I get my sand in 5 gal buckets @ about 40 lbs ea. I think.
I'd guess a bag or two would get the frame done depending on how well you're able to reclaim what you shoot.
I sift the used sand through a window screen while blowing the shop vac across the 'stream of sand' as I dump it on the screen. It gets rid of a lot of the paint, dirt, etc that accumulates and makes a 'cloud of dust' the next time through.
Don't worry you'll get efficient before your 1/2 way through the frame... or take it to someone else!
