Heatbending and Heatshrinking. Light, Coiled And Lyrical. Part III
CLOSEUP OF TIGHT RADIUS BEND PENDANT, COMPARED TO SINGLE AND DOUBLE TIGHT RADIUS BEND EARRINGS; the one on the right is an older pair, made from bamboo harvested and dried for a long period, versus two Coverlite adorned ones on the left which are from freshly culled culms. The positioning of the wire matrix results in either horizontally or vertically oriented panels of red. Both have decorations of red precious coral and sterling silver beads, as well as hand-formed/forged silver earwires. The older example has vintage Bohemian glass, and Ethiopian silver beads for decorations. Earrings are 9.5 - 12.2 cm long.
With the current drought in California, many plants are suffering. I have lost one species of clumping bamboo, another is threatened and my favorite black bamboo is not doing well, with many plants of the grove dying. I am able to cull some of the dying plants before they change to the point where they are not useful for jewelry but others are too far gone. This has prompted me to prune a few thin culms off those struggling but still live grasses, to see how they will heat bend while still fresh. Most were of so small a diameter I would not have used them in the past, except perhaps for intertwined torques or earrings (Liu 2012).
Of the two batches I culled, one was used about a day after cutting; when heated with an acetylene or Orca propane/air torch, these bent very easily around a small diameter wood dowel held upright in a vise. As seen in the first photo of this blog, some were single tight radius bends, others double tight radius bends. Still others were bent into circles at both ends, to act as pendants, with the top bend serving as the bail. In a second batch, used the day after also, the bamboo was still too laden with moisture, so that it was necessary to twist fine copper wire around the bends, to keep them from springing apart after heating and cooling.
These tight radius bend black bamboo components were used as a pendant on an intertwined torque, and two styles of earrings. I felt the bends from freshly culled bamboo had that wonderful lyrical feel reminiscent of plant growth and form that I try to capture in my jewelry. In order to add the color that is suggestive of flowers, or seed pods, I integrated square wire matrices into the bamboo bends, then attached red Coverlite. Since model airplane coverings are films and not fabrics, they do not drape or fit well into small crevices or discontinuities. Therefore when you are working with Coverlite or similar materials, you have to keep gaps to a minimum. In order for such polyester films to really heatshrink, every attachment surface must be uniformly glued. When glued and heatshrunk, this model airplane covering brings both color and pleasing geometric planes into play for these very light, yet strong earrings.
While all of these torques and earrings look fairly easy to make, they in fact require a great deal of work, since no two are really alike, due to the natural variation in both the form/size of the bamboo and how it reacts to heatbending. So time-consuming adjustments have to be made to each piece, rendering each finished jewelry one-of-a-kind.
FRESHLY CUT, THIN BLACK BAMBOO CULMS that were heatbent with a torch about a day or so after culling. A broom handle mandrel was used, to make these single and double tight radius bends. Those on the left were from a batch that still had too much moisture, so the bends needed to be tied with thin copper wire to hold their shape until they dried more. The diameters of the bends were 3.5-3.8 cm.
HEATBENT DOUBLE TIGHT RADIUS BEND CULMS in process of being made into earrings. One of pair has square 18 gauge bronze wire matrix fitted to bent bamboo circle. One end of wire fits into drilled hole, other into a slot filed in upper part of circle. Finished example in last image of blog. Note thin copper wire holding bent bamboo in place while piece is being worked.
COVERLITE GLUED in place but not yet trimmed before heatshrinking. Trimming results in better heatshrinking, reducing crinkling and also eases cleanup.
SINGLE TIGHT RADIUS BEND EARRINGS, with heatshrunk Coverlite on wire matrix, precious coral and sterling silver bead terminations and 18 gauge sterling silver earwire, handformed, forged and buffed. In this type of earring, both ends of the wire matrix are in drilled holes, which are glued into place; ca. 9.5 cm long. Open end of silver earwire worn toward head.
SQUARE BEND TORQUE WITH FOSSIL SHARK TOOTH VS INTERTWINED TORQUE AND PENDANT, latter with freshly cut black bamboo culms. Note how tight the intertwining, as well as the bail of the pendant is also a tight radius bend. This torque is decorated with vintage Bohemian glass rings and beads from the African trade, and Baule brass bead terminations. The 45-70 million years old fossil Lamna shark tooth from Morocco is accentuated with two Cornaline d’ Allepo Venetian beads, which simulate the way Polynesians use red sealing wax to decorate their shark tooth jewelry. The tooth is attached to the bamboo with wrapped, annealed square bronze wire. All photographs by Robert K. Liu/Ornament.
