Best Type of antifreeze to use.

[CoachDePo2]

I have a 1991 Cobalt 222. I was wondering what is the best marine antifreeze to use. I was told by the marina where I take my boat that RV/marine antifreeze isn't the best thing to use. The suggested something -50? to -100?. Any advice would help thank you!

 

[GA_Boater]

Welcome aboard.

The best antifreeze to use is air. Do a proper drain of the block and manifolds, unless a Cobalt 222 is outboard powered.

How cold does it get in your neck of the woods? More broken blocks occur when using antifreeze than air because the antifreeze method doesn't ensure that any water in the block is mixed well with A/F. Unmixed -100 A/F will allow pockets of water to freeze.

BTW - RV antifreeze does come in -50 and -100 protection levels. Your marina want's to sell you something. That's not bad, but you can save money by avoiding them and doing it yourself.

 

[poconojoe]

Do you have a raw water system or a closed system? If raw water ( takes cooling water from the lake or sea), then do what GA_BOATER said.

 

[Scott Danforth]

drain everything. poke around in the drain holes to make sure that you have everything out and there is no sand or crud blocking the ports. make sure you pull the large hose of the ciruclating pump. also drain the power steering cooler (it has a drain too) Change all the fluids and filters. if you have a bravo or VP drive, pull the hoses from the raw water pump as well

the boat is now winterized.

then if you want to pour AF in the block, put all the drain plugs back in, pour in -100 degree RF (Propylene Glycol) into the thermostat housing with a funnel

 

[Bondo]

I was wondering what is the best marine antifreeze to use.

Ayuh,....Welcome Aboard,..... Use Air,.... It never freezes on our planet,.....

 

[oldjeep]

Air may not freeze, but you won't be poking around for rust flakes when you drain it if you store with antifreeze. For modern engines with knock sensors it really helps keep them from rotting as well. Camco banfrostt is what I fill mine with after I have drained all water.

As for where to fill it, pull the 2 big hoses off the thermostat housing and fill through the hoses. One will fill the block, the other will back fill to the drive

 

[tpenfield]

The RV/Marine stuff comes in 3 flavors

Pink = - 50 F Bursting Point

Purple = - 60 F Bursting Point

Blue = -100 F Bursting Point

They will typically become 'solid' at about 20 degress higher than the bursting point.

You should have your Marina elaborate on why they don't think the RV/Marine stuff is the best thing to use.

Do they favor air?

Do they not recommend the pink stuff?

 

[wrvond]

Where your boat is located and how it is stored is important information.
I keep my boat on a trailer at home. Winterizing includes blowing out the potable water lines to the galley and head, cycling pink stuff through the toilet, placing a boat heater in the engine compartment, and shrink wrapping the whole thing.
As noted, RV/marine antifreeze does come in -50? to -100? flavors, so I wonder what they are trying to sell...

 

[oldjeep]

The RV/Marine stuff comes in 3 flavors

Pink = - 50 F Bursting Point

Purple = - 60 F Bursting Point

Blue = -100 F Bursting Point

They will typically become 'solid' at about 20 degress higher than the bursting point.

You should have your Marina elaborate on why they don't think the RV/Marine stuff is the best thing to use.

Do they favor air?

Do they not recommend the pink stuff?

Well, you can't count on the color. The camco banfrost -100 is redish not blue

 

[CoachDePo2]

I'm in western Pa. I store my boat in a non-heated garage. Normally I use the RV/Marine antifreeze. I'm going to look into draining and blowing everything dry. I was told to run it with Water through the muffs until the thermostat opens up then putting the antifreeze in. Is this correct? I have never had any problems before but a few years back a cap fell out. No damage to the block and put it back in and everything has been fine. Just trying to do it the right way. Thanks this information has been very helpful.

 

[oldjeep]

I'm in western Pa. I store my boat in a non-heated garage. Normally I use the RV/Marine antifreeze. I'm going to look into draining and blowing everything dry. I was told to run it with Water through the muffs until the thermostat opens up then putting the antifreeze in. Is this correct? I have never had any problems before but a few years back a cap fell out. No damage to the block and put it back in and everything has been fine. Just trying to do it the right way. Thanks this information has been very helpful.

The cap didn't "fall out" - you got lucky and a core plug popped when water froze in your block.

