Plumbing is not my forte, and this weekend I had a DIYsaster. I finally removed my bathroom sink, which looked like it had been caulked by a blind man, scraped both sink and wall clean with razor, then re-installed and re-caulked. While I was at it I swapped out the faucet too—but once everything was hooked back up, I discovered the shut-off valves for the water were shot. I'd probably overtightened them during the shut-off and cracked the seals.
To replace them you've gotta cut the old valves off at the pipes then re-install new valves, losing a couple inches of pipe, which I can spare. But the smallest pipe cutter I own is five inches long:
Problem is, the pipe to be cut is only two inches away from the wall. Not enough room to rotate the tool to make the cut.
I'm not the first to experience this problem, of course, and after researching I found some clever tool designer has already solved it by creating a single-handed pipe cutter. The AutoCut is one example, though a bunch of companies make them.
You snap the circular ring around the pipe and rotate it, causing the blades to close in with each turn. The compact shape means you can get it into the tightest of spaces, and they sell a ratcheting attachment if you need more leverage.
Once you've got the pipe cut, you need to clean the freshly-trimmed edge so you can get a good seal with the valve. This is another area where tight space is a problem; I'm not going to be able to do a sandpaper-strip shoeshine with such little wiggle room. To solve this problem, another tool designer developed this circular copper tubing brush:
Same idea as the first tool in that the round, compact form works well in a constricted area. Just slap it onto the end of the pipe and twist until it's clean. The wire grid inside does the dirty work.
You can see how to use both of these tools in the video below, where a helpful DIYer demonstrates swapping the shut-off valve on a toilet line. (Same idea as doing it on your sink lines.) You don't have to watch the whole thing; the relevant demos start at 2:11.