Cleaning Heat Exchanger

[ranger58sb]

For the mains, our heat exchanger has a pencil zinc, and the aftercooler has two -- so if using most flushing products through our whole raw water system, all three for each engine would need to be managed. Replace afterwards, or remove/plug/reinstall...

Our genset heat exchanger has one zinc, ditto management.

-Chris

 

[Bendit]

Bendit

That sounds really good for ease of use and environmental protection.

Have you seen before and after inside the HE for visual proof that white vinegar really worked well?

Also, what effect on pencil zinc does white vinegar pose? With other cleaners mentioned pencil zinc was to either be removed prior to cleaning and replaced thereafter (recommended by manufacturers). Or it would get eaten up by cleaner (reducing cleaner's overall capabilities) and replaced thereafter.

Thanks, Art

Yes, I've checked both the main and genset HEs after vinegar (removed end caps) and they were both completely clean. Last time, after two years, temp at WOT dropped by 5 deg C.
Vinegar doesn't affect zincs but, I had removed them and plugged holes when filling with vinegar and then put in new ones.

 

[Underway]

Slightly off topic, but associated with cooling....on the trip across Lake Michigan just prior to putting the boat up for the winter, I noted that one engine was running hotter than the other...within limits, but about 10 degrees difference. As I had noticed the water flow from that engine's exhaust was less than for the other, I decided to change both raw water pump impellers (they were "due" anyway). Turned out that the warmer running engine had a 10 vane impeller and the cooler running engine had an 8 vane impeller. The one with 10 vanes had been overhauled by a well known pump rebuilder a couple years ago and installed as I received it.

Both were replaced with 8 vane impellers. When I restarted the engines for leak checks, the flow on the "hotter" engine was noticeably improved and appeared to match the other engine. Don't know yet if I solved the temperature disparity as the boat was idled straight over to the Travel lift and put to bed, but I thought I'd share the info. Eight vanes appear to flow more water than ten...

 

[Art]

Yes, I've checked both the main and genset HEs after vinegar (removed end caps) and they were both completely clean. Last time, after two years, temp at WOT dropped by 5 deg C.
Vinegar doesn't affect zincs but, I had removed them and plugged holes when filling with vinegar and then put in new ones.

WOW! - Cool!! - Thanks!!! White Vinegar it is then... I shall eventually try it.

 

[cappy208]

Muriatic Acid works. Available at HD and Lowes. Wear eye and hand and skin protection. Only takes about 5 minutes to clean out the exchanger.

Then inject orange juice to neutralize the acid. Then rinse with water. done.

There is the issue of pouring a gallon of muriatic acid in the ocean..... I clean exchangers in the driveway, and reseal the muriatic acid. then it goes to hazmat collection facility. Never actually done one like you did. Hey, if you found a product that is labeled 'safe for the environment' use it. But, in my experience, if it is labeled such, it usually isn't as 'good' as the real stuff.

 

[Art]

Fellas, this conversation is over my head. Would someone tell me what zincs, you are talking about? The only ones I have in my minds eye are the one's on the rudder, shaft, & hull, all below the water line.

Tonto

Heat Exchangers' raw water portion have what is called a "pencil zinc" (shape somewhat resembles a pencil).

This anode is to stop internal electrical charge disintegration of the metal parts, called diode. A must in salt water... should be used in fresh also. Get on Google and you can locate info regarding this. Also, use TF search feature. There are plenty posts about pencil zincs. And, discussions about anode/diode.

 

[Art]

Muriatic Acid works. Available at HD and Lowes. Wear eye and hand and skin protection. Only takes about 5 minutes to clean out the exchanger.

Then inject orange juice to neutralize the acid. Then rinse with water. done.

There is the issue of pouring a gallon of muriatic acid in the ocean..... I clean exchangers in the driveway, and reseal the muriatic acid. then it goes to hazmat collection facility. Never actually done one like you did. Hey, if you found a product that is labeled 'safe for the environment' use it. But, in my experience, if it is labeled such, it usually isn't as 'good' as the real stuff.

cappy - I have decades experience using muriatic acid for several reasons on various materials. Yesterday one of my crews used 2.5 gallons. It eats (dissolves) many metals. I'd be very careful what percentage you use and how long you leave it in. It loves to degrade metal surfaces and to eventually dissolve it completely. Pin holes in thin metal before complete metal failure are one of its favorite opening acts.

 

[TONTOROSS]

Art - Thank you. I was on Google when your post came in. I also found many post in the "history" frm as far back as 2010. Lots of info you folks have & is greatly appreciated. My memory is horrible, so per suggestion frm TH staff I'm saving the post. Everyone have a good evening. Tonto.