Vic Barkas wrote:

Hello group,

I am sort of a novice metal sculptor. I work mostly with the
oxy-acetylene torch, some modest blacksmithing equipment, a drill
press, grinder, band saw and the usual small hand and power tools.

My question is, what are some suggestions for making a smallish hollow
steel sphere without my inversting a bunch more in tools, such as a
lathe? I am talking about a sphere the size of a baseball.

YOu can dish steel sheet to a sphere, and then use raising techniques
over a stake to take it to almost a complete sphere, if having an
opening is ok. All you need are hammers and a ball stake.

What you describe below is dishing, but you don't need to do it hot
(it does make it easier.) Using hammers with a face radius similar to
the final result you want will make it easier.

Since two hemispheres are ok. get to the point where you have dished
it close, and then put it over a ball of some sort, and start
planishing it closer to your final shape.



Two approiaches I have considered are building it up with rings of
sheet metal, perhaps 1/2 inch wide, and welding them, as like lines of
lingitude on a globe. Pretty tedious. The other method I have
experimented a little with is heating up a 1/16" thick sheet red hot
and pounding it into the open end of a large piece of pipe with the
ball end of a ball pein hammer. I found it somewhat difficult to get
a full hemisphere by this method, and it is also quite possible to
hole the dome with hammer blows. The plan was to create two
hemispheres and weld them together.

Any thoughts? A perfect geometric sphere is not essential.

jk