Dwight, Very logical method. I may try that too. Chuck
----- Original Message ----- From: "dwight veinot via CnC-List" <cnc-list@cnc-list.com> To: cnc-list@cnc-list.com Cc: "dwight" <dwight...@gmail.com> Sent: Tuesday, August 11, 2015 8:34:44 PM Subject: Re: Stus-List cleaning heat exchanger I just wanted to give an update on cleaning the salt water side of the heat exchanger on my Universal M4-30. I took the easy way out and used chemicals and increased the rate of salt water exiting the exhaust from around 1 gallon per minute before cleaning to over 3 gallons per minute after cleaning at idle (1000 rpm). Here is a summary of what I did. I disconnected the inlet hose to the salt water pump and tied it off high above the waterline so I did not have to close the hull valve which is not located in the easiest of places to reach on Alianna. I removed the pencil zinc from the heat exchanger and inserted a blank plug. I bought 4L of concentrated (31.45%) muriatic acid (same as hydrochloric acid) for about $10 from the local hardware store and I diluted 2L of that concentrated acid 1 acid to 5 fresh water in a 3 gallon plastic bucket...it is important to always add acid to water (just like the alphabet goes A to W) and also to have a ready supply of water to flush if you accidentally get some on your skin or in your eyes and also be careful not to inhale fumes when you open the concentrate container. My first degree was Hons Chem and I had many years of advising Dockyard staff in the chemical cleaning facility for the Canadian Navy so I have a fair knowledge of chemicals and their interaction with metals and their safe use. So I ran the engine up with a section of hose from the salt water pump into the bucket of acid mix and introduced about a gallon of the mix into the heat exchanger and then stopped the engine. Let that soak for 10 minutes and then started the engine again and introduced a second gallon of acid mix, stopped the engine and let that soak for 10 minutes. When the first batch exited the exhaust it was a dirty rust yellow color and the flow exiting the exhaust already appeared much increased. Then after 10 minutes soaking with the second batch I started the engine and introduced a third gallon of acid mix, stopped the engine and let that soak for 5 more minutes. The effluent from the exhaust got cleaner after the second and third soaks and after 3 soaks it had no visible color. Then I reconnected the hose for saltwater intake to the pump and ran the engine on idle for about an hour. while I measured more accurately the water flow out the exhaust which was over 3 times the rate before the cleaning at over 3 gallons per minute on idle. I suppose the real test will come when I steam into my first head wind and want the engine running at 3000 rpm or better for more power but for now I feel quite assured that my over heat issue has been addressed. I will replace the pencil zinc later but I must say it does not get wasted that quickly since it has been insatlled for nearly 2 seasons now and still seems to be quite intact so I guess it would do 3 seasons at least. Anyway this process took about an hour, plus the celebration time while the engine was running on idle after the cleaning and all seems well. My thought is that acid cleaning is a lot easier and probably more effective than mechanical cleaning with wooden dowels or wires. I will now do this procedure (probably only one soaking) on a more regular basis because I really think it did an excellent job. I believe phosphoric acid might also do a good cleaning but it was not readily availbale without going to the big city. I am a happy sailor tonight. Thanks to eveyone for the helpful input, especially that video on Rydlyme from Chuck which Robert drew to my attention. Dwight Veinot C&C 35 MKII, Alianna Head of St. Margaret's Bay, NS d.ve...@bellaliant.net On Sun, Aug 9, 2015 at 8:52 PM, dwight veinot < dwight...@gmail.com > wrote: Rick, how did replacing the pressure cap on the fresh water side solve your problem. I have never checked the thermostat but the hose clamps do not appear to be leaking...there is an overflow drain right below the pressure cap. Dwight Veinot C&C 35 MKII, Alianna Head of St. Margaret's Bay, NS d.ve...@bellaliant.net On Sun, Aug 9, 2015 at 12:30 PM, Rick Brass via CnC-List < cnc-list@cnc-list.com > wrote: <blockquote> Dwight, I have an M35B (which is a newer engine but appears similar to the M4-30) in Imzadi, and my process for cleaning the heat exchanger is slightly different than Chuck’s but accomplishes the same thing. My heat exchanger is athwart the aft end of the engine. Access to the heat exchanger is only practical through the cockpit locker on the starboard side. Both cleaning the exchanger and changing the pencil zinc are done from down in that locker. The end cap of the exchanger on the port side of the boat is almost impossible without major surgery because of the quarter berth. Shut off the raw water seacock. Remove the end cap and seal to open up the chamber that includes the zinc and access to the