basic shapes...

[drthulium]

I like talking about technique (I guess i am a process oriented person at heart!)
so in that vien, some thing I have played with for some years, but never found a solution I really like, is:
Does anyone know of a good way to make spheres out of welded sheet metal?

There are lots of ways I have tried, hammering, making sections, etc... but it is always a lot of work and not so consistent in execution.

Nate

[Araich]

What about joining gas/liquid tank ends?

The steel ball is an element I use often on a small scale, but I also would love large steel balls (no joke).

The only ones I've ever seen are cast, and for use in shipping, or buoys.

[JHoughton]

Scrap metal yards are great for those. A fellow sculpture and I found three old propane? tanks for close to nothing. Many hours of rust and dent removal was payment enough.

[cote]

I like talking about technique (I guess i am a process oriented person at heart!)
so in that vien, some thing I have played with for some years, but never found a solution I really like, is:
Does anyone know of a good way to make spheres out of welded sheet metal?

There are lots of ways I have tried, hammering, making sections, etc... but it is always a lot of work and not so consistent in execution.

Nate
There are two practical methods of making true (hemi)spheres out of sheet metal that I am aware of. For small to medium size pieces Metal Spinning is the technique most often used. Explosion (Concussion) Forming is a practical and cost effective way to produce large scale pieces.

If you would like to discuss this further, please don't hesitate to give me a call.

Best Regards
Greg Pettengill
Cote' Art & Engineering
321-269-7587

[sculptorsam]

I'll second (or third) using propane/natural gas tank ends for a relatively easy solution. You should be able to find a decent selection of sizes, and up to around 3 feet in diameter if you use a natural gas tank. If you plan on making a large number of them, setting up for the methods mentioned by Greg would be a good long-term solution. For really small spheres, and if you have access to a brake and a crazy blacksmithing friend, you could look at getting a custom die made to pound out halves. Just a thought.

Good luck.

Sam

[RuBert]

I have generated here a basic half-spherical form.

Metal can be cut, then slightly dished, then welded together to form larger spheres than other methods would allow.

[ironman]

there is a company in texas that makes ornamental iron stuff including spheres in steel, stainless and other metals, and in different sizes. The name escapes me at the moment and I'll post another reply when I get that info. They also sell 1/2 spheres and a lot of other ornamental stuff.

[jsimms]

I've gotten spheres and hemispheres up to 12" dia x 11ga. from Braun
( http://www.jgbraun.com/balls.html ) in various metals. Very nice, I believe hydro formed. Used to get silicon bronze 12" hemis for about $60, but I think they've gone way up in price. Steel is still pretty cheap, or was until a year or so ago.
john

http://www.jgbraun.com/balls.html

[ironman]

Hi, I'm back, the company in texas that makes hollow steel balls is King Supply Co. They have offices in Dallas and Baltimore and their # is 1-800-542-2379. Their web site is www.kingsupplyco.com, it is an older catalog so the info could be wrong. The only drawback as far as I can tell is that you are limited in size to a max. of 12" diam. According to them they supply the ornamental iron and architectual metal industries, nationwide. This might be a place to start. Another way might be to start with a piece of pipe about the diameter of the ball that you want and cut rings out of the pipe. Once you cut the second ring you'll have to adopt it to the first and so on. I've never tried that and I don't think you'll get a perfect ball this way but a faceted one that may or may not meet your needs.