Turning insides of bowls

[Dan T Jones]

I am a pretty infrequent turner. When I turn the insides of bowls, and especially when I'm close to being finished, I have a catch that ruins the bowl. I've hit 65 so maybe age.

I know that this is a chicken reaction but I was hoping someone could recommend a tool that might be "fool" proof. Mostly I get the catch when trying to use a finger nail gouge (Thompson). I could just use my non-carbide rounding tool (sort of a rounded skew) and buy lots of sandpaper.

Any suggestions?

Dan

[Allan Ferguson]

It is not age. Most likely a tool presentation issue. Find someone with experience to look over your shoulder.

[Prashun Patel]

Show us your bowls. Bigger, shallower bowls can be easier to turn than small ones. That fact was not intuitive to me as I was learning.

[Steve Mawson]

Not sure where you are getting the catch. It is never a good idea to go back toward the rim as it will flex and vibrate which leads to a major catch. A bowl needs to be finished from the outside in, a section at a time. Once a section is done don't go back, kind of stair step it down. A negative rake scraper helps take out the ridges as you go. A turning club or mentor can be a big help.

[Mike Goetzke]

Dan - I consider myself a beginner too. Recently I decided to join a turning club (Bob Bergstrom is a member too) and it just happened they had a turning instructor Stuart Batty there the weekend after I joined for a demo and then the next day for hands on instruction. I suggest you visit a club. Bob has been my biggest help. Stuart uses a 40/40 deg grind that is good for most of the bowl but not deep into the bowl. Bob (and Stuart) introduced me to to a straight ground gouge for the final cuts (called a bottom feeder) on the inside and to use for the bottom of the inside. The gouge is ground somewhat like a spindle gouge. I also learned how to use a swept back NR scraper to do a final smoothing of the inside too.

Something else that has been helpful to me is good lighting. It really helps me to see where the bevel is, where I am cutting on the gouge,...

Keep practicing!


Mike

[Brice Rogers]

You have already got some good advice. So I will touch on some things not yet mentioned.

When I'm turning the inside of a bowl, I get fewer catches it my tool rest can reach inside of the bowl. If I only have, say, 1/2 inch of overhang catches don't happen very often. I've made a few curved bowl tool rests and one that looks like an upside down L. On the "L", I can stick the "tongue" of the L inside of bowl.

I find it best to be cutting slightly above the center axis. That way, if I get a minor catch that would tend to pull the tip down, that the cutting edge gets deflected rather than getting pulled further into the catch.

I too use a "bottom feeder" gouge (mine are ground at 80 degrees) and if properly supported they don't catch very often. But they can only do the bottom and part way up on the sides.

I use a round nosed scraper with a fresh burr to remove most tool marks. If the radius of the tool starts to get close to the radius of the bowl, I'll get a catch because too much tool is being presented. Turning the scraper on its side helps making it less catchy but it requires more control to keep it at a consistent angle.

[Reed Gray]

Well, tool presentation for sure, and maybe gouge choice. So, a 60 degree bevel will go through most of bowls, from down the sides, through the transition, and across the bottom. I always roll the flutes over to about 2 o'clock position. Most catches are with the wing that is on the wood side, and not towards the center. If flutes are straight up, that can be a nasty catch.

robo hippy

[Dan T Jones]

Thank you all for the help. None of you mentioned one of the carbide tipped tools with the disk shaped bits. I thought that might limit the possibility of a catch.

Definitely the catches are on the inside side of the bowl and a small bowl. I'll try to post a picture.

Dan

[Brice Rogers]

The carbide tools with the disk shaped inserts are basically just scrapers. If presented below center line, or with too much overhang, they tend to be a little catchy too. I suspect that they are less catchy when they are new and sharp and less so as they dull. If a round nose HSS scraper catches, they will too.

Negative rake scrapers (especially freshly sharpened and with a nice burr) are nice finishing tools inside of bowls, but they aren't meant for removing very much material.

[John K Jordan]

Maybe a closeup picture of your gouge and another picture showing where it is in the bowl when you get the catch. For the inside I like a bowl gouge that is not ground to as sharp an angle as I might use on the outside and with the wings not swept back as much.

I also really like the Hunter tools for insides of things in many cases.

JKJ