I've got a fogwill pump box that we use when we need to do any windows. It works well for what we need it for but im wanting to build another pump box for using chemicals etc. I have looked at the box Mark from here built and am looking at building something similar. I popped open the fogwill box, and noticed it had a relay inside it. Its pretty basic, relay, pump, switch hoses etc.
Marks box didnt have a relay in it, and i was just wondering if the relay is really needed? I was just going to use a shurflo pump ive got lying around, and buy a controller like Mark uses, and plumb it all in with an on/off switch. Do i need a really? Why would the Fogwill box have a relay in it?
Cheers
Matt