I generally don't fool with plumbing (too wet) or electricity (too shocking) but Amy asked if I could replace a ceiling light fixture in her kitchen and install a garbage disposal. I said sure, because how hard could either of those tasks be? Pull the old light fixture off, attach the wires to the new one, and fasten it to the outlet box (or whatever it's called). I had done three or four garbage disposals before, and those were also not hard: put in the drain, attach the disposal to it, plug in the power cord to the convenient under-sink outlet, and run the outlet tube into the drain pipe. Half hour each, right? Wrong--more like 16 hours total.
The existing light fixture was a four-foot fluorescent more typical of an office building. No wonder Amy wanted it down. First, I had to figure how to get the cover off so I could unbolt it from its moorings. There were two slot-head bolts (ugh) at either end and, even holding a cordless drill above my head, it seemed to take forever to undo the six inch toggle bolts. I got the fixture down in one piece without breaking a tube and unleashing mercury vapors. There was a ragged hole about where the outlet box would go and a pipe and strap above it. There would be no screwing the box into a joist--the nearest one was a foot away. I couldn't use a hanger bar-- the pipe was in the way. I got a metal strap, snaked it over the bar and bolted the outlet box to the strap. Then it was spackle fest time as I filled in the gaps around the box. That of course took several applications but I got it smooth and level and wired the lamp head to the ceiling wires, hung the head, screwed in the bulbs and put on the shade. It worked the first time! I put a coat of paint on the unpainted area and then it was on to task # 2.
Every other disposal I have installed went into a space with a wired plugin box and a drain that came out of the wall at the back of the space. This installation had a roughed in outlet (i.e. wires in a wall outlet box) and wires in a switch box above the counter. The drain line came in from the side of the cabinet, sloping downward as it approached the disposal site. I couldn't figure out what I needed for the plumbing so I took all the pertinent pipes out, went to Rice's Hardware (a heavenly place), dumped my collection of pipe on the counter and said, "Help! Please tell me what I need."
I described the installation and showed them my diagram of what I had. One of the Rice brothers plucked several pieces from the plastic pipe bins, showed me how it should be configured and sent me on my merry way. I put the pipes together and other than a couple of flanges in the way, it worked fine. I tightened everything up and ran some water through the pipes, tightened everything up. In recutting and attaching the hose from the air gap to the disposal I managed to break the plastic part of the air gap so it was back to Rice's for another. There seemed to be great interest in my project by this time.
When I ran water through the drain, there were some definite leaks. I tightened everything up and noticed that one of the flanges was skewing a pipe joint, unsealing it and causing the leak. The disposal drain tube needed lengthening, so back to Rice's I went. With the drain tube longer, the pipes were water tight.
Next step was to install an outlet and a switch. The outlet was under the sink at the back of the space, so I spent a pleasant time lying on my stomach attaching wires and putting them into the box and bolting the cover on,. The switch went more easily. I turned the breaker back on and threw the disposal switch. Nothing. I checked the breaker panel and saw the disposal breaker had thrown. I had a short somewhere. So it was back under the sink where I found a hot wire had come loose and was shorting itself out against the metal box. I reattached it and tried again. No luck. I pulled the switch wires out and found a wire had come loose. With that reattached, it worked! I wished I had something to grind up but I didn't.
The last trip to Rice's was for a switch plate. The crew there practically applauded when I told them it was the last thing I needed for the project. I had worked with a couple of breaks from 9:30 until 5:30 on these two simple additions in addition to about eight hours during the week of prep time. OK, I'm slow.
Plumbers and electricians are paid well, and I'm here to tell you they earn very cent of it. Just don't try this at home unless you have a lot of time and are full up of patience.