went into harbor freight the other day and was looking though the sprayers they had... not a ton in stock but a few that would do the job including a 15 gallon one (i figure could be good for large comm jobs... but looked today online and found a few others specifcly this one...
almost 5 gallons,
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94573
* Continuous 8 hour runtime on a full charge
* Spray up to 20 gallons before recharging
* 4.8 gallon tank capacity
* Low maintenance diaphragm pump
* Triple screen filtration keeps nozzle from clogging
* Nozzle adjusts to 4x stream, mist, conical spray, dual 30 degree spray
* Rust-free ABS construction with nylon web straps
* Built-in wheels for smooth rolling on level surfaces
as for the large one...
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=9583
there is also a larger one (25gal) for about 150... you'd need to rig up some sort of easily rolling system for it but for large jobs i can see somone having use for these... and they are all cheaper then the others i've seen
More practical, I think, are the 5-gallon electric sprayers from Rocket Spray (www.rocketspray.com). They come with wheels already attached. Reasonably priced also.
I have purchased both the standard and the HD rocket sprayer. I prefer the HD version. has twice the psi, which measns I can move faster when prespraying. Also has better wheels and a larger battery. Both will go 50 gallons between charges.
