Bending Procedure

After a certain amount of trial and error, the recommended procedure divides the bending into a two step process. When a piece of conduit is bent in this jig, enough torque is developed to slightly rotate and reorient the tubing. This means that any holes pre drilled in the tubing for trellis wire loops and mounting screws may, and probably will, end up out of line with vineyard posts and canopy wires. The two step process eliminates this problem.

1. Use a 60" piece of exterior grade 1/2" electrical conduit. If a tubing cutter is used, there will be no sharp bur at the cut. If a hacksaw or chop saw is used, remove the bur with a round file (inside) and flat file (outside). Mark the center of the tubing (30"). Place the center of the tubing in alignment with your center mark on the back stop. Firmly press (tap with a block of wood if necessary) the tubing all the way to the work surface. Bend 90 degree angles at the #1 studs. This takes a bit of strength, and the jig should be clamped to a work bench or other surface. To increase your leverage, slide a 30" piece of 3/4" pipe over each "leg" to be bent. You should now have a U shape.

2. Remove the bent tubing from the jig. After carefully checking the diagram below for making and mounting trellis wire loops, mark, center punch and drill all holes for loops and the holes for mounting screws. A handy template for locating the loop holes may be made out of a split piece of 3/4" PVC.

3. Reinstall the tubing in the bending jig, aligning center marks on backstop and tube. Lift the "legs" over the #2 studs placing them inside these studs and press the tubing flat against the work surface. Bend the 45 degree angles on the #2 studs to create the short mounting arms for the spreader (use the pipe for leverage).bring both legs toward the center (they will bend easily) and align them with the lines marking the width of your vineyard posts. The Ingles spreader is ready for installation. You may need the leverage of a small pry bar to get it out of the jig. Wire loops may be installed at this point for pulling wire through an installed spreader, or the spreader may be installed on the vineyard post and the wire loops installed last.

Word of Caution: The conduit does not like to be bent more than once. If you make a mistake and try to straighten and re-bend a piece, you are likely to see cracks develop at the bends. The resultant loss of strength would dictate that this damaged material not be installed in the vineyard.
 

Footnote

(1) The jig described here was designed to supply multiple vineyard acres with Ingles spreaders. For limited applications, substituting plywood for the steel plate may suffice.
 

Drilling holes for Wire loops

Wire loops should be made of aluminum wire in the range of 10-14 ga. The lighter gauges are subject to damage by pruners who pull rather than cut tendrils that have entwined in the loops.