Is antifreeze necessary?

A

airrc81

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Joined
Nov 11, 2005
RO Number
19533
Messages
11
I have a 2007 Bayliner that I am getting ready to winterize for the first time. I have just a couple questions before I jump in.

The boat has a new Mercruiser 3.0 with the easy draining water hoses. If I drain the water from the system do I need to refill it with antifreeze?

If so, is it better to leave it filled with AF or drain it back out after it has circulated?

I also have a 9.9 hp kicker, is it necessary to run antifreeze through it as well?
 
You don't say where you're located. If your winter temps will hit the freezing/sub-freezing levels, you have two choices: 1) Drain block completely...no harm here except leaving an empty block invites surface corrosion 2) Run anti-freeze into it. I've heard two schools of thought here...a) use RV pink propelyne glycol AF, or, b) go with a 50/50 mix of tried and true ethelyne glycol.

At recommissioning time...UNDER NO CIRCUMSTANCES DRAIN THE AF INTO LAKES, RIVERS, OCEANS, ETC.

DO NOT LEAVE RAW WATER IN THE BLOCK!

O/B's do not have to be "winterized". Perhaps remove it and store it in the garage.
 
When you drain your engine block, you often have pockets of water left behind that can and will freeze.

Replace that water with rust inhibiting AF and you will be fine.

As Mike mentioned, you don't say where you are or if the boat is left in the water or not. Makes a difference once we know the answer to both those questions.
 
Boat will be out of the water for the winter. I'm sure we'll be experiencing some freezing temps over that time. I've drained the block etc., but it sounds like I need to fill it with AF now, more for corrosion prevention than anything else.
 
Propylene glycol AF (not pink) like Sierra or Prestone's Low-Tox gives me the -25°F protection I'm comfortable with at a 50/50 mix & is much more environmentally friendly. It's not considered non-toxic because of the additives....rust inhibitors & water pump lubricant.
 
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