Winterizing

[thaeni]

I have a 3GM30F and was wondering if I could use the antifreeze used for
water systems in my engine. The only thing I need to protect is the water pump
and the heat exchanger.

 

[Rob2435]

I have the same engine and use the pink or purple stuff. You have to make sure that the engine, spits out the antifreeze to make sure that it has fully made it thru the engine. I close the seacock on the input hose and use the strainer to feed the engine until it starts spitting out the product I am using. Has worked for the last 10 years...

 

[Meriachee]

Exactly. The big trick is to get it all the way through, you'll be quite surprised at just how much that little water pump gulps.

 

[thinwater]

Actually, the real answer is that PG (water system antifreeze) is VERY hard on neoprene water pump impellers, and vehicle antifreeze (EG) is generally a much better choice.

• Toxicity. Human/mammal toxicity should not matter since there is no plausible exposure path.
• Marine toxicity is the same for bot types. Don,t believe me, look at the MSDS sheets and compare. There is a lot of false information out there, but the MSDS sheets are true. The EPA did a big study of this for airports.
• Biodegradability. EG is actually a little easier, but both are very degradable. Sewage treatment is not a problem, but recycling is better. They can both be recycled in the same plant, mixed (I've designed the recycling plants).
• Even the least expensive vehicle AF offers better corrosion protection than PG. Neither can be prevented from going acid (fermenting) unless they are at least 30% glycol.
• Less EG is required, since it is a better freeze point depressant.

The same is true of winterizing sanitation systems; pink AF will ruin the joker valve in many heads (NA Rairitan, since they use nitrile). No one is going to drink from the black water side.

Really, PG (pink) AF is only required for the potable system.

I did a bunch of testing on this for a group of magazine articles.

 

[Don S/V ILLusion]

Another caution when using pink antifreeze - its efficacy is nullified if mixed with ANY water such as what happens when run through an engine heat exchanger. Simply displacing water with this type antifreeze as will happen while running the engine water pump runs the risk of mixing.

That's a potentially expensive engine replacement for little if any environmental benefit. Clearly, some people have 'gotten away with it' which begs the Clint Eastwood question " do you feel lucky.."

 

[Benny17441]

Why? Automotive antifreeze does and has been doing a good job for years; what do you expect to gain in cost/performance?

 

[quadrille38]

The pink rv stuff typically doesn't have a cold rating low enough to make me comfortable using it in the engine.

Automotive anti freeze is not legal to discharge into the water as it is toxic. There is no way to flush the heat exchanger and cooling system without discharging some of the antifreeze

They make a biodegradable type with colder temp protection than the plumbing system stuff. That's what I use in the engine.

 

[Meriachee]

We've used the rv stuff for years and the worse ever seen is the stuff turning to something like a slushy at -40.
And the C and F scales converge at -40.

 

[thinwater]

The pink rv stuff typically doesn't have a cold rating low enough to make me comfortable using it in the engine.

Automotive anti freeze is not legal to discharge into the water as it is toxic. There is no way to flush the heat exchanger and cooling system without discharging some of the antifreeze

They make a biodegradable type with colder temp protection than the plumbing system stuff. That's what I use in the engine.

Don't just say it, prove it. Do you have any evidence that PG is less toxic to marine life and more biodegradeable? Either scholarly work or MSDS infor would help. More likely, you have been given bad information by the folks selling PG.

My information is below. There are many information sites, including state EPA sites, that have simply copied false information from other sites, copied from folks that have an ax to grind. The simple truth is that for the fish there is no difference. Mammals are not fish, and toxicity chemistry is very different.

2 MSDSs
http://www.sciencelab.com/msds.php?msdsId=9927239
http://www.sciencelab.com/msds.php?msdsId=9927167

And an EPA study
http://water.epa.gov/scitech/wastetech/guide/airport/upload/2005_10_07_guide_airport_airport.pdf

(section 9.1)
"Several toxicity studies have been performed using pure ethylene glycol and propylene glycol. The results of these studies generally show that both ethylene glycol and propylene glycol are similar in aquatic toxicity and are fairly nontoxic to the aquatic environment."

 

[thinwater]

We've used the rv stuff for years and the worse ever seen is the stuff turning to something like a slushy at -40.
And the C and F scales converge at -40.

^^ Absolutely true.

I think what the posters are warning people about is if they do not get all of the water out first, or if they skimp, thinking they can water it down in a warmer climate, the protection falls off FAST. I have seen broken pipes in systems with not enough PG.

The other problem is that weak PG can ferment and turn very acidic. I've seen pH as low as vinegar.

Used full strength, no problems.

 

[Meriachee]

^^ Absolutely true.

Thank yew kind sir. :neutral:

Myself and my band of com-padres up here in the frozen north will very likely keep on doing what we've always done, using the potable stuff, making sure the exhaust is spitting really pink, or 4 gallons, and changing the impeller in the spring, not because of any (not to insult anybody) urban legends, but because it's the right thing to do. I can buy an awful lot of this stuff, and a lot of impellers for the cost of a heat exchanger. The cost benefit suggests something like 36 years. It's never killed the grass at the acreage, unlike what happened to the lawn one time when a jug of Prestone fell over.

