Cleaning heat exchanger tubes

[Nomad Willy]

Salt corrosion in the tubes of the heat exchanger limit the effectiveness of the unit. When my temp got up to 240 degrees I knew I had a problem. It has always run on the warm side at an indicated 200 to 205 degrees. I found the thermostat was a 180. I had assumed it was 190 or even 200. I think my gauge is not accurate. My heat gun said the top of the thermostat housing was 184 degrees when the engine was stabilized. The engine was at 1400 rpm in gear at the dock/float.

The last time I cleaned them I used a wood dowel. Cooling-wise the engine was better controled and more stable after.

This time I first “rodded” the tubes out w a 1/8ths inch threaded rod. Was not big enough and not effective enough. The tubes are 3/16” ID. Remember 37hp engine. I have found high carbon drill rod (I think that’s what the guy at Tacoma Screw said) that’s only 1/64ths” less than 3/16”. So I think I’ve got a large enough ram to get most all the hard corrosion out.

OK what do you guys do? Or how is it done in a shop?

 

[RT Firefly]

Greetings,
Mr. mb. Personally, I would not use solid metal. A wire brush or wooden dowel perhaps. My "go to" method has been chemical cleaning which has cleaned to my satisfaction.

 

[Tootles]

Interesting what chemical is safe to use? Jim

 

[Lou_tribal]

Up here we use white vinegar to clean up car carpet full of salt crust in winter as it dissolves salt almost immediately, would soaking the exchanger in white vinegar overnight be something that would work? Just asking as stupid the question could seem

L

 

[RT Firefly]

Greetings,
There are a wide variety of chemicals and methods to be had. I strongly suspect this topic has been discussed on TF several times but where to look? I haven't a clue. Maybe one of the mods or another member can point you/us in the right direction. I've used dilute Muriatic acid when I had the exchangers off the last time as well as a product called "Salt Away" I think. I've never "rodded" the tubes.

Edit: Just took a quick search for "cleaning heat exchanger" here on TF and a number of threads popped up. MUCH better advice than I can offer.

 

[HeyJude]

Deleted Phosphoric purchased at HD in paint dept. I’ve been told that this is the active ingredient in Barnicle Buster & safer than mutatic.

 

[Nomad Willy]

RTF wrote;
“I would not use solid metal”
I was hesitalt about that too .. but .. I don’t know if the heat exchanger tubes/metal are coated w anything that could be scratched off and promote fast salting down the road. But the end I plan to cut off at an angle so it can act a bit like a drill. And this is very hard steel. Ideally I’d find some brass. But the rod itself is very smooth. Do you know how hard the tubes are or what metal they’re made of?

I’ve tried a wire bottle brush but it was big enough to smash down the brass looking wires thus making them useless.
One nice thing about a wood dowel is that a 3/16” dowel could be quickly sanded down to fit well.
But unless I use a drill there will be no path for the materal loosened or cut to exit. That’s a plus as I’ll have to use a hose w a nozzel to flush out the salted material many times ... water water everywhere.

I don’t want to remove the heat exchanger as I’ll need to cut off and replace four large and long hoses. And who likes more work?

 

[Opu]

Maybe a rifle cleaning rod with a bronze brush end fitting? They come in various sizes to fit different calibers....

 

[Simi 60]

Salt water pool filter cleaner is diluted phosphoric at close enough to the same dilution as one of the expensive marine cleaners.

I have plastic rods as well

 

[George Harmon]

Its my understanding that the tube bundle should be removed so the outside of the tube bundle can be descaled and cleaned as well.

 

[Tom.B]

Cleaning of heat exchanger tubes

We cleaned ours last summer. I did two things. Since ours was the turbo intercooler, it had soot on the outside of the tubes. I soaked it in Purple Power for a couple of days, rinsed, and then went to WalMart’s canning section and got a couple of little containers of citric acid granules. It shined them up like a new penny.

 

[Russell Clifton]

Cleaning it with chemicals would be the preferred method. You can damage the tubes by running a rod down thru them. There are two products that are popular. One is Barnacle Buster and the other is Rydlyme. Barnacle Buster is easier to find. Here is a link to their web site.

http://https://trac-online.com/product/barnacle-buster-%C2%AE-concentrate

I used a 5 gallon bucket and a small bilge pump along with some hose to make connections to the inlet and outlet of the heat exchanger's to circulate the product thru the system ( my Lehman's have 3 exchanger's ) . Instructions will be on the bottle or watch the video's on their web site.

 

[jleonard]

Maybe a rifle cleaning rod with a bronze brush end fitting? They come in various sizes to fit different calibers....

That's what I have used in the past. Then a quick drizzle thru with muriatic acid and a flush.

 

[Lepke]

I use Rydlyme because it's biodegradable and when I'm done it can be dumped over the side.

 

[Nomad Willy]

Not being a gun guy I didn’t think of rifle cleaning.
What is the rod made of?
Wonder if I’d need two sizes?

Rydlyme sounds really good. Sounds like they recomend running it through the whole seawater system. Hmmmm .. and “dumping into the sea”.

I’ll go to the gun store and check the rifle bore cleaners. Find some Rydlyme and do the 5gal bucket thing. Sounds like I wouldn’t need the gun brushes though ..? I could get wood doweling and pass it through the flues to check if all the corrosion is gone. But the wood will swell. Don’t want it stuck in the flue.
Better get down there and cut off the hoses and remove the heat exchanger. Drain the engine coolant ect. This is turning into a biggish job. UGH! And I just changed the coolant.

jleonard,
Why did you use the muriatic acid? How did you perform the “quick drizzle through”? My heat exchanger is horizontal .. intsalled.

