I also would suggest prepping parts and then renting a commercial air compressor. I priced the smaller sizes and you can rent one for about $250 bucks for the week.
And there shouldn't be any worry about blasting trough the frame if a regulator and patience is used. Only reason I even used a commercial air compressor was to save mine from running continously.
Make a list of the big parts that need blasting...prep them....and then set goals for the time that you have the compressor. Organize what has the most priority to you and then go after it. I got my frame and all the tins done in three days and left me plenty of time to work on the little stuff. Tarp helped recoup some of the sand costs.
