Science fair project in bilge

[Banooma]

My boat is sitting on the hard, and we're pulling out of a relatively mild winter. Back in October - prior to haulout, I'd poured a few inches of the nontoxic pink antifreeze everyplace water might be inclined to sit, including the bilge. As I recall, that pink solution was exactly as I'd left it the last time I checked - maybe 2 months ago. As of this weekend, it appeared to be a glowing green color much like toxic engine antifreeze. Adding just a little pink antifreeze to this solution seemed to dispel the green glow, but leaves me no less curious. Every other tank or open area that I addressed in the fall remained pink. Might there be a tendency for a mold of this color to evolve? The green color did not appear to have dripped from the engine. Any ideas where else might it have come from?

 

[Ross]

Dip out a sample and study it in a glass container. Stretch a coffee filter over the top and secure it and let it sit for a few days and look again. Do you have a good microscope? You could have all manner of things growing in there.

 

[Don S/V ILLusion]

Pink antifreeze is not a good media in which stuff grows normally. It contains no organic material on which bacteria can feed. It's more likely the color is either a remnant of what was in the bilge or an ethylene glycol leak.

 

[RichH]

Sorry Don.
The pink stuff is propylene glycol and many bio-forms can thrive in it especially when diluted with water - mostly bacteria. There are very few things on this planet in which bacteria cant thrive.

 

[Don S/V ILLusion]

Oooops!
As various glycols are used as disinfectants, I just assumed it makes for a poor bacteria growth environment but you are quite correct Rich (as usual).

 

[Maine Sail]

My guess

My first instinct would be an ethylene glycol leak. In the winter, when it's cold, engine components contract and often times a marginally pressure tight hose or other part of the cooling system becomes not pressure tight and begins to leak. As the temps rise the leak again stops. I've witnessed this before with boats that sit in cold climates.

Take a white rag and wipe around each and every fitting containing engine antifreeze, including the water heater connections, and you just may find remains of "green stuff" even though it may not be leaking at this temp currently..

While it is quite possible to grow a science experiment in the bilge it is rarer in colder temps than in warmer ones..

 

[Ross]

Sorry Don.
The pink stuff is propylene glycol and many bio-forms can thrive in it especially when diluted with water - mostly bacteria. There are very few things on this planet in which bacteria cant thrive.

I read somewhere that they found a bacterium the consumes pentachlorophenol. And that is about the nastiest stuff on the planet.

 

[Stu Jackson]

While you're looking for the green stuff leak

check your hot water heater connections, too, and the level of antifreeze in your engine. If it's low(er), that'll be a giveaway.

 

[Manny]

I've had all sorts of nasty things growing in my bilge after letting the pink antifreeze sit in there during winter. I get rain water in there and when it mixes together it gets pretty gross. Not toxic green but close...

Manny

 

[pvanv]

I don't use antifreeze any more. I drain everything, and I drilled out the lowest point of the keel sump (and installed a garboard drain -- threaded from inside so I don't need to dive to access it). I leave the bilge dry, with a rag as a wick in the drain. Cheaper, easier, no chemistry needed, and bone dry bilge in the spring.