That way is a gamble since your engine is full of water and then you have to pump and waste gallons of antifreeze through it. Drain the block and heater if you have one and then pour in the antifreeze through the heater lines and the large hoses on your thermostat housing.

 

[CoachDePo2]

I have never drained the block before. I have to look into how to do that. I lack experience with them. I haven't had the boat in the water since early August. Usually I just flush the engine with antifreeze without running the water through it 1st. Just trying to figure out the best way to do this so I don't have any problems. Thanks for the advice.

 

[Scott Danforth]

I'm in western Pa. I store my boat in a non-heated garage. Normally I use the RV/Marine antifreeze. I'm going to look into draining and blowing everything dry. I was told to run it with Water through the muffs until the thermostat opens up then putting the antifreeze in. Is this correct? I have never had any problems before but a few years back a cap fell out. No damage to the block and put it back in and everything has been fine. Just trying to do it the right way. Thanks this information has been very helpful.

caps or core plugs dont just fall out. they are pushed out because water freezes and expands. I bet you have a crack in your blocks water jacket

if you dont drain and try to suck up antifreeze, the thermostat slams shut and the waterpump just pushes it out the exhaust. so the block is still filled with pure water and all your antifreeze just went out the exhaust. thats how the thermostat works

I have never drained the block before. I have to look into how to do that. I lack experience with them. I haven't had the boat in the water since early August. Usually I just flush the engine with antifreeze without running the water through it 1st. Just trying to figure out the best way to do this so I don't have any problems. Thanks for the advice.

the manual states drain = winterized. as an optional step for long duration storage optional antifreeze can be poured into the thermostat housing.

 

[Starcraft5834]

Welcome aboard.

The best antifreeze to use is air. Do a proper drain of the block and manifolds, unless a Cobalt 222 is outboard powered.

How cold does it get in your neck of the woods? More broken blocks occur when using antifreeze than air because the antifreeze method doesn't ensure that any water in the block is mixed well with A/F. Unmixed -100 A/F will allow pockets of water to freeze.

BTW - RV antifreeze does come in -50 and -100 protection levels. Your marina want's to sell you something. That's not bad, but you can save money by avoiding them and doing it yourself.

LOL. first sentence says it all GA. nice! best antifreeze method is to have nothing that will freeze...

 

[Watermann]

I use non freezing air and not anti-freeze, drain manifolds, block (poke the drain holes to clear debris), pull power steering raw water intake hose, lower water pump hose. Takes a half hour is all.

Oh and there's no rust flakes either.

 

[frantically relaxing]

Our Chaparral 260ssi had a hot/cold shower, so the one block drain already had a hose on it. So I put one on the other side and on the SB riser. The alternator was in the way of getting a hose fitting on the port riser, but the plug was very easy to get at. Piece o' cake to drain the block & risers...

The Regal also has block drain hoses, with capped garden-hose ends. Riser plugs are all EZ access. If I want to antifreeze after I drain, I can just fill the blocks from the bottom up using the same onboard pump and antifreeze pumped thru the fresh water system.

But I too use airnofreeze.

 

[poconojoe]

But I too use airnofreeze.

"Airnofreeze" that's hilarious!

 

[JimS123]

if you dont drain and try to suck up antifreeze, the thermostat slams shut and the waterpump just pushes it out the exhaust. so the block is still filled with pure water and all your antifreeze just went out the exhaust. thats how the thermostat works

/QUOTE]

That's probably completely untrue unless you live in Figi. Chances are the gallon jugs are warmer than the city water pumped thru your hose, so the TS will open.

But, to completely answer the OP's question, there are 2 types of marine anti-freeze. All are prop gly based, not green ethyl based you might use in a car. Oner is for marine water systems (the sink), and the other for the engine. The engine variety is more expensive and specifically states on the bottle that it has additives for engine use.

Not a bad idea after you drain to keep the TS and all internal parts immersed in the good stuff.

 

[bruceb58]

But I too use airnofreeze.

I am stealing that phrase.

Airnofreeze™?

But you need the trademark symbol after it.

 

[JASinIL2006]

My antifreeze* is mostly nitrogen and it's good to about -346 degrees Fahrenheit. After that, all bets are off!

*antifreeze = air