Anti-freeze Filter

[a64pilot]

It's pretty common for larger engines to have an anti-freeze filter and if you use SCA precharged coolant that essentially coolant will last as long as the engine, just replace the coolant filter every year or so.
Has anyone installed an Anti-freeze filter system on their boat?
I'm flushing my coolant system now and there is more rust than I like, I've flushed as well as I can, but there is still some there, I have no issues with overheating or anything, but think a coolant filter is warrantied.

[MarkSF]

I was a bit puzzled about this until I found online that the filter itself is designed to release anti-corrosion additives as it is used. Therefore, you are right, regular maintenance is to simply change the filter.

Interesting!

Need Release® Synthetic Media Cooling System FiltersPenray

[model 10]

More and more stuff.

[a64pilot]

Originally Posted by Guy

More and more stuff.

It is, but it's simply cut the water heater hose and install, about as simple as simple gets.
Back to the old International Harvester farm tractors, they and other larger machines come with the filter pre-installed, just replace a filter once a year and the anti-freeze lasts forever, or at least a really long time.
My engine I believe to be low time, but old. I'm trying to make her last.
But in my case no matter how much I flush, I still have a coating of rust inside of the hoses and I'm sure everything else, I'm hesitant to use an acid flush like I would on a car as I found out my heat exchanger has a zinc sleeve on it covering the tubes, and acid and zinc don't mix well.
I assume this zinc sleeve is why my heat exchanger has no zincs.

[hellosailor]

It used to be that you could buy a little pint can of coolant additives (water pump lubricant and rust preventive, etc.) in any parts store, and just add that to the existing old a/f to keep it up to snuff. Now...it seems that no one even makes it any more!


Almost like a conspiracy to force replacement of the "permanent" a/f, since you can't just top up the additives any more.

[a64pilot]

You actually can buy the "SCA" additives, but they are usually now contained in the filters as it was usually the bigger "fleet" users that did that.
https://www.cumminsfiltration.com/ht.../supp_add.html

It's really the guys with wet sleeves that have more need of keeping their anti-freeze up to snuff as they will suffer from the sleeves pitting from cavitation. The sleeves ring like a bell when the engine is running, causing cavitation and cavitation of course causes pitting, just like it does on props.

This is the anti-freeze I use, notice the name
SCA Heavy Duty Coolant & Antifreeze - Fleet Charge | PEAKhd.com

[thinwater]

(I'm in the coolant industry)

a. You REALLY do not want to be adding and SCA filter to an engine unless you plan to closely monitor nitrite levels. There is also very nearly no chance that you need SCAs (assuming you are using long-life coolant) unless you are a work boat running 24/7. Over treating with SCA--whether through filter addition or liquid addition is worse than no SCA.

b. SCAs are only needed every few years in very heavy use (1000 hours with heavy use). The greatest chemistry risk, by far, to marine coolant systems is a tiny seawater leak. The condemning limit for chloride is only 50 ppm (seawater is 23,000 ppm), and thus most manufacturers recommend changing the fluids every 2 years, long before SCA is needed.

c. If you are seeing actual rust, you have another problem (stray current or an air leak--air is deadly as it contains oxygen) you need to solve. You do not need a filter.

d. ALL of the truck OEMs are moving to nitrite-free coolants (no SCAs) for a number of technical reasons (nitrite can form ammonia insitu in vehicle systems). Go to a nitirite-free heavy duty formulation and say good by to any thoughts of SCAs. Simpler.

e. While liner caviation is real, I think it is a tiny problem for small marine engines. This is usually seen on large turbocharged engines, often at higher altitude (lower pressure). And it will not be a problem if you change the coolant every few years. Not a flush, just a change.

[thinwater]

Originally Posted by hellosailor

... Now...it seems that no one even makes it any more!

Almost like a conspiracy to force replacement of the "permanent" a/f, since you can't just top up the additives any more.

No. The long life AF in general does not need SCAs, and the older coolants should have been rotated out of service. Given the risk of 0.2% seawater contamination, you need to change the coolant anyway. Additionally, SCAs do nothing to lower the breakdown products (glycolate/formate) that build over time.

[a64pilot]

Yes, I'm seeing rust, but am sure that is from the PO probably never changing coolant. I had one of the thermostat bolts frozen that I had to wring off and luckily it left enough I could get the rest out with a vise grip and chase the threads.
Last year I just drained and changed coolant.
I can live without the SCA and permanent coolant as I'll probably be cleaning the exchanger every other year or so anyway and not trying to save coolant would be easier.
Just filters with no SCA are available as well, I'm wanting to get the last of the rust out, so I may go with a filter in the heater hose, just leave the SCA out as there is apparently a need to change coolant on a regular basis anyway.


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