Engine Antifreeze for Winter Lay-Up

[enovillo]

Hi all,

It's my first time winterizing a diesel, and I'm not too sure about what antifreeze to use.

Calder's book recommends propylene glycol as opposed to ethylene glycol, with the former being less toxic and relatively environmentally friendly.

Also, I've read posts in this forum that talk about "RV antifreeze" being used for engine winterizing (this type of antifreeze is always propylene glycol because it's meant for RV plumbing systems). But all the labels on the RV antifreeze jugs I found say it shouldn't be used for internal combustion engines.

I wasn't able to find engine antifreeze that's made of propylene glycol.

Is RV antifreeze ok for winter lay up, even if the label says it shouldn't be used for that?

I don't think the engine make and model matter much for antifreeze selection, but this is what I have: Yanmar 2GM, built in 1982.

One last thing: I thought that because I'll use propylene glycol I'd be able to just start the engine in the spring and let the exhaust system dump the antifreeze in the lake. Well, that's not true. It needs to be properly disposed of, just like any other antifreeze. Which begs the question: why use propylene glycol instead of ethylene glycol then?

[S&S]

It's not recommended for the "fresh water" side of the cooling loop. We get the -70F propylene glycol "potable" antifreeze and suck it through the raw water side of the engine until it comes out the back (and then some). Works great. Rigged a 5 gal jug with a hose and valve- I think West sells them. Remove the raw water hose from the seacock, insert the hose from the tank into the engine inlet hose and start the engine- done in under 5 minutes.

This is for the raw water side only.

Who said that you can't dump propylene glycol (at least a couple of gallons) into the lake? It's not toxic ( used in various foodstuffs-ick)

Ethylene glycol based antifreeze is for the closed loop in the engine. It's toxic and should be disposed of properly.

[enovillo]

Thanks S&S! Now that you mention it, I remember reading on the labels something about not using plumbing antifreeze for "closed loop" something-something.

AFAIK, the 2GM is raw water cooled (please correct me if I'm wrong, I'm taking baby steps into this mechanical maintenance stuff). That means there's no "fresh water" side of the cooling loop, right?

[S&S]

Not familiar with that engine, but it's easy to check against the manual( they won't mention a heat exchanger). If it's raw water cooled, then you would do the same thing. Just run it long enough so that the glycol displaces all the water in the block. The inlet seacock stays closed until spring (replace the hose on the seacock barb to keep the glycol in the engine). The -100F (purple) antifreeze has less water in it so would work better for a raw water cooled engine.

See if yours is an "f" series. That's the designation. also Fresh water cooling means two pumps (visible on the engine front)

http://en.wikipedia.org/wiki/Yanmar_2GM20

[barnakiel]

Glyco half-and-half distilled water, or a premix made to allow for your winter temps. Many gas stations sell them as a pre-mix.

Fill from the raw water inlet side and get the engine goin' till the coloured water gets out from the exhaust. If in any doubt about the fresh water part (if you have a fresh water cooled engine) also replace the liquid in the fresh water system with the pre-mix (but normally it is already exactly wht you have there).

The fresh water side mix is replaced annually.

b.

[thinwater]

to a fish. Look up MSDS information on-line regarding marine toxicity. You will find there is no difference. Just as chocolate is bad for dogs, toxicity varies between animals. Humans take zinc pills, while zinc is deadly to fish.

If disposing of the AF in the sewer or with your black water in a pump-out station there is no difference. The waste treatment plant will handle both with the same effort and same result.

Propylene glycol is for potable water systems - VERY IMPORTANT! In all other applications, it makes no difference. Both can easily be recycled. So I would use which ever formulation of engine AF makes you happy.

Disclosure: I work for one of the larger AF reprocessors in the country. We manage both EG and PG. We also run waste treatment plants disposing of both, when not recyclable and the left overs.

[thinwater]

They hide behind burst point temperature ratings, which have no industry standard definition (call an AF testing lab and ask for the official method). They should put PG % on the lable. It would be honest of them, agreed?

The MSDS (on-line) will give the correct PG content in %.

Regular AF manufacturers (automotive) cannot get away with this sham because they have legal disclosure requirements and standard tests to meet.

Weird.