse. My understanding is that the Ellsworth grind is essentially a synonym for fingernail grind or Irish grind or swept back grind. The Ellsworth gouge is a particular tool designed by David Ellsworth which has approximately a u-shaped flute with a relatively blunt tip.

I use the Glaser-style gouge, which is a V-shaped flute which presents a relatively sharp tip. (I have several, including the AAW commemorative gouges and Doug Thompson gouges (he uses the Glaser shape)

All of mine are fingernail grinds with 40 degree bevels. They cut beautifully, and hold an edge for a long time. (Especially the ones made from 10V steel).

When cleaning up the bowl bottom, I switch to a traditional grind Sorby 1/2" gouge which has a micro-bevel ground at whatever angle is necessary to get the gouge past the bowl edge (somewhere between 60 and 75 degrees usually). It makes a great cleanup pass at the bottom.

Stu has a good point. For any wood other than softwood, there is no reason to grind gouges at any angle other than 40 degrees. If you standardize, it helps you learn to feel the right grinding angle (and you rarely have to change the platform angle on the grinder). If you have different angles on every tool, it can get awfully time-consuming and confusing. And if you get negligible improvement from different angles, why bother?

[Gordon Seto]

7 day class with Stuart, that's a big gloat. I took his two day class years ago. There is so much to learn from him; I would like to take a refresher course. In our class, he let us use his 3/4" big and long Glaser traditional grind gouge to finish the bowl bottom.
If you have a chance to compare the original Jerry Glaser gouge to the Thompson V gouge, you will find the Thompson V has slightly opened the flute.
Our NCWT Club had Bill Grumbine for two day demo. He did a bowl gouge clinic yesterday. Some members brought their bowl gouges for tweaking. We had them side by side, they are not the same V shape.
Doug Thompson is member of our Club. He mills his gouges himself. He is a cowboy hat turner. I saw some of his prototype gouges with different flute radius and depth. He said by experimenting, he has found the combination for flute depth and side wall angle that he believes it has the most efficiency and without clogging. I know the similarity between Thompson and original Glaser is just the A-11 steel, the flute may be similar but different.

BTW, if you are comparing the new Glaser tool by the new owner, I know nothing about them. They are too rich for me.

[Dave Rudy]

Thanks, Gordon. Actually 3 classes over a number of months. I feel really fortunate to be able to participate. Stu is not only one of the top spindle and bowl turners in the world today, he is also an exceptional teacher. Knowing the craft and communicating it, being patient and helping students to really grasp it are very different skills.

Thanks for the info on the Glaser vs Thompson flutes. I was under the impression that the Thompson flutes were the same as Jerry's original design, and appreciate learning better.

I have used that incredible Glaser traditional grind gouge and it is something else! Also some of Stu's monster negative rake scrapers.

BTW, Stu encourages any student who has already been through his two day class to come back and do another any time -- only as an advanced student, you can do advanced projects instead of what the first-time takers are doing -- I just did two solid days of natural edge and calabash bowls. You should give me a call or email -- PM me if you want the info.

Dave

[Gordon Seto]

Dave,

I envy your classes with Stuart. His techniques are difficult to master. It makes perfect sense to take time to practice what was learned, then take another class at a later date.

Gordon