Tiny entry holes on Hollow Forms

[Burt Alcantara]

The videos I've seen always demonstrate hollowing with a large entry hole, be it by hand or system. The only reference I've seen was to hollow from the bottom.

I'd appreciate any tips, pointers, DVDs, web sites, books or otherwise to get me up to speed. I've viewed the Jamieson and Mahoney DVDs on hollowing but I'd still like more info.

My other confusion is about boring bars and bits. Can any bit fit any bar?

Thanks,
Burt

 

[john lucas]

burt It's fairly easy to turn through the bottom. I cut out a plug and try to save it so that I can dry it and put it back in the hole later. Learned this from John Jordan many years ago. I simply mount the piece on a faceplate and turn the shape leaving the upper lip (which is now the bottom) for last. You want the thickness there while hollowing. When I finish hollowing I shape the lip.
Not all cutters fit all boring bars. you have to read the fine print. Many of the boring bars will take a 3/16 square bit or a 1/4" round bit. The other ones can be odd shaped.

 

[George Guadiane]

The videos I've seen always demonstrate hollowing with a large entry hole, be it by hand or system. The only reference I've seen was to hollow from the bottom.

I'd appreciate any tips, pointers, DVDs, web sites, books or otherwise to get me up to speed. I've viewed the Jamieson and Mahoney DVDs on hollowing but I'd still like more info.

My other confusion is about boring bars and bits. Can any bit fit any bar?

Thanks,
Burt

Hey Burt, I'm not sure what you mean by "large" entry holes...
I hollow through the top on most of my stuff, using a 1 inch hole. Anything much smaller than that is either done through the bottom or as a 2 part hollow form, you know the ones with the three burned bands around the wide point.
I think the videos are done with larger openings to give their students an easier path to success.
As I started hollowing, I started with a larger hole and got the form down (sort of), then made the same general form with an increasingly smaller opening. If you get a pleasing outcome, you did it right... I'm not one of those who thinks that you MUST hollow through the top ONLY to have a hollow form. You're not really selling technique, your selling outcome. We don't really care how you made the pie, just that it tastes good!

 

[Ed Koenig]

burt It's fairly easy to turn through the bottom. I cut out a plug and try to save it so that I can dry it and put it back in the hole later. Learned this from John Jordan many years ago.

John, I'm curious how you cut a plug from a solid piece of wood and than use it in the same hole without any loss of wood from cutting? It seems to me that your hole will be larger than your plug.

 

[Steve Worcester]

Smaller entry holes are done just the same, but with smaller tools, more time and more patience. It is pretty much just the same. One difference is that it becomes more difficult as the piece gets larger because of the smaller diameter tools.

 

[john lucas]

Ed When I start the piece between centers I turn a tenon for either the faceplate or chuck. Then I use a parting tool and cut then end off. I put this in a plastic bag and reverse the bag every day. This dries the plug very slowly so it doesn't check. The grain doesn't always match perfectly because of the space between the end and the eventual bottom of the piece but it's usually close enough that only I know.
After I turn the piece through the bottom I let it dry and warp. The hole in the bottom usually warps of course. I will either drill it out so it's round, or carve it round. Usually I just take a forestner bit and twist it by hand to mark a circle. then I carve this out with tapered sides. Then I'll glue the plug to a waste block and turn it close to the size with a taper that matches the hole I carved. then it's just a matter of glueing the plug in the hole and carving away the waste.

 

[Ed Koenig]

Ed When I start the piece between centers I turn a tenon for either the faceplate or chuck. Then I use a parting tool and cut then end off. I put this in a plastic bag and reverse the bag every day. This dries the plug very slowly so it doesn't check. The grain doesn't always match perfectly because of the space between the end and the eventual bottom of the piece but it's usually close enough that only I know.
After I turn the piece through the bottom I let it dry and warp. The hole in the bottom usually warps of course. I will either drill it out so it's round, or carve it round. Usually I just take a forestner bit and twist it by hand to mark a circle. then I carve this out with tapered sides. Then I'll glue the plug to a waste block and turn it close to the size with a taper that matches the hole I carved. then it's just a matter of glueing the plug in the hole and carving away the waste.

John, thank you for the great explanation. I understand exactly what you do now. As you may know, I turn a fair amount of HF's through small openings but I have never done any through the bottom. I enjoy the challange working through the top but I will give your method a try on my next large form. Thanks again for the tip.
Ed

 

[john lucas]

Ed I like to do that on small hollow forms so I can leave a hole about 3/8" on the top to throw off the customers. On larger forms I usually go through the top also.

 

[Burt Alcantara]

One other thing: do you turn your HFs green or dry?

Thanks,
Burt

 

[john lucas]

Burt I turn all large hollow forms green. I will turn dry wood but I rarely have any larger than about 6" in diameter.

 

[Burt Alcantara]

I recently rented "Tools for Hollow Turning," i.e., the "T Tape" by David Ellsworth. He shows a hollow form that he created early on in his career. This form had a top opening of about 2.5" or so. Next to this form was a diskoid with an opening that looked to be 3/4". He said this was made after he got the knack of it.

I have a feeling that with his skill, he probably whipped it out thru the top in a matter of minutes. The video continues with a very detailed view (through a cut-away form) of tool placement - the good and the bad.

However, he doesn't talk about the tiny opening again.

I'm still on the fence regarding tools and captured systems. A few threads back there was mention of a new elbo like tool due around November. I'm wondering if captured systems can deal with tiny openings through the top (as if it matters at all...).

I don't want to spend the next 5 years learning how to manually hollow a vessel. Is digging a hole art? How about a coring system for hollow forms?

Burt

 

[john lucas]

Burt Hollowing is really just practice. It doesn't take that long to learn but professional instruction sure helps speed up the process. Start with small vessels and work your way up to larger ones.
You do lose a little versatility using captured bar systems but they also take a lot of the fear our of hollowing. I find that i have to change to different shaped hollowing tools more often with the captured bar systems but it depends entirely on the shape of your vesssel. Many vessels can be turned easily with just a straight bar and one curved bar, by hand or with the captured bar systems.
I like the john Jordan or David Ellsworth systems because they are so simple and work very well.