You’ve got love simple hacks like this that give you access a tool you don’t otherwise have or can’t afford. Adam Fleisch modified $5 Harbor Freight airgun and a .77 fitting and a soda bottle to create a super-cheap but what appears to be effective sandblaster gun.

The only really futzy part was creating the 1/2″ feed hole in the blower tube using a grinding wheel. But that can be easily done. Then it’s just a matter of drilling a hole through the soda bottle, filling it was blast medium, and firing away. Not sure how robust this solution is, but for a one-time or periodic blasting work, I’d imagine this would work just fine. It certainly wouldn’t cost a lot, in money or time, to find out.

Here is Fleisch’s full Instructable.