Antifreeze Types

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

PCoch

Veteran Member
Joined
Sep 18, 2013
Messages
63
Sorry if this is a repeat - I did a search in the forum but was inconclusive.

Is marine antifreeze recommended over products in auto parts stores? Just like everything else marine, antifreeze is 50% more than for autos.
 
What is important is what engine you have...the rEST is just ma king sure your antifreeze merts the one specified for the engine, no matter the origin..
 
What is important is what engine you have...the rEST is just ma king sure your antifreeze merts the one specified for the engine, no matter the origin..

Thanks. So there aren't properties of marine A/F that auto A/F doesn't have?
 
Can't say that for sure...but if your engine calls for an antifreeze meeting specification XXX, it doesn't matter whether you use some marine labeled coolant that brags it has kryptonite in it.

Usually people use whatever coolant their engine is...Cat for Cats, Deere for Deere, Volvo for Volvos, etc..etc...

Now I have an antique Ford Lehman, probably manufactured before they invented antifreeze, so a Lehman specialist said any old, plain green ethylene glycol will work just fine.
 
Last edited:
Can't say that for sure...but if your engine calls for an antifreeze meeting specification XXX, it doesn't matter whether you use some marine labeled coolant that brags it has kryptonite in it.

Usually people use whatever coolant their eine is...Cat for Cats, Deere for Deere, Volvo for Volvos, etc..etc...

Now I have an antique Ford Lehman, probably manufactured before they invented antifreeze, so a Lehman specialist said any old, plain green ethylene glycol will work just fine.

HaHa - Gotcha! Thanks again.
 
Go with the formulation specs the engine manufacturer recommends, it is usually the same whether the particular engine model is in marine use or on land.
 
Greetings,
Mr. PC. Yup, what Mr. ps. said. I have twin Lehmans and use a 50/50 premix DIESEL antifreeze in them. I think it's important to use diesel specific AF because I think there are additives/modifiers not contained in the auto AF but I stand to be corrected...
 
Last edited:
Cavitation is the bigger issue. Some engines have bubbles form on the water side of the cylinder causing pitting. Without proper antifreeze additives the cavitation will ruin an engine. My Ford pu has this issue. There are testers. It's best to just use the antifreeze recommended. Additives and test strips/kits are online and probably at truck stops.
 
Not many of us need a 50/50 mix.
Unless it gets really really cold (and where most of us live it doesn't) 60/40 is better. Sixty percent water. Distilled. No additives and orange type where the coolant comes in contact w aluminum. Mine dosn't so I use green .. 60/40.
 
American diesel said last year just use regular old Preston green from Walmart, etc. The design is old enough it doesn't care.

Yes cavitation is an issue, a BIG issue with some diesels, not all. Certainly not Lehman based on the recommendation of the cheapest antifreeze possible.

Most boats can alter from the 50/50 mix but why? It's usually not critical...but why make a big deal over nearly nothing.

The best advice is use the recommended antifreeze by the engine manufacturer....don't just go by color, go by specification.

Seems like with everything else discussed here, lots of opinions, good info, bad info, no info...so just follow due diligence with engine specific research...
 
Antifreeze is confusing.

I've had to do a lot of research on antifreeze on our heavy machinery at workto work out what all the choices were, so I'll try to summarize the info.

There are two type of bases for antifreeze.

Normal antifreeze is ethylene glycol based which is poisonous to marine life (and humans). Marine A/F is propylene glycol based. It still does the same job, but is non toxic (and more expensive). If you use the non-marine type take extra care to suck up any spills from the bilge and dispose of it properly.

Their are 3 types of additive packages for either of the above bases.

IAT (Inorganic Acid Technology)
The most commonly antifreeze in North America uses silicates and phosphates as corrosion inhibitors. The diesel version also uses nitrate based additives to prevent cavitation on wet liners. The nitrates need to be kept at 800 ppm to protect the liners. The nitrates slowly deplete so it needs to be tested periodically and additives added, or changed out completely. IAT antifreeze is usually green, but not always.

Their are two other types of antifreeze which are very common outside of North America, and are becoming more accepted in the US & Canada.

Organic Acid Technology (OAT)

OAT type uses organic acid technology rather than just silicates, phosphates and nitrates. OAT type antfreeze does not need nitrates to stop cavitation, so they are much more stable and last 3 or 4 times as long as the standard old style antifreeze. No testing required other than dilution ratio.

Hybrid Organic Acid Technology (HOAT)
The 3rd type is HOAT antifreeze. It uses mainly organic acid technology but with small amounts of certain silicates and phosphates. It also is as long lasting OAT type.

Colour means nothing. Every manufacturer adds their own colouring to differentiate their product(s). Their is no standard for colour, although the green usually means IAT type additives (but don't count on it)
 
Back
Top Bottom