cooling tubes for the raw water. As with Chuck’s exchanger there are something like 30 tubes that run through the body of the exchanger that holds the fresh water. You will lose a gallon or two of raw water into the bilge, but you are not opening up the fresh water side of the system at all. I use a rod and stiff wire brush, that I bought at the local sporting goods store for about $20US, that is made for cleaning the barrel of a .22 caliber rifle. The brush will clean the scale from inside the tubes very well. I have also pushed a couple of chunks of corroded zinc out of the tubes when I went more than a year without changing the pencil zinc and the zinc was really used up. Push the rod and brush through each tube and then pull it back out. Reassemble the end cap, turn on the seacock, and you are good to go. The hardest part is cleaning and repacking the locker and climbing in an out. I personally think every boat should come with its own midget, or with a precocious 12 year old that has a mechanical engineering degree. My boat normally runs about 165-170 degrees, and will get to 185 or so if I push it at hull speed for a while. Two years ago I had experience with it climbing above 200 (which is why I got the tool for cleaning the heat exchanger) but the final solution to the problem was replacing the pressure cap on the fresh water side of the engine. Be sure to check out the cap, thermostat, and hose clamps on the fresh water side if you have not done so already. At the recommendation of my friend, who is a diesel mechanic and helped with my repower 5 years ago, I change the zinc yearly and clean the exchanger every two or three years. He recommended doing it every other year if sailing in salt water to avoid salt buildup. He indicated there is really no need to clean the fresh water side of the heat exchanger if you keep proper coolant in the engine. Because there have been so many stories on the list about plugged exhaust elbows on Yanmar engines, I asked about the need for cleaning the exhaust riser on my Universal. He said the Universal/Westerbeke/Beta engines are quite different than the elbows on the Yanmars, and very seldom have problems. On the Yanmar 2GMF in his J/30, OTOH, removing the elbow and cleaning it out is part of annual maintenance. Rick Brass Washington, NC From: CnC-List [mailto: cnc-list-boun...@cnc-list.com ] On Behalf Of Chuck S via CnC-List Sent: Sunday, August 09, 2015 9:35 AM To: CNC boat owners, cnc-list < cnc-list@cnc-list.com > Cc: Chuck S < cscheaf...@comcast.net > Subject: Re: Stus-List cleaning heat exchanger Hi Dwight, I do have the M4-30 and it when it ran hotter than normal, I clean the little tubes with 1/8" wooden rods I buy from an art supply or hardware store. I run my engine at 190 degrees. I thottle back if the temperature gets above that. To clean: With the engine off and the seacock shut, I remove both ends of the exchanger and simply push the wooden dowels through a few times. There are about 30 to 40 tubes, but it's pretty easy. A diesel mechanic recommended I remove the exchanger and have it acid cleaned to remove any scale from the fresh water side. I haven't done that. I heard of a product you use without disassembly, and then you flush it and replace your water and antifreeze mix. I'll try and find that. Chuck From: "dwight veinot via CnC-List" < cnc-list@cnc-list.com > To: cnc-list@cnc-list.com Cc: "dwight" < dwight...@gmail.com > Sent: Sunday, August 9, 2015 8:20:01 AM Subject: Re: Stus-List Raymarine EV-100 and backbone wiring Hi Chuck I recall reading in one of your C&C posts that you have an M4-30 and that you dismantled and cleaned the heat exchanger. Is that correct and if so what did you find inside? I mean how it’s built and was anything clogging it? Also did you ever do any cleaning/maintenance where the salt water from the heat exchanger enters the exhuast gas line? My M4-30 runs great at 1600 rpm but when I run it at higher rpm’s it runs hotter than I think it should, like at 2500 rpm the temp gage climbs to boiling and sometimes 220 F but the engine is still smooth and strong, just hotter than I would like to see. I would like to see more water exiting the boat and I know my raw water pump is good since I have installed a new impeller with no noticeable change in performance and I know the raw water feed to that pump is not blocked, lots of flow into the bilge when I disconnect it from the pump. Can yo give me any advice from your experience. Thanks dwight Dwight Veinot C&C 35 MKII, Alianna Head of St. Margaret's Bay, NS d.ve...@bellaliant.net _______________________________________________ Email address: CnC-List@cnc-list.com To change your list preferences, including unsubscribing -- go to the bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com </blockquote> _______________________________________________ Email address: CnC-List@cnc-list.com To change your list preferences, including unsubscribing -- go to the bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com
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