Hollow Form Question

[Brent Dorner]

Just curious why people try to achieve such a narrow thickness to the walls of their hollow forms? I see some people trying to get 3/16-1/4 and I wonder why not go 3/8 or thicker? I would imagine with a narrow wall you would have a better change of blowing the piece up and I wonder why you wouldn't want more weight to the piece. So let me in on the secrets of the thin walls.... thanks.

[John Keeton]

Mystique!!! Brent, most of the HFs are relatively small, and part of the allure seems to be the unbelievably light weight of the object that draws the "oohs and ahhs". Most of my forms are under 6" in diameter, and I strive for 1/8" walls. 1/4" walls on such a form would make it both unsteady if on a pedestal, and too heavy in "feel" for a delicate finial.

[Tim Rinehart]

Brent, this is my spin on it (no pun intended...really). These are my opinions...so that and a buck may get you a cup of coffee.
Thinning down to a consistent thickness is important for a couple reasons. One is to make the form dry consistently (assume starting with green wood) and avoid goofy unintended distortion or cracking. I've left some of my pieces with really small feet a bit heavier on the bottom, for ballast, but that does carry some risk of differential drying/cracking. Two, I think this is where alot of turners want to be able to demonstrate tool control and technique by going thin and being consistent.
If you are planning on doing any sort of carving, or piercing, it becomes very important to have the ability to achieve specific thicknesses. If your piece has voids where it's possible to look inside, a thin wall usually looks better than a really thick wall.

All that being said, you have to balance thickness with size of piece and variables that could lead to a piece coming apart. Good sense has to prevail.

Edit after reading JK's comment: I completely agree especially on function where weight must be minimized (ornaments) you need to strive to make turning as thin as you can!

[Scott Hackler]

Yeah, what they said! Also this is (sometimes) a case similar to making very tight fitting lids on boxes. People who buy or receive the little boxes we make want a lid to just sit on top but woodturners seem to have an obssesion on very tight tolorences ...just to impress other turners! Along with that, anytime we hand a HF to another turner...if the hole is large enough... their finger goes right inside. One to check on how smooth the surface on the inside is and also to check thickness. Turners themselves, I believe, are way mroe impressed with a very thin wall than the average consumer. :) In some ways its a graduation to a higher skill level.

I thin as much as possible, but keep the project in mind. Christmas ornament = really thin, regular HF = pretty thin, pierced HF or vessel = 1/8" thick max, carving on the form = 1/4"....or so.

[Jim Burr]

The guy who taught me is pretty famous...he does gallerys, shows, been published on calenders and in print. When I saw his stuff in person, I expected paper thin. I was surprised the actual thickness was about 1/4". Some where thinner, but most not. I asked him what the reason is that people turn stuff so thin. "To impress other turners" was his answer. Joe sixpack has no idea if it's cool or not. As long as the inside is finished, it shouldn't matter...with certain exceptions of course...voids, method of display...so on.

[Jamie Donaldson]

A vessel wall thicknes of 1/4" or thicker if a bit of a risk for many woods turned green, as the movement stresses during drying are greatly reduced by going a bit thinner. Jim is right that many turners go thin just because we can, to show other turners that our skills are up to snuff, but thin is "in" for green wood vessels for a good reason-survival!

[Josh Bowman]

Brent,
My wife says the same thing. I guess, because we can.......sometimes.

[Steve Kubien]

I am of the opinion that an CONSISTANT wall thickness is more important than ultra-thin. Mostly, I think it is done to impress other turners and collectors of wood art. If that is your target market, then you better play the game. That Keaton guy has a good point as well... Some forms/styles of turnings (like pedestal-ed hollow forms) would be unbalanced and tippy if much thicker than 3/16"

The challenge of going thin certainly appeals to a lot of turners. I'm generally not one of them. 95% of the hollow forms I do are for cremation urns. 1/8" thickness don't mean squat in that scenario.

But that is all just my opinion...

[David E Keller]

In addition to the reasons already mentioned, sometimes it's fun to go thin just for the challenge! Hollowing can be pretty mundane, but if you try to get 1/8" walls in a $100 burl... Well, that can be downright exciting!

[Bernie Weishapl]

I have to agree with Tim and Steve K. I take them down as thin as I can for a more even drying of the vessel. When I slosh oil on the inside I like it bleed to the outside. Seems to keep them from much warping and cracking.

[Wally Dickerman]

There are several reasons to turn thin or not. As Jamie said, if you're turning wet wood turning thin helps to prevent cracking. I became fascininated with turning thin by watching Del Stubbs turning his very thin pieces back in the 80's. Most of my HF's are thin walled because that's what I enjoy doing. I do quite a bit of pyrography. I learned the hard way to not turn them too thin. I was buring a design onto a thin walled piece and making lots of smoke as usual. Suddenly I realized that a lot of the smoke was coming from the inside of the piece....yep, my vessel was on fire. I put the fire out with my bottle of drinking water and tossed the piece in the trash.:confused:

This afternoon I put a first coat of finish on a pierced pieced that I had finished this morning. In order to do the piercing the walls must be 1/16th inch. Any thicker will give me problems. (I'll post a pic of the piece in a few days)

I've had feedback from galleries that some of my pieces sell because buyers enjoy the lightweight feel of them.

Turning thin is usually just a matter of choice.

[Alan Trout]

I like to turn thin as possible as a challenge for myself. I like picking up a large vessel and think to myself "Wow that weights nothing". For me it is part of the enjoyment of making the piece.

Alan

[Rich Aldrich]

I always thought it was bragging rights:eek: - no offense intended:). Hopefully in a few months I will be set up with some sort of Monster to hollow. In the mean time, I am going to try with some hand tools.