So we picked up one of these little portable sand blasters . It does what it says , it works great for small parts , i did a cantilever frame the other day using this for all the areas that were hard to get at with my 1/4" die grinder . It leaves a nice tooth in the metal for paint . It requires about 100-120 psi and 12 cfm , So you do need a nice size compressor to keep it going . The total price for the Speed Blaster , the Spot Blaster recovery kit (which I will get into later ) and shipping was about $100 . 
Here is a first attempt , it took the paint off with no sweat . The only sand i could get here was general purpose , which I had to sift to get the pea size gravel out , but regular playground sand should do fine .
Oh - one more note - you might want to use this outdoors unless you have a cabinet to do it in....
