Best grind for transition area of a bowl

[Dueane Hicks]

What grind on a 5/8 bowl gouge is best for the transition area of a bowl (that small area from the side to the bottom)? I have problems with the gouge catching, or even cutting in this area.

[Kyle Iwamoto]

Google Bottom of the Bowl gouge and Stuart Batty. He has good info. Do you have an "extra" gouge? Unfortunately, if you grind the gouge that way, it's pretty useless in other operations. I have a couple ground this way.
On almost all of my other gouges I have a 65 degree Ellsworth type grind. If you drop the end of handle as you make that turn, it may work for you. It's a bit scary at first, but after the scariness is over, it works. There is a lot of tool hanging off the rest. It may work only because the wing is swept so far back.

[Prashun Patel]

I humbly suggest that it is not the grind that matters too much - maybe at the margins, but not for the vast majority of us.

I suggest two things:

Focusing on the roll of the flute.
Focusing on designing bowls where the side walls transition gradually to the bottom; maybe even ditching the thinking that there is a side wall and a bottom altogether.

The grind may help with the finish of the cut, but minimizing catches is technique imho.

[roger wiegand]

I'm with Prashun on this one. Pick any one of the standard grinds and then make a hundred or two bowls, focusing on getting a good clean cut through that transition, each time as you make the cut while roughing the bowl. If you approach every cut as though it's going to be your finish cut you'll get a lot more practice in. Maybe, after that, you'll have sufficient distinctions to know whether the grind makes a difference. (I haven't reached that point yet)

I do have a gouge that I ground with a "bottom feeder" type grind, but I'm increasingly finding that I forget to grab it and do everything with the same Irish/Ellsworth/whatever swept back tool. That said, I've also done whole bowls with the blunt grind because that's what my teacher at that time used. It worked too, I have a preference for the swept-back tool, mainly because it allows me to shear scrape and it seems more versatile.

Perhaps after I've done a thousand bowls I'll have enough skill to understand and make use of differences in the grind. The fact that different pros who have each done 10,000's of bowls don't all use exactly the same tool strongly suggests that there is not a single "right" answer.

[Don Stephan]

With the lathe off, practice moving your bowl gouge down the inside of the side of the bowl and through the transition and onto the bottom. Can you move this path while keeping the bevel gliding on the various surfaces? (You may need a strong light and an observer.) If the answer is yes, then perhaps the bevel is not staying in contact when the lathe is running.

It has not been mentioned, but a "wide" bevel can leave what are called burnish marks that are etremely time consuming to sand out. They are caused by the heel pressing onto the wood. Because the transition typically is a concave surface, as the bevel glides along the surface it is only making contact with the wood at the cutting edge and the heel.

To avoid these burnish marks, many will grind back the heel and lower part of the bevel. It was hard for me to accept early on, but the bevel can be as narrow as 1/8" and still function well gliding along the surface, of flat, concave, and convex surfaces.

It is not mentioned in the original post, but another problem can arise with deep bowls, or "containing" bowls where the rim is a smaller diameter than the side of the bowl. As the bevel glides into and along the transition, the bar of the gouge hits the rim, lifting the cutting edge off the wood and the gouge stops cutting.

[Richard Coers]

I humbly suggest that it is not the grind that matters too much - maybe at the margins, but not for the vast majority of us.

I suggest two things:

Focusing on the roll of the flute.
Focusing on designing bowls where the side walls transition gradually to the bottom; maybe even ditching the thinking that there is a side wall and a bottom altogether.

The grind may help with the finish of the cut, but minimizing catches is technique imho.

Great point! What bowl shape are you making? Vertical sides and flat bottom, or centenary curve?

[Reed Gray]

I have a number of BOB tools, from 60 to 70 degree bevels and different flute designs from Doug Thompson's fluteless gouge to a half round flute gouge from Craft Supplies. Most of the time I go to the 70 degree bevel with a very slightly swept back grind ). If you are getting catches, then most likely, you are using too sharp of a bevel grind, and/or coming off of the bevel, and/or catching the wing.

robo hippy

[robert baccus]

I stumbled upon the BF grind decades ago (not alone I'm sure) and helped spread the word before there was a SC. I grind to 70-75 deg grind and maybe pass a diamond card on that too. You can easily do the tranistion zone And the bottom of bowls also. Good for some tough finishing cuts anywhere also. I keep a 1" spindle gouge ground to this also--great on bowl and vase exteriors--especially green p[ieces. Did I mention also enough.