What's the definition of a Hollow Form?

[Brian Kent]

I know if there is a sphere with 1/64" walls and a 3/4" hole, that's a Hollow Form.

But what about a 10" wide bowl with a 4" opening and 3/8" walls?

What about a 10" calabash bowl with an 8" inside rim?

Where do you start calling it a hollow form?

[Prashun Patel]

Personally, I think anything with a convex and nested concave side is a hollow form. That name refers to the form.

Bowls, vases, and vessels refer to function.

I always thought bowls, vases, and vessels were a subset of hollow forms.

[charlie knighton]

depends on the turner who did the form, his call, put it in gallery, its the curater who makes the call, whoever is the boss man

[Thom Sturgill]

Good question Brian! I suppose that technically any form with the opening smaller than the widest part of the interior is a HF, I hesitate to call a typical calabash a HF.

Maybe when the opening is small enough that the turner can not see the inside while turning? That would make your 10" form with a 4" opening a HF and I am comfortable with that description.

[Brian Kent]

Good question Brian! I suppose that technically any form with the opening smaller than the widest part of the interior is a HF, I hesitate to call a typical calabash a HF.

Maybe when the opening is small enough that the turner can not see the inside while turning? That would make your 10" form with a 4" opening a HF and I am comfortable with that description.

I like that distinction. Thanks

[John Keeton]

A "closed form" is a form that has a mouth smaller than the maximum diameter of the form, and somewhere along the line as the mouth becomes smaller, folks use the term hollow form. As has been indicated, that nomenclature will vary depending on who is involved. Typically, I would think most hollow forms involve an opening of 2" or less.

[Curt Fuller]

Once you step outside the woodturning realm most people would look at you kind of funny for even talking about a hollowform.;) Likewise when you talk about wall thickness. But I think Thom and John's descriptions are pretty close.

[Brian Kent]

Once you step outside the woodturning realm most people would look at you kind of funny for even talking about a hollowform.;) Likewise when you talk about wall thickness. But I think Thom and John's descriptions are pretty close.

It wasn't long ago that I thought HF meant Harbor Freight.

[Thom Sturgill]

It wasn't long ago that I thought HF meant Harbor Freight.

It does. Just depends on the context.:)