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Author Topic: Heat exchanger  (Read 674 times)

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saltygirl

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Heat exchanger
« on: June 18, 2017, 06:32:26 PM »

Has anyone cleaned their heat exchanger?  If so, how often do you need to clean it?
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Celeste and Greg Ray

mark_53

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Re: Heat exchanger
« Reply #1 on: June 18, 2017, 08:36:04 PM »

Usually you just replace it, but it can be cleaned if there is a compelling reason.
Make sure you check and replace your zinc often.
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1989 C34 Mk1

Noah

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Re: Heat exchanger
« Reply #2 on: June 18, 2017, 10:27:01 PM »

A lot of folks may have a different opinion about replacing vs reconditioning. Some have taken theirs to a radiator shop to have it "boiled out" /recondition.  You could also open up the end cap and check for and remove any broken pieces of zinc and/or crud. I opted to replace as it was pretty bad and didn't want the hassle. Now, unfortunately, I am having a bit of a mounting issue, which I have discussed in another thread.
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1990 hull #1014, San Diego, CA,  Fin Keel,
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Ed Shankle

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Re: Heat exchanger
« Reply #3 on: June 19, 2017, 07:08:19 AM »

$40 bucks to acid wash (often termed "boil out"), vs $350 for a new one. Unless you have structural problems with it, acid wash is the way to go. Look for "radiator repair" in your local area to find someone that does the acid wash.
Regards,
Ed
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Ed Shankle
Tail Wind #866 1989
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KWKloeber

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Re: Heat exchanger
« Reply #4 on: June 19, 2017, 09:59:16 PM »

Has anyone cleaned their heat exchanger?  If so, how often do you need to clean it?

depends on the "sea" water conditions, amt of scale deposited, etc.

Inspect it first.  If there's no deposits/corrosion etc, then leave it alone.  if temp slowly creeps higher, then consider cleaning the tubes out as recommended below)

In the great lakes I was more likely to develop a pinhole leak between the sea water and freshwater sides (I did after 20 yrs and replaced it) than ever need to clean it.

You can also clean it yourself CAREFULLY using an acid scale remover (big box store)  or a SAFE product like RydLime.


ken
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Twenty years from now you'll be more disappointed
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So throw off the bowlines.
Sail away from the safe harbor.
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Explore. Dream. Discover.   -Mark Twain

pablosgirl

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Re: Heat exchanger
« Reply #5 on: June 23, 2017, 06:41:14 PM »

I take mine out every year.  I inspect it and replace the zinc. soak it in RydeLime.  I also rod out the tubes with a wire coat hanger.  Paint it and put it back in.  Make sure to "burp" the cooling system to avoid air pocket and over heating.
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Noah

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Re: Heat exchanger
« Reply #6 on: June 23, 2017, 07:40:54 PM »

Hard to wrap my head around on many levels:
1. Do you have a freshwater boat? As rule of thimb is to change zinc 4 times a year in saltwater.
2. Remove, ream-out and paint EVERY YEAR seems excessive!?
3. Never been inside one, but how do you get a coat hanger to bend around inside tubes??
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1990 hull #1014, San Diego, CA,  Fin Keel,
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Stu Jackson

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Re: Heat exchanger
« Reply #7 on: June 24, 2017, 11:43:36 PM »

I have been a proponent on inspecting your HX regularly, but some of this seems excessive and OCD.  :D

The tubes should remain clean because that's where the water moves the fastest.  If you don't use your boat, then water sits in the tubes.  Using your boat cleans the tubes.  That's how they were designed.   If saltwater sits int he tubes, not so great, but certainly less an issue than than the salt precipitates that DO fall out at and start to block the inlet port of the HX from the rw pump, which has been my experience.

I agree with Noah that changing zincs before they deteriorate is essential.  I used to have to do them every 3 months, too, back in Northern California, but moving north I find they now last 6 months.

Your boat, your choice.  :D

PS - The 101 Topics has some discussion links about this.
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Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

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Ron Hill

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Re: Heat exchanger
« Reply #8 on: June 25, 2017, 02:47:55 PM »

Guys : There have been a number of posts on this topic.  Be careful what product you use so it's not harmful to copper or bronze.

I used "Lime-A-Way" once a year and it pretty well kept the calcium deposits down and the cooling temp stable. 
I'd take a small funnel and squirt in some LAW let it flow in squirt in, some more etc.  Let it set about 30 minutes and then reconnect.
 
I also made sure that when we docked and were leaving the boat for a week or so I would run fresh water thru the entire raw water system - by putting the raw water hose off the thru hull, connecting an extension  and putting it in our ice chest - running the engine which emptied the ice chest and put fresh water in the entire system.

A few thoughts
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Ron, Apache #788

KWKloeber

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Re: Heat exchanger
« Reply #9 on: June 27, 2017, 04:49:36 PM »

Guys (and gals)  From years involved on the peripheral with fighting sale in pumps, heat exchangers, boilers --  The "best" scale remover (in terms of not attacking the metal, personal safety, etc.) is not a very low pH acid like LAW (like pH 0.1 !!!!!!) , but RydLyme.

BTW, the MSD sheet for LAW lists incompatible materials -- "METAL"  !!!   I don't know anyone who works for who makes of  RydLyme, or who sells it beside the local dealer by me -- so I have no dog in the product.  I DO have a dog having been burned skin from low pH products, and Rydlyme is safe to skin, is biodegradable, and whatnot else.  I would really caution against using highly acidic products for other than very light cleaning of metal.

One key to effective Hx cleaning (or anything), is to keep the descaler moving across the surface.  Setting up a small pump to keep descaler circulating is better than dumping acid into a container and letting it eat up the scale (and any metal next to the scale.)  What happens when you let descaler sit and work is, what's right against the surface gets equalized with the scale and quickly becomes ineffective.  Keeping the descaler flowing (and thus fresh descaler always against the surface of the scale) is how to avoid that "equalization" from occurring.

JTSO, YBYC, and so on...
kk
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Twenty years from now you'll be more disappointed
by the things you didn't do, than by the ones you did.
So throw off the bowlines.
Sail away from the safe harbor.
Catch the tradewinds in your sails.
Explore. Dream. Discover.   -Mark Twain
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