Back Hollowing?

[PheasantHunter]

I have watched Richard Raffin's box turning DVD multiple times. However, I still don't understand his backhollowing technique for cutting end grain. Can anyone explain how this is done?

 

[American & Proud]

Take a L00K here there are some Vids. Scroll 2/3rds down the page to find.
http://www.hiltonhandcraft.com/woodturningvideos.asp

 

[john lucas]

I have tried it. I find it very difficult but then I haven't practiced it much. I find hollowing end grain with the Hunter tool much easier and gives an extremely clean finish. He does show it in his box turning video but it's something that requires a lot of practice on scrap. The catches are quite spectacular so you don't want to try it on something you want to save.

 

[James McClure]

I agree with John.

You can hurt yourself with this cut if you are not careful.

 

[Malcolm Smith]

Definately takes some practice. Quick, but really a technique that's more suitable for someone who frequently uses it and is watching the clock.

Malcolm Smith.

 

[Ron Sardo]

While not an expert on this, I have used this cut a few times. It is scary at first, but it is a cut worth learning.

 

[GeorgeH]

I have to agree with Malcolm's comment about this approach to hollowing being useful to those who are "watching the clock". I use the technique only when I need to remove a lot of material quickly. For that purpose, it works very well. But it has its drawbacks and if I had never learned it I can't say that I'd be any less effective at hollowing.
It's simply a technique and, contrary to some commentary on the practice, there's really no "trick" to it. Learning to use this method for removing material requires using a very small section of the cutting edge, consistently, throughout the cut. There is no margin for error and, if the turner looses concentration for an instant, it's all over.
My suggestion would be, if you're not involved in production work where you've got to meet specific quotas, use the traditional methods for hollowing with the bowl gouge and forget about this one.

 

[MichaelMouse]

Take a L00K here there are some Vids. Scroll 2/3rds down the page to find.
http://www.hiltonhandcraft.com/woodturningvideos.asp

The alternative he demonstrates following the back cut video is similar to the cut I use for the purpose. Difference being I use a pointy-ground gouge which bites better on the plunge without skating, and hog with the side of that tool going both outward and inward. Those familiar with Oland tools will recognize the principle involved. It can hollow very aggressively, but the strain of cutting is taken downward on the rest rather than on the turner's wrists. I then finish the cut using a conventionally fingernailed gouge as Andrew demonstrates. Sometimes I will do the very bottom with my Termite, but using the gouge allows me to set the rest slightly below center, where the shavings evolve down the flute and get out of the way, rather than being trapped as with the Termite.

As you can see by the form of the shavings, they are thicker toward the rim and feathered toward the rear, which allows for a pretty good side cut even when hogging.

 

[Captain Eddie]

I've seen a video by Dennis White where he goes from the 7:00 position to the 2:00 position without pausing. He hollowed an entire bowl this way. Maybe that's what 50 years of production teaches you - there are no rules.

 

[Steve Worcester]

You can hurt yourself with this cut if you are not careful.

You can hurt yourself with anything done improperly. My basic philosophy for woodturning is
there is no right way or wrong way to do it, just some that are more safe than others.

 

[Ken Grunke]

I taught myself the technique about 15 years ago and still use it once in a while for hollowing out small boxes and also trumpet vases. If you understand the mechanics of the technique, it's not all that hard or risky. I'm not a production turner so don't use it very often but I'm glad I figured it out back then, as it comes in handy on occasion.

You cut with the flute facing away from yourself, a bit upwards, and with the top wing. A pre-drilled hole is very helpful. The main trick is using the vessel's opening as a fulcrum to lever the gouge into the cut. You control the bite of the gouge's edge by twirling it on it's axis to keep it from biting in and grabbing--and adjusting that axial position as you advance the cut outwards, to keep the bevel rubbing properly just like any other gouge or skew cut.

A drastically swept-back grind on a gouge tends to make the cut too aggressive and hard to control on this technique. My gouges had only a small amount of sweep-back on the edges until about 5 years ago, when I started using the Ellsworth grinding jig. The Ellsworth grind works fine for the cone-shaped hollowing I do on my trumpet vases, but for hollowing lidded boxes I now use a hook tool or the Berger tool.

If my explanation needs more clarification, just ask. I would take some pics or even a video but it would have to wait a week or so until I get back home from a visit/workstay on my sister's dairy farm. Raffan's backhollowing technique can remove a lot of shavings quickly from a small box or any hollow vessel with an opening no smaller than it's interior.

 

[hockenbery]

This is a useful technique.

This is a great example of a technique you can learn or teach others at club demos. A few years ago the Chesapeake woodturnes did all day demos at a Christmas shop in a Behnkes nursery. Someone asked about back hollowing. Temple Backwood held a mini class and three novices were cranking out goblets using the back hollowing the rest of the morning. I'm sure they have that skill for life.

happy Turning,
Al