Cleaning heat exchanger

Apr 5, 2009
3,072
Catalina '88 C30 tr/bs Oak Harbor, WA
Any suggestions on how to clean out a copper heat exchanger? I have removed my 3"ø x 13" heat exchanger for cleaning and planned to take it to the local radiator shop for cleaning but he has quoted me $150 which I consider to be ridiculous.
The same shop did it in 2008 and charged $80 and at that time. In 2008 I had very bad overheating problems and removed the HX and found many of the tubes to be completely pugged. I decided to be proactive and clean it before I have any problems. I checked the tubes and only two have any blockage and that is only about 1" at the end.
 
Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
That's a really good price since my diesel boat mechanic quoted me $1800 last October, although I recognize that price increase is higher than the CPI increase from 2008 to 2020 of 1.17.
 
Apr 5, 2009
3,072
Catalina '88 C30 tr/bs Oak Harbor, WA
This is not the price to R&R with cleaning. That is the cost just for cleaning only. I would need to deliver and pick up the HX at the radiator shop which is 30 miles away.
 
Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
Consider cleaning (pickling) it yourself with a descaler like Barnacle Buster as shown in the youtube videos or methods and solutions discussed in the threads below?

and How To Clean The Heat Exchanger On Your Boat's Engine
 
Jul 7, 2013
35
Catalina 34 856 hamilton
I recently boiled mine in muriatic acid from lowes. probably not nearly as good as a radiator shop can do, but it got fairly clean on the inside. i hit it with some scotch brite pads and two coats each of high temp primer and paint.
 
Jun 21, 2004
2,765
Beneteau 343 Slidell, LA
Cleaned mine using a rifle bore cleaning rod with associated brush (22 caliber brush) attached to the rod. Maybe not as good as a radiator shop; however, it cleaned and descaled adequately.
 
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Jan 19, 2010
12,553
Hobie 16 & Rhodes 22 Skeeter Charleston
I recently boiled mine in muriatic acid from lowes. probably not nearly as good as a radiator shop can do, but it got fairly clean on the inside. i hit it with some scotch brite pads and two coats each of high temp primer and paint.
I would not recommend hydrochloric acid (muriatic) on any metal part other than copper. Hydrochloric acid will dissolve most metals (copper is an exception) and make the tubes thinner and more prone to rupture. I would recommend using acetic acid or phosphoric acid if your heat exchange is something other than copper.
 
Apr 5, 2009
3,072
Catalina '88 C30 tr/bs Oak Harbor, WA
I would not recommend hydrochloric acid (muriatic) on any metal part other than copper. Hydrochloric acid will dissolve most metals (copper is an exception) and make the tubes thinner and more prone to rupture. I would recommend using acetic acid or phosphoric acid if your heat exchange is something other than copper.
The heat exchanger is copper but I am sure that it has other metals in the mix. I will look for some acetic or phosphoric acid.
Dissimilar metal (credit Maine Sail Marine How To.)

10DissimilarMetals.jpg
 
Jan 22, 2008
1,661
Hunter 34 Alameda CA
I found on my Yanmar 3GMF heat exchanger (bronze) that a very long 1/4" drill bit passes through the tubes with a loose fit. Every couple of years I pull off the front cap and leave everything else in place. I use the bit on my cordless drill to ream out each tube. It reduces the scale to a fine powder which flushes right out upon reassembly and start up. I bought the bit at Harbor Freight

The rifle bore cleaning method is good too.
 
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Apr 5, 2009
3,072
Catalina '88 C30 tr/bs Oak Harbor, WA
I found on my Yanmar 3GMF heat exchanger (bronze) that a very long 1/4" drill bit passes through the tubes with a loose fit. Every couple of years I pull off the front cap and leave everything else in place. I use the bit on my cordless drill to ream out each tube. It reduces the scale to a fine powder which flushes right out upon reassembly and start up. I bought the bit at Harbor Freight

The rifle bore cleaning method is good too.
I read on another thread a suggestion to use a grinder to round or dull the corners of a bit so that it could not cut into the tubes which sounds like a good idea. I would also probably use a dremal to dull the edges of the flutes for the same reason.
 
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jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,746
CAL 35 Cruiser #21 moored EVERETT WA
Mine was Brass with copper. Radiator shop charged $65. Came back painted, pressure tested, ready to install.
 
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Apr 5, 2009
3,072
Catalina '88 C30 tr/bs Oak Harbor, WA
Mine was Brass with copper. Radiator shop charged $65. Came back painted, pressure tested, ready to install.
I wish! the only radiator shop within 60 miles wants $125 to $150 and that is only for clean and pressure test and it is returned bare copper!
 
Sep 25, 2008
961
Macgregor & Island Packet VENTURE 25 & IP-38 NORTH EAST, MD
Soaked mine in a tub of white vinegar. Used a plastic bristle bore brush to get inside the tubes. It did an ok job, as it wasn't too crusty inside the tubes.
 
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Oct 24, 2010
2,405
Hunter 30 Everett, WA
+1 for the bore cleaning kit. It's easy, fast, cheap, and no worries about eating up the metal.
Ken
 
Apr 5, 2009
3,072
Catalina '88 C30 tr/bs Oak Harbor, WA
A bore leaning kit is a good suggestion but the tubes on my heat exchanger are 5/32" which would be less than 15-caliber and I have not seen any kits that go that small. I also have about a dozen of the 68 tubes that are partially obstructed by the dividers and/or lip around the edge of the outer tube.
I got a 12" long 5/32" bit and dulled the corners and flutes which I was able to use to hand drill out all of the unobstructed tubes and will use some phosphoric acid to see what else I can get out.
 
Jan 25, 2011
2,435
S2 11.0A Anacortes, WA
A bore leaning kit is a good suggestion but the tubes on my heat exchanger are 5/32" which would be less than 15-caliber and I have not seen any kits that go that small. I also have about a dozen of the 68 tubes that are partially obstructed by the dividers and/or lip around the edge of the outer tube.
I got a 12" long 5/32" bit and dulled the corners and flutes which I was able to use to hand drill out all of the unobstructed tubes and will use some phosphoric acid to see what else I can get out.
Sounds like you got it covered. You could also try Piston Service in Anacortes. They are an auto parts shop with a machine shop. Also, Ace Hardware has different sizes of drill rod...