Is it possible to make a bend this sharp with out crushing this 1/2'' tubing? Not sure how thick the tubing is, but here's a picture to give you an idea. I have a tube bender that will make the right degree bend, but not nearly as sharp as I want it. I made a template out of wood so I have something to bend it along, but the tube just ends up crushing.
If you use sand , Make sure it is dry! Any moisture in it can explode the pipe. It will work , but has tobe packed Tight and sealed well.
I don't think there is anything you can do to get that tight a bend, I don't care what is used to pack it! You can probably find some tight bends at www.aircraftspruce.com
I wouldn't do any of above. If you want a basic square corner in same radius as the tube go to a bearing house and buy loose 1/2" steel balls and weld it to the tube. You can't make a better corner than that. If your going to chrome it then braze it together not wire weld. The Wizzard