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Random question - antifreeze

bgary

Advanced Beginner
Blogs Author
I see a lot of posts about using antifreeze to winterize (for example) fresh-water loop, by running antifreeze into the loop "until pink comes out the exhaust".

Are people doing that while the boat is in the water, or on the hard? I mean, with all the placards and warnings about putting things into the water, it seems to me that pumping antifreeze out the exhaust is A Bad Thing.

What am I missing?
 

u079721

Contributing Partner
I see a lot of posts about using antifreeze to winterize (for example) fresh-water loop, by running antifreeze into the loop "until pink comes out the exhaust".

Are people doing that while the boat is in the water, or on the hard? I mean, with all the placards and warnings about putting things into the water, it seems to me that pumping antifreeze out the exhaust is A Bad Thing.

What am I missing?

The antifreeze we are referring to is propylene glycol based, not ethylene glycol based like the stuff in your car. Propylene glycol is not toxic, and is even safe for fresh water systems - which is why it is sold to winterize water systems in RVs and boats. It's also the same stuff (mostly...) that is used to deice planes. (End of chemistry lesson.)
 

Walter Pearson

Member III
Some admit that a bit of propylene glycol in the lake when winterizing is not that harmful, but doing the same in spring commissioning might not be as acceptable. The reason given is that some heavy metals or other chemical byproducts can become part of the antifreeze over the winter. To be totally green, I would start the engine on the hard before launching and catch it all in a pail for disposal. DSCN2409.jpg
 

toddster

Curator of Broken Parts
Blogs Author
The truth is that traces of either ethylene or propylene glycol are readily biodegradable and will vanish before they can do any harm to anything. But you don't want to be dumping gallons of anything into the water. Especially in a marina, where everybody is doing it at the same time. If you can reclaim it, it's a good idea to do so.

BTW: If it says "biodegradable" or "non-toxic" on the label, it's because they paid me to test it.






Then I wasted that money on boats.



Except for the Coast Guard mil spec certifications for lubricants. Which are physically impossible. In that case, they've just shopped it around to different labs until they found someone who will lie for money.
 

Loren Beach

O34 - Portland, OR
Senior Moderator
Blogs Author
antifreeze and practicality

The truth is that traces of either ethylene or propylene glycol are readily biodegradable and will vanish before they can do any harm to anything. But you don't want to be dumping gallons of anything into the water. Especially in a marina, where everybody is doing it at the same time. If you can reclaim it, it's a good idea to do so.

BTW: If it says "biodegradable" or "non-toxic" on the label, it's because they paid me to test it.
Then I wasted that money on boats.

Except for the Coast Guard mil spec certifications for lubricants. Which are physically impossible. In that case, they've just shopped it around to different labs until they found someone who will lie for money.

My ancient degree is not in a related scientific field, but I do agree that these small quantities are not measurably "harmful" to the ecosystem.
We use and lose three quarts of pink antifreeze in a season to winterize our boat's little diesel, and that protects the raw water circuit from intake, thru strainer, thru HE, muffler, and out the exhaust. Boats here routinely live year-around in the water, but it's wise to drain or winterize all internal systems from december through February.... every decade or so we get a week of 20 degree weather combined with a 30 kt wind, and a few boats do sink when they later thaw...
:0

Sidebar: there is also some odd contradiction in the federal "law and rule" over the whole pollution issue. For instance, our club operates a small dredge with a 15+ gallon hydraulic tank required for constant recirculation. Many years ago we changed from petrol-based oil in that system to vegetable oil at the urging of the USCG, and our desire to mitigate any harm should we ever have a spill. (We have indeed had one incident where a split filter spilled quite a few gallons inside the dredge and we contained and cleaned it all up without losing any over the side.)

*Irony Alert: after the USCG thanked us for our oil replacement, they reminded us that the Law itself does not recognize any difference in these oil products and if we have a spill into the water, the same (!) legal requirements for notification and potential Huge fines would apply. :rolleyes:

So, I do "lose" that winterizing pink antifreeze because there's no practical way to catch it, but the quantity is very small.

Loren
 
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Navman

Member III
antifreeze

As already stated the correct antifreeze will not present any eco issues. I do prefer to winterize while in the water. It is easier to lower the antifreeze and bucket down into the boat rather than have to hump 6 gallons of antifreeze and a 5 gallon bucket up a 10' ladder and then into the boat. The yard then uses their work boat to put my boat into the slings for hauling. If the yard is not in a rush you can drive it into the haul out slip, winterize it and then they can lift it out.

Navman
E-38
SV- The Optimist II
 

toddster

Curator of Broken Parts
Blogs Author
In this case, the toxicity question is a canard. Consider that the theoretical oxygen demand of propylene glycol is about 1.7 mg/mg. A liter of sea water has about 9 mg of oxygen at saturation. If you dump a gallon of antifreeze into the water, the microbes that degrade it will suck all of the oxygen out of about 740,000 liters of water, over about ten days. (Not considering mixing and diffusion, but also, you don't need to suck all of the oxygen out to kill fish and invertebrates.) That's probably all of the water under your slip and the neighboring ones too. Since in the real world, there is mixing and diffusion, a boat basin can probably withstand a splash here and there. But not if everybody starts dumping gallons of it.

Yes, I've done it too. But I found that if I got the boat all winterized this week, there will be a perfect sailing day next week. Last year, I was out of the country when we had that unexpected polar vortex in November and air temperatures went down to 4°F. I hadn't done any winterizing at all. The boat came through just fine, (unlike the greenhouse :boohoo: )though I'm pretty sure that the river water temperatures were still fairly moderate. I do usually keep a small oil-filled heater on in the cabin.

Just saying, we haven't worked out the perfect solution yet.
 

Grizz

Grizz
Pink & Purple!

Oh, the things learned from reading this Forum. Awesome. I'm now either a) a habitual polluter or b) in compliance with all current laws. Not sure which, exactly!

Full disclosure: each October (or earlier, when the sale price is right), 1-gallon of pink and 1-gallon of purple is purchased, pink for the FW tank and head, purple for the engine; purple protects to a deeper freeze value IIRC.

Head and FW are winterized in harbor in advance. Boat is motored @ 5 nm down river (1 lock), a lovely if bittersweet trip through the heart of Chicago, and upon arrival at the boatyard, the engine is shut down, intake seacock closed, hose-clamps undone, hose-end pulled and stuffed into the purple jug and the engine restarted. Engine is turned off when purple is puking out the back, which coincides with about 1" remaining in the jug. Total time = 10 minutes.

This is the system repeated by the majority of those storing at this yard, unless they've got a pile of $ burning a hole in their pocket. These guys hire the yard to do their 'winterizing'. Same procedure, just more $.

Too late to alter procedures this year, boat's tucked away and awaiting Spring Splash.
 
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