I was successful in blowing the dirt and water out of a 200' run of 1.25 RNC using a gadget I originally made for an air cannon. I brazed a 3/4" NPT nipple into a freon jug and screwed a ball valve on it. For the cannon, it was capable of sending an orange out of sight but when I turned this over to blowing out the RNC it worked great. I put about 100 PSI of air in it, hooked it to the RNC and let it fly. Dirt, water and mist went about 50' but the pipe was cleaned out. It worked so well I filled the pipe up with fresh water and "shot" it again. just to get the last of the sand out.
Then I blew some soap in there and the wires just sailed through.
