Determine the figure you wish to sculpt. Draw the figure on a piece of paper.
Identify the main or largest parts of the figure. Correlate the largest parts in the figure to geometrical shapes that resemble each part. Parts of the metal sculpture may resemble the shape of a box, ball, cylinder, pyramid or other geometrically-shaped objects. For example, a sculpture of a human figure would need a round metal object for the head, a cylindrical object for its body, and long tubular pieces of metal for its limbs.
List all the parts on a piece of paper and number each one accordingly.
Determine the size (in inches) of the sculpture and write its approximate height and width along the horizontal and vertical sides of your drawing. Determine the approximate size of each main part of the figure and write the size alongside the part number.
Identify and list the other smaller parts of the sculpture that you might need. As an example, you need small pieces of metal that resemble the hands, ears, nose and eyes of a human figure.
Choose the size and form of the metal base. Commonly used bases are large metal objects that can be placed flat on the floor to support the weight of the sculpture and prevent it from toppling. Include the base in the parts list.
Acquire the parts you need for your metal sculpture by going to places where you can find junk-metal objects. Look for items that look similar in shape, form and size to the parts you need. Use metal cutting tools such as a hacksaw, angle grinder and acetylene torch if you need to cut metal to get the parts you need.
Cut pieces of metal into the desired pattern by marking the metal with welder's chalk and cutting along the line with an acetylene torch. Weld a steel rod or tube upright onto the metal base if you need a vertical means of supporting the parts.
Using the metal welding tool, attach the main pieces of the sculpture one by one, starting from the base, then moving to the tip of the sculpture.
Weld the smaller sculpture parts onto the main parts. Arrange the parts in a manner you think best expresses your artistic design. Use small steel bars if you need additional support when welding the parts together.
Remove rough metal edges using an angle grinder. Polish surfaces using sandpaper to reveal the natural color of the metal. For parts you wish to paint, sand the parts to remove rust and other particles, then paint. Allow the paint to dry before displaying your sculpture.