Salt-Away for Closed Cooling System Flushing . . .

[tpenfield]

My cooling system issues of last year schooled me a bit on heat exchangers and calcium (salt) build-up inside them.

I have twin 7.4 MPI engines with aftermarket FULL closed cooling systems. . . Bravo 3 outdrives. . . Ocean boating.

This year as part of my end-of-season maintenance I figured that, as a preventative measure, I would run some Salt-Away through the sea water side of the cooling systems. So, after Googling a while and reading the Salt-Away product information, I made up a couple of 3 gallon batches of 15% Salt-Away and sucked it into the cooling system (i.e. oil coolers, heat exchanger and exhaust elbows) and let it sit for a few hours. I figured that 3 gallons was about enough to fill the sea water side of the cooling systems, as the Salt-Away (blue in color) was just starting to show in the exhaust water.

Then, after waiting a few hours, I ran regular water through the system for about 5 minutes to flush out the Salt-Away.

I was initially considering using CLR as a less expensive approach, but the CLR product information said not to use it on brass/aluminum/copper I'm not sure what it would do to those metals, but by contrast, the Salt-Away is recommended for use with all metals and particularly closed cooling systems/heat exchangers.

I'm not sure if other folks do a similar thing with their I/O engine and closed cooling systems, or even an open cooling system I/O. Most of the searching that I found was folks flushing their outboards with the stuff.

Thoughts/comments?

 

[Scott Danforth]

I flush with salt-away on the muffs every time out, however I am trailered where you are slipped. I have been meaning to get a neutra-salt setup. something like this may be of value

as you come in to dock, press the button for 45 seconds and shut off.

http://www.volvopentastore.com/Neutra-Salt-Engine-Flushing-Kit/dm/store_id.366--view_id.352393

 

[alldodge]

Have no opinion but found this thread where DonS used neutral salt, then used the same system but used salt away instead and noticed no difference

http://forums.iboats.com/forum/engi...-outdrives/572997-neutra-salt-flushing-system

 

[Scott Danforth]

I knew the solutions were similar other than color, thanks for the link, it is the one I remember comparing them

the salt-away plastic hose end thingy is a bit of a pain.. its the solenoid, tank, plumbing, etc. like the neutra-salt system that I want to pick up and install (will probably grab a windshield washer fluid reservoir and pump) I will most likely be injecting into the drain location on my oil cooler and letting the raw water pump take it from there vs the tee fitting as im running out of realestate

 

[tpenfield]

I would image that both products do about the same sort of thing as far as getting rid of the salt and not killing the fish.

FWIW - I ran the engines today after having done the salt-away 'treatment', and brought them up to temperature under the same conditions as yesterday. Both engines run a few degrees cooler after the salt-away treatment :thumb:

So, I guess I'll make this an annual thing.

 

[Lou C]

Nice thanks for the info Ted. I have wondered about this for a while; like filling the engine and manifolds after draining for winterizing is it actually worth it. Seems like it is....
BTW I noticed that with the re man heads and new exhaust my engine runs cooler on the water hose, like around 150 or so it used to be 160-165. I bet the old heads had some cast iron clogging due to corrosion..

 

[semperfussy]

i am ready to put my 21' 1974 Wellcraft boat into storage for the winter. the boat has a 1974 mercruiser 188 engine (ford 302 engine), I only put on about 8 hours on this boat this year. Do I have to change the oil filters and water separating filter after I change the oil or is it okay to not change the oil and filter?

 

[tpenfield]

semperfussy Welcome to iBoats. You should start your own thread to ask a question, rather than hi-jacking someone else's thread.

 

[tpenfield]

Another closed cooling 'thing' that I did as preventative maintenance was to check the strength of the coolant in the closed system.

I did this because I have used over the past several years a variety of pure and pre-mixed anti-freeze/coolant on the engines, so I was not sure where things stood from a freeze protection perspective.

I drained a sample of the coolant from an exhaust manifold of each engine and used a coolant AF tester to see the freeze point protection of the coolant.

Here is the Port engine sample . . . Looks good . . . protection to about -40 F. (also -40 C)


The starboard sample was a bit weaker . . .


Probably only good to about -10 F ( -25 C) or so . . .


The winters on Cape Cod do see temps as low as -10 F, but not much more. I drained down the coolant on the Starboard engine, added a gallon of pure AF, ran the engine, let it cool, and re-tested it. The protection is now in the -25 F range.

 

[Lou C]

Ps for anyone who wants to use marine PG antifreeze to winterize the raw water side by draining and back filling, there is an alternative to the super expensive -100 (rated burst temp, the freeze temp of this is about -60) stuff WM sells. The -50 starts to get hard at too high a temp for my liking and so does the -60.

Here in NY at least you can buy Sierra brand automotive antifreeze but it is PG non tox stuff. So if you buy a gallon of this @ about $12 a gallon, you can mix it 50/50 with water and get about -25 F freeze protection and the cost is less than half of the WM stuff. You can mix it stronger if you want but that is adequate for 'normal' climates.

 

[tpenfield]

I found some -75 F at Wallymart . . . it was only about $6/gallon vs. the $15/gallon -100 F stuff that West Marine sells

 

[Lou C]

Wonder what the freeze temp on that one is Ted, -75 is the bust rating, correct?
​I picked up a couple of PG hydrometers some years back because you can't check the freeze temp of PG antifreeze with a hydrometer for EG antifreeze. Sierra sells the ones with the little floating balls. 4 balls and I think you're good.

 

[tpenfield]

Wonder what the freeze temp on that one is Ted, -75 is the bust rating, correct?
​I picked up a couple of PG hydrometers some years back because you can't check the freeze temp of PG antifreeze with a hydrometer for EG antifreeze. Sierra sells the ones with the little floating balls. 4 balls and I think you're good.

​Yes . . . like the other variations, the -75 F is the burst rating. as is the -100 F stuff. So, I figure the freeze point is about half way between what you would get with the -50 vs. the -100 varieties.

​My prior testing of the -50 stuff showed that it gets slushy at around -15F, or 35 degrees above the bursting point. All things being equal, I figure the -75 stuff will get slushy at around -40 F . . . should be fine for my area, (Cape Cod) where we rarely see anything below -10F.

 

[Lou C]

True here in Long Island our climate is similar, we rarely even get down to zero. In the Pine Barrens out east they get a good deal colder, our proximity to LI Sound keeps us warmer. I'd love to see a test, to see if filling the raw water side of the cooling system with AF with corrosion inhibitors actually helps. This is always a big debate but Mercruiser clearly states in their shop manuals that it does help.