Russell C,
No mechanical ... just circulate the “stuff”?

Tom B,
How can soot get into the coolant?

George H,
Don’t even know if that’s possible. And the outside has seen nothing but coolant.

As to the steel rod damaging the flues .. how exactly would that happen? Are the flues coppernickle steel?

 

[kchace]

I used Barnacle Buster with the "small bilge pump in a 5 gallon bucket method" and it worked extremely well. Turn it on, come back in a hour - done.

 

[MacDuff]

Barnacle Buster did the trick for me. They recommend recirculating it through the system with a pump and reservoir. I just let it sit overnight and ran the engine for 20 minutes after. Amazing what comes out. Supposedly biodegradable.

 

[Russell Clifton]

Should not need to remove the heat exchanger to do this. Just need to figure out how to remove a hose going into one end and connect it to the hose from your solution and then remove a hose at the other end and let that drain back into the bucket so the solution is circulated. You may need to use some imagination to come up with some adapters.

If you are going to go to the trouble to remove it just take it to a radiator shop and have it cleaned.

 

[OldDan1943]

The only reason for rodding a heat exchanger is that you are a great distance from a radiator shop. They can 'boil it out' with their magic potion.

I had my keel cooler of my N46 boiled out twice.

 

[jleonard]

[QUOTENot being a gun guy I didn’t think of rifle cleaning.
What is the rod made of?
Wonder if I’d need two sizes?
][/QUOTE]

Rods are usually aluminum, some are brass.
Start with a .22 brush, then go to whatever your tube ID is.

 

[Nomad Willy]

Thanks again all.

Tube dia is 3/16". I rodded it out to 1/8 dia w a pice of threaded rod.

Radiator shop? Are there still radiator shops? Guess I thought they just replaced them these days. I'll check that out. If I can get the big hoses off w/o cutting them taking it to a shop is the answer .. foe me .. I think. That spells out my day.

 

[OldDan1943]

Thanks again all.

Tube dia is 3/16". I rodded it out to 1/8 dia w a pice of threaded rod.

Radiator shop? Are there still radiator shops? Guess I thought they just replaced them these days. I'll check that out. If I can get the big hoses off w/o cutting them taking it to a shop is the answer .. foe me .. I think. That spells out my day.

Nomad Willy, finding a radiator shop can be a challenge except in areas that cater to the 'boating world'.

 

[Nomad Willy]

Thanks for the bad news Dan.
I'll take a look though.

 

[DavidM]

I wrote an article about acid flushing and uploaded it to the Library/Miscellaneous section last year. I am a retired chemical engineer who spent his early career working for an industrial chemical cleaning contractor. So I know a thing about heat exchangers, fouling, acids and cleaning techniques. I also have acid cleaned my Yanmar 6LY successfully.

Here is the link: Trawler Forum - Library - Acid Flushing Your Engine

David

 

[George Harmon]

I wrote an article about acid flushing and uploaded it to the Library/Miscellaneous section last year. I am a retired chemical engineer who spent his early career working for an industrial chemical cleaning contractor. So I know a thing about heat exchangers, fouling, acids and cleaning techniques. I also have acid cleaned my Yanmar 6LY successfully.

Here is the link: Trawler Forum - Library - Acid Flushing Your Engine

David

That's an excellent article David. I am providing another link for those that do a lot of their own maintenance. There are articles on several topics and I'm sure you are aware of Mainesail's website
https://marinehowto.com/westerbeke-universal-marine-heat-exchanger-cleaning/

 

[Tom.B]

Tom B,
How can soot get into the coolant?

Perhaps you missed the part where I said that I was cleaning the turbo intercooler and not a heat exchanger... however... they are made of the same material. And while you could skip the Purple Power, the citric acid was your takeaway. Cheap and effective :-D

 

[Simi 60]

If you download the msds for both you will see barnacle buster is diluted phosphoric acid at an overinflated price.
Saltwater swimming pool filter cleaner is also phosphoric acid at a similar dilution but far cheaper.

Rydlyme is diluted muriatic/hydrochloric acid at an overinflated price.
Brick and concrete cleaner is also hydrochloric acid but far cheaper.

 

[mramoo]

Eric, there are 5 Radiator shops in Everett.

 

[ctjstr]

Thanks for the bad news Dan.
I'll take a look though.

If nothing local for you, Northwest Radiator Works in Tacoma will do it.

 

[Nomad Willy]

It’s 2:30pm. I’m taking a break at Starbucks. The heat exchanger is out.

The hoses weren’t as bad as I thought they’d be. Only one of the four gave me any serious trouble. And I’m sure I didn’t damage any of them. Didn’t leak over a cup full of AF. All and all it went very well.

Guys I think there’s several rad shops here in MtVernon/Burlington. I’ll pop in on my favorite auto shop and find out what shop is the best.

They have us on alert for moving boats around re dredging. Hope I get it back together before they call me.

Going to fill the engine very carefully this time and avoid air pockets. I’ll use the air bleed screw on the thermostat to avoid air there. I think my jump to 240 degrees came from having an air pocket there. I have a new thermostat but I’ll see if the old one works perfectly .. as it always had before. If not .. in w the new.

I’m glad a lot of interesting stuff came out of my posting the question. Thanks for all.