T&T: Winterizing a boat

[Wesley & Patty Eldred]

Larry's post is, as usual, thoughtfull and informative.  My only point of 
disagreement has to do with the use of automotive antifreeze for the engine 
cooling raw water circuit and the toilet.  The raw water discharge from the 
cooling circuit is via the engine exhaust and the cutless bearing for many 
of our boats and neither lends itself to effective collection of the 
discharged coolant.  Ethylene glycol is neither safe nor legal to discharge 
and, to the best of my knowledge, has no advantage over the propylene glycol 
used in potable water systems.  I also would not use ethylene glycol in my 
holding tank and doubt if any waste treatment plant would welcome it. 
Again, propylene glycol does just fine.

Wesley
wpeldred at comcast.net


----- Original Message ----- 
From: <LRZeitlin at aol.com>
To: <trawlers-and-trawlering at lists.samurai.com>
Sent: Monday, October 01, 2007 10:05 AM
Subject: Re: T&T: Winterizing a boat


> 3. Flush the boat's raw cooling water system with a 40% mixture of 
> automotive
> antifreeze. I put the antifreeze mixture in a 5 gallon bucket (two gallons 
> of
> antifreeze to three gallons of water) then, attaching a length of garden 
> hose
> to the raw water pump intake, I run the engine for a minute or so to suck 
> it
> into manifold, heat exchanger and waterlift muffler. I've installed a T
> fitting in the intake line after the intake stopcock to make the job 
> easier.
> If the
> boat is on stands, collect the discharged antifreeze/water mixture in a 
> bucket
> as it emerges from the exhaust or the raw water discharge thru hull. Use 
> it
> in the next step.
>
> 4. Flush a gallon of so of the antifreeze mixture through each head. The
> mixture will go into the holding tank where it won't do any harm and may
> prevent
> any residual  water from freezing up.