Drain plugs: Leave them in during the winter or take them out?

[egclassic]

Re: Drain plugs: Leave them in during the winter or take them out?

"The cooling system is the main area of concern. All inboard and sterndrive engines have petcocks that are either turned or removed in order to drain water from the block, exhaust manifolds, and hoses. These petcocks can become clogged with debris. You can poke a wire into the drains to remove the debris and allow water to drain. Temporarily remove the water hoses that feed the block and manifolds, and pour antifreeze (red RV is recommended) into them until it runs out of the petcocks.

The drain system on your engine is NOT intended to replace full winterization. It is for extending your boating season by allowing the cooling system to be drained after use if there is a risk of light freezing weather and you will be boating the next day. For full extended winter storage, after completely draining the cooling system, Mercury MerCruiser recommends the use of propylene glycol antifreeze (with a rust inhibitor for marine engines) in the sea water section of the cooling system."
I put mine back in and follow the manufacturers recommendations.

 

[redjmp]

Re: Drain plugs: Leave them in during the winter or take them out?

If you replace the plugs, you cut off the supply of oxygen and therefore limit the amount of rust that can form inside...once all the oxygen is used, rusting should slow right down...

 

[Haffiman]

Re: Drain plugs: Leave them in during the winter or take them out?

I always filled the cooling systems with anti-freeze on my customers boats, and removed all hull and compartment drain plugs.
Put the plugs in a Zip-bag, sprayed in some anti-fogging oil and tied the bag to the steering wheel,
Had a tape on the keys: Drain plugs removed!!
Never sank a boat, never had a cracked block or manifold.
That with temps down to -25C (-14F).

 

[paultjohnson]

Re: Drain plugs: Leave them in during the winter or take them out?

If you replace the plugs, you cut off the supply of oxygen and therefore limit the amount of rust that can form inside...once all the oxygen is used, rusting should slow right down...

HMMMMMMMMMMMM.... Thats an interesting concept to me.... I was thinkn' leaving the plugs out and hoses disconnected would allow the insides to dry out, And THAT would slow the rust down.
Your theory does remind me of of situation my neighbor got himself into. His boat at his cabin swamped in a storm, outboard was submerged for a week. Mechanic said once you pulled it out of the water, you gotta get to the repairs asap as the real water damage starts AFTER it hits air... huh........


So now I gotta wonder which method would inhibit rust rust better

1. plugs replaced, engine buttoned up, residuel moisture trapped, but less oxygen.

2. plugs left out, hoses disconnected, internals dry out better, but exposed to oxygen.

Anyone???

 

[Brewman61]

Re: Drain plugs: Leave them in during the winter or take them out?

The answer seems obvious to me. First, blow warm dry air thru the entire cooling system for many days to ensure there is no moisture at all. Then flush the entire cooling system with nitrogen to remove all traces of oxygen.
Without moisture and oxygen, rust is impossible. Finish up by sealing the drain plugs with special green colored caps, to let everyone know that the system is filled with nitrogen.

 

[Lou C]

Re: Drain plugs: Leave them in during the winter or take them out?

This is why you use Antifreeze, you keep the Oxygen out that way, and Merc Volvo and OMC all recommended this in their manuals...rust of cast iron is iron oxide, there's plenty of oxygen in air...but...you should only drain and backfill on an raw water cooled engine...don't use the suck it up the drive method....not safe....

 

[Beefer]

Re: Drain plugs: Leave them in during the winter or take them out?

Can I change my vote? I live in Florida, and the word 'winter' isn't in my vocabulary - I thought the OP was referring to the garboard drain... :redface:

 

[Brewman61]

Re: Drain plugs: Leave them in during the winter or take them out?

Well of course you can change your vote. You live in Florida, the land of the dangling chads, so your vote is widely open to interpretation, anyway!

 

[jetmart]

Re: Drain plugs: Leave them in during the winter or take them out?

Well of course you can change your vote. You live in Florida, the land of the dangling chads, so your vote is widely open to interpretation, anyway!

That's the best reply I have read on this forum in a very long time!

 

[jason32038]

Re: Drain plugs: Leave them in during the winter or take them out?

If you're talking about the boat drain plug...I leave that out.

 

[Don S]

Re: Drain plugs: Leave them in during the winter or take them out?

After 4 months, this thread is closed.