[Vwdiesel] More on overheating and plugged rads

[Shalyn Shourds]

>If there are any organic chemists in the list, please comment. 
>I know you can drink PG safely, and it is used in many foods, like Ice cream.
>I wonder if EG (ethylene glycol) is somewhat similar stuff? (but poison)
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I was just remembering how long it's been since organic, but yup, 
they're very simiar.  Propylene glycol just one more carbon in the mix.  
Ethylene Glycol itself isn't the poison problem.  What happens is we (or 
the cat or whatever) drink it and the body metabolizes it into a 
poison.  Takes the long way around, but it's the same trip to the morgue 
(at sufficient concentrations, etc.).   I guess propylene glycol goes 
down a different road.  (It's late and I can't find the pathways for it.) 

OHCH2-CH2OH   Ethylene glycol     CH3-CHOH-CH2OH  Propylene glycol

>I suspect some kind of bacteria enjoy munching on the stuff when it is at
>the right temperature, turning it to jelly.
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I can't really say what happens to the stuff in the wild.  I found a 
pathway for ethylene glycol metabolism, but it's a small molecule and 
gets smaller fast.  Didn't look like anything that would polymerize 
(I'll leave it to a real chemist if we have one in stock--I'm a 
microbiologist who's rapidly forgetting all his chemistry.  Anybody need 
an environmental microbiologist for a job with some thinking involved?) 

I do know that the lettuce in the back of America's refrigerators is 
turning to a nice chunky slime.  (The stuff in the back of Canada's 
refrigerators is frozen.)  That's bacterial cells and extracellular 
polydextrans, etc. 

Other complicating factor is that there is a whole lot of other stuff in 
the mixture.  Science generally takes place in clean glassware and 
double-distilled water.   Hard to tell what's going on after a few years 
of running around in a high-temerpature engine with sundry additives, 
dissolved metals, exhaust gasses, oils, fuels, and that water you really 
probably shouldn't have put in the radiator but the crick looked pretty 
clear. 

Long scientific version of, "Heck if I know."

-Shalyn