coolant/anit-freeze mix for tropics?

[micoverde]

Does anyone have any data on the 'ideal' mix for coolant to water for engines running in tropical conditions? Do date i've been using around 50/50 but I think this might be taking something away from the cooling abilities - was wondering if 30% anti-freeze/coolant would still be enough to keep corrosion at bay.

-Warren
SY Mico Verde
Mico Verde Yacht Sailing Blog Journals

[CSY Man]

Have been using 50/50 Preston and water for years. No problems, no corrosion. (Engine is 28 years old and still going strong)

That being said, some diesel mechanic recommended using distilled water for the mix...never heard that one before....

Anybody?

[Alan Wheeler]

50/50 is fine. The main purpose of using an additive is to inhibit corrosion. Anti-freeze, at least good ones, have all sorts of additives in them. Corrosion inhibitors are just one. But they also have "wetting" agents. This ensures a good "bond" of water to metal components and aids cooling by wicking that heat away even more economicaly. Plus the glycol raises the boiling point of the water, So anti-freeze can also be called anti-boil as well. I highly recomend 50/50 mix in any temperature. No higher as tehn the is not enough water in the sytem to make the Glycol work properly. It is the glycol/water mix that makes it work.

[merlin]

/\/\ I can't say for boat engines as I don't have much experience with them. But the similarities to car engines are big and small. For car engines is responsible for MOST of the cooling of the engine and the antifreeze (commonly also called coolant) is really just there to keep the mixture from freezing in cold temperatures.

50/50 is usually the best mix for most climates. The most I've heard people go is 70/30 (that's 70 water, 30 antifreeze) or somewhere in between. Obviously you don't want the water to freeze.

As far as what type of water, distilled water is highly reccomended becuase regular water is typically full of contaminants that can cause corrosion. When I do a flush, I usually will do the following:

* drain system
* fill with 100% distilled water
* run to operating temperature
* drain
* repeat above until fluid comes out fairly clean
* now mix (or buy premixed) and fill with final soluion
* Run with radiator cap off (keep in mind this is for the car) to burp the system (air should escape, air has no cooling properties)
* top off
* keep topped off.

You can get distilled water at just about anywhere, make sure you buy a lot if you're going to flush the coolant. Around here it's <.75 USD per gallon.

I know most of this is from my car knowledge, but I hope it helps a bit!

Here is some more information:
Coolant - Wikipedia, the free encyclopedia
and
Ethylene glycol - Wikipedia, the free encyclopedia (what most antifreeze is)

[GordMay]

I wouldn’t deviate from the engine manufacturer’s recommendations (generally to use 50:50 glycol/water coolant) unless I encountered hot climate problems, in which case I’d reduce the glycol content to not less than 25%.

Water has a higher specific heat than glycol(s) (Water = 1.0, whereas Ethylene Glycol ≈ 0.57, & Propylene Glycol ≈ 0.59); but (as noted by others) there are many other important additives* in anti-freeze/coolant fluids.

Has anyone used surfactants, like “Water Wetter”?
Red Line Oil: Coolants and Others

* Which improve the coolant's properties in respect of latent heat, vapour pressure, boiling point, and viscosity (surface tension), etc ...

[Alan Wheeler]

Has anyone used surfactants, like “Water Wetter”?
Red Line Oil: Coolants and Others

Some of the "good" anti-freeze products have them as part of their additive pack.

[hellosailor]

Warren-
Any auto parts store will have cans of "water pump lubricant and..." on the shelf. Usually 8oz. or pint cans, and that contains the lubricants and anti-corrosives that a cooling system needs. If you use regular antifreeze mix, usually you'd add one of those cans every second year instead of changing the fluid.
You might consider refilling with distilled or deionized water (stops the long-term corrosion mysteries) and a pint or two of the additive, if you don't want to use antifreeze.
If you do use antifreeze--don't get the "antileak" kind unless you need it. The antileak ingredient is usually sodium silicate (waterglass) and it forms an inert mineral coating on all the metal parts, which prevents leaks--but also inhibits cooling.
Also avoid the new "permanent" orange color AF unless you flush your system first, apparently there are some problems if the new stuff and old stuff mix and they are accused of attacking engine head gaskets when that happens. Not a good thing to risk.

