Spiculums

Lesson: Spiculums

Spiculum are tube shapes that taper toward one end or both. These can be used in jewelry or sculpture and the look of the spiculum can be altered quite a bit by playing with the width and the length. Shorter spiculums are reminiscent of pod forms, while longer ones are more quill-like and spiky.

• Create your pattern out of paper. Make sure that the tapers are the same- fold the pattern along the vertical axis to check.
• Width= circumference + (2 x metal thickness)
• Circumference= 3.14 x diameter
• If you want a spiculum that is 8 mm in diameter, the circumference is 25.12mm
• Using 24ga metal, add 1.2mm (2 x .511 mm) to the circumference for a width of 26.3mm
• Cut your pattern out of metal- 20-24ga.
• Anneal. File the edges clean.
• Mark a line down the vertical axis with a sharpie
• Use the wooden blocks and a cross peen mallet or hammer face to begin forming the metal into a U shape. Hit along your line. This helps to keep your edges straight. If you start twisting, pull the metal to untwist the seam and retry.
• Rotate your U in the block and begin curling the sides of the U into more of a C.
• Using a mallet, work the outside of the shape, aiming for a round profile all the way through.
• You can rest your spiculum on the steel blocks for more support, or the wood for a softer surface.
• Slowly bring the edges of the seam together, there should be a very slight angle.
• Using a planishing hammer, hit directly along the seam, rounding and truing up where the edges meet.
• Be careful not to go completely horizontal where the edges meet or beyond. This can cause divots in the surface of the spiculum which once closed are very difficult to get out.
• Solder seam closed.