What anti-freeze to use for engine winterization?

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BillWilliams

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I know this is probably a silly question but what anti-freeze do you good folks use?

For the last 20 years I've been using conventional automotive antifreeze and I figure that has to be a more economical choice that works as well.

Thanks
 
I always use propylene glycol - this stuff. https://www.westmarine.com/buy/west...-system-antifreeze-gallon--499848?recordNum=2

Some people go cheaper, and put the potable water tank antifreeze into their motors - this stuff - but doesn’t have the same corrosion resistance, I believe. Probably works though. https://www.westmarine.com/buy/seaf...cohol-antifreeze-gallon--14823330?recordNum=1

You can go stronger, for up to -100 protection - but not sure if that is overkill or not. Depends on your climate. https://www.westmarine.com/buy/west...-system-antifreeze-gallon--363798?recordNum=3

I’ve never used automotive antifreeze - because it’s toxic to animals, and also tastes very good - dangerous combination, Too many dogs in my neighborhood to just flush that stuff out of the motor.
 
whatever you are thinking of using, put a jug of it in the freezer at the lowest temp you might see. For us that's about zero. I found that both the -50 and -60 got solid but did not break the plastic jug, the -100 stays liquid. I would not want something that gets solid inside of a cast iron engine. So the -50 and -60 for me is out, even though they are widely used.
There is yet another cheaper alternative to the -100, if you can find Sierra brand PG antifreeze, if you mix it up 50/50 it gives freeze protection down to -26*F, and has enough anti corrosion additives to be used as an engine coolant but is still a PG non tox antifreeze. This is what I use now...at zero degrees it stays liquid just like the more expensive -100 I used to use. It's roughly half the cost of the -100, I think approx $7.50 per gallon (a gallon of Sierra costs about $14-$15 but when you mix it with water you get 2 gallons to use), the -100 was about $14 for one gallon IIRC. More than the cheap stuff (-50 or -60) but much better. Keep in mind that they get solid a few degrees above zero, the -50 or -60 is not freeze temp its burst temp, what temp a copper pipe will burst.
 
If you're using regular ethylene glycol to winterize the raw water sections of your engines, you shouldn't be. Way too toxic, illegal to dump in waterways and dangerous to let it run down your driveway. Could kill some neighborhood dogs that are attracted to it by the sweet smell.
 
I use the pink stuff as per my mechanic here in NY. We do engines, generator, AC, head, waste & fresh water systems with it.
 
If you use normal toxic automobile coolant then you should try and catch it and dispose of properly. Many people use the pink RV antifreeze for winterizing. I typically drain the block then fill with the RV pink antifreeze.
 
definitely do not use the toxic ethylene glycol antifreeze because you will inevitably spill it when draining it and/or when you start up in the spring it will get all over wherever the boat has been stored. For sure do NOT start it up in the water!
If you get close to zero or below temps then what I said above I feel holds true, use the -100 which has a more than adequate freeze protection (the -100 is burst protection, the actual freeze protection is approx -55*F), or mix up the Sierra PG antifreeze 50/50 with water that gives you -26*F freeze protection. That's what I do now....
 
Thank you everyone. Yeah, I have been using the toxic stuff (I know, that's bad). We live out in the country and so I'm not concerned about neighbors animals and I have always started it on the ear muffs to flush the engine. I'll be switching over to the pink stuff this time.
 
Correct me if I'M wrong, but aren't there several types of propylene glycol antifreeze? Some are exclusively for potable water systems and some with corrosion inhibitors are for winterizing marine engines?
 
The pink RV stuff at Walmart has some corrosion inhibitors as there is likely to be some non plastic parts in the RV water system. Brass, bronze, copper, probably not aluminum or cast iron. Places like West Marine sell anti freeze specifically for boat engines and it goes to a lower freezing point. More $$ than the pink RV stuff, and in theory better and less corrosion. But an awful lot of boaters use the pink RV stuff.
 
The main difference in the "pink" antifreeze is some are ethanol glycol and others are propylene glycol based. The ethanol glycol is usually cheaper and does not have the anti-corrosion properties propylene glycol has (it's alcohol based). I always pay a little extra for the propylene glycol, I am more interested in corrosion protection than freezing. Also, these antifeezes are not designed to stay liquid down to their rated temperature - they will freeze solid sometimes. The difference is they do not expand like water when they freeze.
 
I did panic about 15 years ago, was doing some engine work over the winter, pulled a head off, and was horrified to see the motor filled with frozen “pink stuff”. But as you said, it wasn’t solid ice, like you get with water, was more like shaved ice, could stick my finger right through it.
 
That is correct, some are for water supplies, and don't use corrosion inhibitors, you should use the type of PG antifreeze that's meant for engine systems, with corrosion inhibitors. The West Marine -100 stuff and the Sierra PG stuff both have it. Personally the only AF I will put in an engine is the kind that stays liquid well below zero. No -50 or -60 stuff for me.
 
That is correct, some are for water supplies, and don't use corrosion inhibitors, you should use the type of PG antifreeze that's meant for engine systems, with corrosion inhibitors. The West Marine -100 stuff and the Sierra PG stuff both have it. Personally the only AF I will put in an engine is the kind that stays liquid well below zero. No -50 or -60 stuff for me.
 
That is correct, some are for water supplies, and don't use corrosion inhibitors, you should use the type of PG antifreeze that's meant for engine systems, with corrosion inhibitors. The West Marine -100 stuff and the Sierra PG stuff both have it. Personally the only AF I will put in an engine is the kind that stays liquid well below zero. No -50 or -60 stuff for me.
 
BillK,you have it backwards. Ethylene glycol is the one with corrosion inhibitors (plain old car antifreeze), while propylene glycol is the pink stuff for potable water systems etc. Some propylene glycol can be used for engine winterization because they add corrosion inhibitors. Sierra is propylene glycol made for car radiators.
 
I am talking about ethanol glycol, not ethylene glycol -- there are two formulas of the pink stuff. The cheapest pink at Walmart is ethanol glycol, the more expensive pink at say West Marine is propylene glycol.
 
BillK, ethylene glycol is ethanol glycol. Ethanol is ethanol=a type of alcohol. At least it was when I took organic chemistry and pharmacology. Pink (propylene) is pink for a reason, to differentiate it from ethylene glycol(usually green for identification).
 
Then maybe I have my terminology wrong - I always thought there was an ethanol based pink antifreeze and a propylene glycol based - the ethanol (alcohol) one being cheaper and not having the anti corrosion properties. Figured that was why the Walmart brand is $2.50/gal and the West Marine stuff is $5/gal.
 
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