[SurfNRG]

I understand that it's very important that you use Silicate free anti-freeze mixed 50/50 with distilled water or buy the premixed solution. And this is after flushing out your system with Distilled water. Merlin's procedure sounds legit.

[Therapy]

Originally Posted by SurfNRG

I understand that it's very important that you use Silicate free anti-freeze mixed 50/50 with distilled water or buy the premixed solution. And this is after flushing out your system with Distilled water. Merlin's procedure sounds legit.

Ditto!
Tap water is full of all kinds of CRAP!!

[fcsob]

I use Redline Water Wetter in all my engines.It releases the serface tension in the cooling system taking away hot spots in you cylinder head.They also make Diesel Water wetter without lubrication additives. Water is a better coolant than anti freeze. The purpose of anti freeze is to lubricate & just what it says anti freeze.When we raced we lowered our coolant temp by 25 degrees with water wetter & deionized water. Yuo can by deionized coolant over the counter at parts stores.

[hellosailor]

The deal with silicates is that sodium silicate (aka "waterglass") is used to STOP PINHOLE LEAKS and prevent corrosion. It does this by precipitating out and forming an almost inert "glass" coating on the internal passages.

Now that's fine for stopping corrosion and pinhole leaks, but the glassy coating inhibits heat transfer, and CAN also eventually flake off and plug up small cooling passages in radiators and condensors.

Great for fixing specific problems--but totally unnecessary in a proper cooling system and an extra source of potential problems.

In most of the US you can buy deionized water, which is just as good as distilled for these purposes, for about $1.50 per gallon in any supermarket. Sold with the laundry supplies, because it is used in steam irons. It doesn't leave behind any clogging deposits.

Water wetter can be a good idea (although good antifreeze will have something similar already in the right proportion in it) as is "water pump lubricant" which replaces some of the components that normally age out of antifreeze.

Dunno how the new orange "permanent" stuff is versus that.

[windsaloft]

Just did a good flush and refill ---- several of the excellent diesel mechs in the area have said use distilled water for the clean and flush efforts b/c of the minerals to be found in tap water. And, for the 50/50 mix at the end, distilled water as well.

One thing we learned about --- Shell Coolguard has "Bitterguard" added so that if there is a leak in our coolant/freshwater interface in the Seaward Hot Water Heater (uses engine freshwater cooling system to heat our water), there is a very bitter taste. Problem is, Shell's label says the bitter taste goes away unless you use the coolant full strength --- but it is still a good idea. The bitter taste is also supposed to discourage animals from lapping it up, and it is supposed to be less toxic that general automotive coolant...........for what that is worth. This stuff is orange --- is this the stuff you are talking about?

[hellosailor]

Dunno about that Shell product in particular, but for the last few years there have been "permanent" "less toxic" antifreezes on the market that are usually orange to distinguish them from the older green/blue products. (And some issues if the two are mixed in the same engine.)

[GordMay]

Originally Posted by hellosailor

Dunno about that Shell product in particular, but for the last few years there have been "permanent" "less toxic" antifreezes on the market that are usually orange to distinguish them from the older green/blue products. (And some issues if the two are mixed in the same engine.)

Since antifreeze is clear when it is manufactured, and water is clear, dye is used to colour the antifreeze for identification, and marketing purposes. The colour of antifreeze is no longer an accurate indicator as to whether it is an IAT, OAT, HOAT or NOAT formulation.
Different manufacturers may use different dye colours delineating different chemisties.

The Colour of Antifreeze:
http://www.filtercouncil.org/techdata/tsbs/05-2.pdf

[The Mons]

We have moved from a 50 /50 solution to 60 distilled / 40 non-toxic poly-glycol mixture. We did this due to some overheating issues that we experienced in the south during the warmer months. I spent a lot of time tearing down the heat exchanger before coming to this solution.

One thing that I have always been curious about is that a lot of people still use some sort of toxic antifreeze although they may have a heat exchanger water heating system.

Having the Shell Bitterguard additive is a step forward, but not a failsafe solution. All it takes is a pin hole in the tubing to contaminate the water in the tank. Even though we don't really use the water tanks for drinking, I would prefer to keep toxins out of the system anyway.