Instead of using 90 degree PVC elbows, which have an abrupt change of
direction, consider using PVC 'sweeps'... These PVC components spread the 90
degree turn over a very wide area, minimizing stress at the antenna's corners.
The larger the diameter, the greater the sweep. I use 2 inch sweeps and
mount an eye-bolt at the outside of the apex, for support.
This provides a very gentle curve for the antenna wire. Sweeps are available
at Home Depot or similar outlets.
Never be afraid to try something new.
Remember, amateurs built the ark,
professionals built the Titanic...
...73, Larry, W1GOR