For rockets of the size that I fly, most of my final painting is done with cans of spray paint. For the real big rockets, people either use automotive paint guns or take the rocket to a local auto-paint shop. Sometimes you can make a deal where they'll paint your rocket for a reduced price if they can use up leftover paint from another job.
The most interesting finish I've ever seen on a big rocket didn't use paint at all. One guy laminated uncut sheets of US one dollar bills (info available here on how to get them) onto his rocket. I remember it took just over one hundred bills to cover the entire airframe, and he said it was actually a bit cheaper than taking it into the shop for a professional paint job.
Posted by Ted at November 7, 2003 09:29 PM