Well, the instructions say daily... :)
Alot of it depends on how humid your enviroment is, but I'd say at least weekly. Commercial trucks that use airbrakes have a good system that you might want to look into. The drain valve is on a spring with a cable connected to it. All a driver needs to do to drain their air tanks is pull that cable for a few seconds, and when they release it the spring pulls the plug back into a sealed posistion. I'm not sure where you'd pick up the hardware for that, but if you can't find it anywhere else I'm sure you could get one of those valves from any heavy duty truck mechanic, repair shop, or dealer.
I have head my compressor for several months and have never opened the
> drain plug, as to be honest, I didn't expect if to contain and water. >
> TOday, I decided to open it and was surprised that a fair bit of brown
> coloured water came out!
>
> I then checked the instructions and it says that I should be doing > this DAILY! >
> THe compressor stays permenantly charged, and probably gets used a few > times a month.
>
> Realistically, how often should I drain it as daily in impossible and > impracticle! >
> Does condenstation only form during the time that the pump is charging
> the tank? If so, should I only need to drain the water after it
> actually been filled.
>
> If the tank stays full of air and nothing goes in or out, is there any
> need to drain condenstation?
>
> Any info on this would be appreciated.
>
> Jon