Scooping out a bowl

[Brad Hammond]

how do you guys scoop out a bowl? i know every technique is different for each person so this is a kinda poll question.
i'm havin the awfulest time learning this technique. i'm using a fingernail profile on my gouge, and i've been trying bill grumbine's technique, but i keep running across the face of the bowl. then when i switch to a scraper i seem to be getting catches here and there.

thanx all !

brad

[Chris LaPine]

Brad,
Most likely you will will get many techniques. I assume the problem is at the edge of the bowl when starting a new cut and the tool kicks back towards you. I used to cheat and use a skew tool to start the cut and then go back to the gouge and start riding the bevel. It works but takes too much time so I just kept watching videos and practicing. I was told that if the tool skates towards you then you have to move the tool handle further out such that only the tip starts into the cut. Once engaged then the tool can be rolled back.
Chris

[Brad Hammond]

hmmmmmm good advice! i'll try that too!

[John Hart]

Brad....my method changes with every piece it seems....And I can't use a gouge worth beans.:o You may be experiencing a "heavy touch", although, I've had the problem you describe even with a light touch, using a large profile tool. I've found that reducing the size of the tool greatly reduces the tendancy toward catches....Probably the reason that most hollowing tools are the very small bit type.

But...this is probably not what you're talking about. My other wondering is How close is your toolrest to the surface of the wood? It should hug it pretty close.

[Bill Grumbine]

Hi Brad

It can be difficult to diagnose what is happening without seeing it happen, but it may be that you have your tool rest just a little too low. It all depends on which way the gouge is running across the bowl. If it is running to the right, or towards center, it is likely that the rest is too low, and the wood is actually moving away from the tool. When you press harder to make it cut, it takes you for a ride.

If the gouge is running to the left, it is being "thrown out" by the wood, and requires a little different presentation that what you are doing. You can either swing the handle further away from you, or roll the flute over on its side so that it is in a shear scrape position, or both. Both of these techniques help to minimize the tool being thrown out as it enters the wood. Once you get it in the cut, you can roll it back up to its optimum cutting position. It only takes a tiny amount of bevel support to get it going. Getting it going is the hard part.

Scrapers are wonderful tools that can do everything from take wispy shavings to remove tearout, to taking huge chunks to remove bowls from the lathe. A light touch is required, as well as proper tool position. Dead flat on center, or with the handle raised just a hair on center is good. Anything else is asking for trouble.

I hope this helps you out some. If it doesn't, perhaps you could show us a picture or give us some more details of what is happening.

Bill

[George Tokarev]

how do you guys scoop out a bowl? i know every technique is different for each person so this is a kinda poll question.
i'm havin the awfulest time learning this technique. i'm using a fingernail profile on my gouge, and i've been trying bill grumbine's technique, but i keep running across the face of the bowl. then when i switch to a scraper i seem to be getting catches here and there.


Tool control. Then tool presentation. First gain and remain in control. Start slow so the force you have to fight is less. Mass times velocity squared, remember? Second, keep the rest up as close as you can. This gives you leverage, especially if you have your off hand over the tool, holding it firmly to the rest, with your "good" hand at the end of the tool handle. Now that you've Anchored the tool to the rest, get the Bevel close and parallel to where you will cut, and Cut in an arc, locking up your small muscles and using your body English or a shift of weight from one leg to the other. A-B-C.

You can't reference a bevel to air, so don't try. All you end up doing is following into the space, and maybe getting underneath something still sticking out. Use the fulcrum of your toolrest and sweep the tool in and out in overlapping arcs until you can get a nearly continuous surface. I'm sure you've gone down at least one washboard road in your life. Even with good shock absorbers it's tough to maintain control, and becomes tougher with greater speed. With no shock absorbers, as here, it becomes impossible. Remember this, and even when you are cleaning up a surface and begin to develop chatter, go back to the toolrest reference only, scooping in to regain a steady bevel reference.

That's a bevel reference. Not "riding" the bevel. Riding the bevel takes away whatever shock-absorbing capability you have and lets the soft spots or missing spots take over. Once you have an entry, you can establish a surface. Once you have a surface, you can refine from the poke cut you used to enter to a peel cut to remove shavings. Here's where that close rest and that good anchor pays additional dividends. You can use perceptible larger movements out at the handle to make smaller, barely perceptible adjustment to the tip of your tool. Strongly recommend that you choose and keep your tool as close to horizontal as possible. If you remember your vector forces, you know that steeper angles mean less support, and more power to the piece, not the turner.

You should try to ambush the wood, not chase it. If you ambush from a strongly prepared position where you have the fire support, angle and sweep over the battlefield, you'll gain an easy surrender. If you begin a hot pursuit by sliding without a bevel, you have lost everything, and open yourself up to ambush as you rush along uncontrolled.