Like Stu says, your boat, your choice.

 

[Meriachee]

...and not to hijack the thread, but I'd like to say that it was a particularly sad time last weekend when the boats came out, the feeling hasn't left, a solid week later, and this discussion of things -40 isn't helping. :cry: I'm excusing myself from this thread.
Cheers
Gary

 

[Don Crowther]

Just to be sure of which side of the cooling system is being discussed here. On the fresh water side ( the side that comes from the lake) I use RV anti-freeze for the winter. After I pull for the year I change the oil and filter then start it and run RV though until I see pink.

On the engine side (the side that remains in the engine) I use regular anti-freeze pre-mix that's good for -40.

 

[Claude L.-Auger]

Just to be sure of which side of the cooling system is being discussed here. On the fresh water side ( the side that comes from the lake) I use RV anti-freeze for the winter. After I pull for the year I change the oil and filter then start it and run RV though until I see pink.

On the engine side (the side that remains in the engine) I use regular anti-freeze pre-mix that's good for -40.

Don, there is a lot of water in the engine heat exchanger, water lift and exhaust line. Do yourself a favor and test the antifreeze you'll see coming out of the exhaust when you run it through. Chances are it'll show up at somewhere around - 10 (C), which is clearly not enough in your neck of the woods (or mine LOL). Just run some more through until what you get test at what you want. Because I winter in Florida I do not go to my boat from late October to mid-April. Safety of the mind makes me run antifreeze through until it reads -40 at the exhaust. Then I know the engine is thoroughly protected. BTW I use the green stuff (ethylene glycol) in the engine and the pink stuff in the boat fresh water system. The hot water tank gets drained and is by-passed as I do not want the pink stuff in there. Less than a month to go here before haul-out. Good sailing left yet !

 

[thinwater]

The cost benefit suggests something like 36 years. It's never killed the grass at the acreage, unlike what happened to the lawn one time when a jug of Prestone fell over.

Like Stu says, your boat, your choice.

Your not understanding.

a. It was not the EG that killed the grass, it was probably either that it was "old" Prestone, which had a high pH additive pack, or that it was concentrate (pink is only 30% PG) and PG will also kill the grass at full strength, as will salt or sugar. It is an osmotic pressure issue, not toxicity. The newer formulations are much less alkaline.
b. There is no real cost difference, either way. Just which is better.
c. Automotive AF is going to be better for the HE than PG, but they are sufficient corrosion resistant that it doesn't matter.
d. As for human toxicity, remember not to drink the hot water; there is always some chance of a leak from the engine coolant into the hot water heater.

Puzzle for a few minutes why NO automobile uses PG for factory fill. The answer (I am on the ASTM committee) is that it does not work as well.

 

[Don Crowther]

Claude;

Green in the engine and 5 gals of pink though the heat exchanger/exhaust. No anti-freeze in water system as I blow all lines out with compressed air.
Only 2 weeks until I haul out. Maybe 3 if i'm lucky.

 

[Warren Milberg]

This is one of the best and informative threads I've ever seen here....

 

[Jackdaw]

The other key thing to remember that the real risk to a winterized engine is not the liquid in the cooling system becoming solid, but it EXPANDING.

Water (H20) is very unique in that it expands when changing from its liquid to solid state. Nothing else does that. That's why it cracks pipes when it freezes.

Like most substances, propylene glycol contracts when it freezes, and a 50:50 PG/water mix stays so close to the same volume after it freezes or turns to slush that is is unlikely to damage parts unless the motor is started when it is frozen.

 

[Capt jgw]

When I worked at West Marine and could get the stuff cheap, I used their purple non toxic AF for the engine. Now I can get auto AF cheaper, I use whatever brand is cheapest. I run it through on the hard and put a bucket under the exhaust to catch it and test to make sure it's not diluted too much. To be legal, you should run some plain water through in the spring to flush the AF out so it doesn't go in the water.

 

[thinwater]

The other key thing to remember that the real risk to a winterized engine is not the liquid in the cooling system becoming solid, but it EXPANDING.

Water (H20) is very unique in that it expands when changing from its liquid to solid state. Nothing else does that. That's why it cracks pipes when it freezes.

Like most substances, propylene glycol contracts when it freezes, and a 50:50 PG/water mix stays so close to the same volume after it freezes or turns to slush that is is unlikely to damage parts unless the motor is started when it is frozen.

^^ Very true. In fact, the industry-standard way to test burst point is to fill a glass vial completely full (no air), invert, and place in a freezer. The glass will not burst until the last bit freezes. So long as it is a slushy, the water contracts while the ice expands.

The one exception to this (I've seen this MANY times) is if there are freeze/thaw cycles, and complex non-circulated piping. The ice floats (water), lowering the concentration in the upper parts of the system, and bursting is possible only a little below freezing, since the mixture has stratified. Plastic piping is also more vulnerable (very brittle in the cold) For this reason I protect to the freeze point. This costs nothing more in my climate, since I have to use 30% glycol to prevent fermentation anyway.

And yes, it ferments. Just smell some of the jugs near the recycle drop off next spring. Those that are diluted generally STINK and are acidic.