More great stuff. 

For future reference, I use these elastic moving bands for odd shapes that are difficult to clamp.  Just cut them to open.  By stretching as you wind them around your workpiece they apply even pressure.  I've used stretch wrap too but when I need more clamping pressure these are my go to clamps.  I usually just use spring clamps to hold the ends but wrapping the end over itself adds some insurance.   

--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.