Hi folks, A little while after this had happened we were talking to Sue and she said the shower sump pump exploded while Jim was working on it. I said, "Exploded???, little sump pumps don't explode". So I went over to talk to Jim and see for myself. First, Jim's index finger on his left hand was all swollen, the whole finger, like it had been wacked with a hammer. Fortunately, other than the swelling it seems ok, no burns and he could flex it without difficulty. Second, the pump is just as he described it. A small Rule 800gph pump, white plastic bottom with a red plastic top. 1/3 of the plastic top was broken off, the rest of the top was cracked and almost completely separated from the rest of the pump. The red plastic also had a crack running down the side of the pump body. Looking under the plastic top you can see the electrical connections for the two wires, they look ok, nothing special but the motor housing they are attached too is loose. There appears to be a little black soot mark on the inside of the red plastic top that is still attached but I'm not positive - didn't want to disturb the "evidence" for Rule to examine by breaking the rest off. There was no sign of overheating, no discolored plastic, no melting, etc. on the pump; just the blown apart plastic top. The pump was use the evening before when they took showers, nothing special, nothing changed. And no, there wasn't any special or new cleaning fluids used or any flammable liquid present - just the kind of stuff you would find in a shower sump. As you can imagine Jim and I talked about this most of the evening over dinner and didn't come up with any plausible cause. It appears like some kind of combustible gas collected and when he picked the pump up and turned it over it went BOOM!. Organic material when decaying can give off methane but that process should take a long, long time and since the shower was used regularly I don't see that as a plausible cause. His ears were ringing last night and fortunately are getting better but still ringing today. We are really puzzled. Any ideas??? Bob & Lynn Williamson On Legrace at Anchorage Marina, Baltimore MTOA #3839 From: palmettomoon [mailto:palmettomoon@mysc.com] Sent: Saturday, September 18, 2010 4:14 PM To: MTOA-Listserv@yahoogroups.com Subject: Bilge pump explodes (LONG) Palmetto Moon with Jim, Su, and lazy cat Alex are in Baltimore getting ready to start South. Yesterday, Friday Sept. 17th, I was filling H2O, checking fluids, general get ready for travel duties. Which included cleaning the shower sump and checking the pump impeller. This shower pump is done every 3-5 weeks as normal maintenance, same way always. The Rule 800 in the shower sump was not running, NO H2O in pan to make float switch rise. I grabbed the two ears on pump that hold into strainer frame and lifted pump body straight up. Then as always turned my hand over to check the impeller for hair and shower gunk. As I rotated my hand the pump EXPLODED, same loudness as a 12 gauge shotgun. Then a split second later another EXPLOSION not as loud, maybe like a 410 shotgun. The first happened in my hand, the second as it was falling into the bilge. Around the pump was a blackish liquid, not any color like anything you would see in a shower sump. ....

Several years ago I had an eerily similar episode occur. Heard the shower sump Rule pump running when it shouldn't have been. Took a peek to see the sump full and no discharge from the pump. Popped the pump out of its mounting bracket to check the strainer (pump still running, strainer plugged). Very shortly after that the pump exploded in my hand, though most of the discharge was from the bottom of the pump, with no injury. My conjecture was that the pump had been running essentially dry for quite some time cooled by the sump water, then overheated when I was too lazy to turn off when I lifted out of the water. I can envision steam maybe causing the explosion, and admit that I never considered hydrogen gas. As an old chemistry major, though longer ago that I'd like to admit, I can't think of a way for hydrogen to have been released, though I guess some sort of short could result in a degree of electrolysis, with breakdown of water to hydrogen and oxygen. I doubt that. The recent post reminds me of how happy I was to find that I had all my eyes and fingers. Dan Stone St. Pete, FL ----- Original Message ----- From: "Bob Williamson" <bob-w@swbell.net> To: "Trawler World List" <trawlers-and-trawlering@lists.samurai.com> Sent: Saturday, September 18, 2010 5:33 PM Subject: Re: T&T: Bilge pump explodes (LONG) > Hi folks, > > A little while after this had happened we were talking to Sue and she said > the shower sump pump exploded while Jim was working on it. I said, > "Exploded???, little sump pumps don't explode". So I went over to talk to > Jim and see for myself.