heat exchanger questions

I'm going to have my heat exchangers tested to find out if anything is either blocked or leaking. I have 2 questions:

1. My engines are Ford American Diesels, but there is a Volvo Marine shop nearby that says they can do the pressure testing. Should I take them there, or should I take them to a radiator shop, or does it really not make any difference?
2. If it turns out there are leaks, do I try to fix the thing, or throw it away and buy another one?

I would bring them to a radiator shop that doe boat work and ask them if they have the fittings to pressure test. They will have the tanks to clean them while the Volvo dealer would probably not have the cleaning tanks.


When al done I would want to see the insides myself to be certain that the tubes are fully cleaned. Old zincs and shells are hard to remove with the modern stuff they are allowed to use.


Those coolers are usually not cheap.




OTOH you can make plugs with parts from hardware store, add scrader valve and test yourself with a tire pump. Then open them up and decide if they need to go to a shop.

A radiator shop whether they do boat work or not should be able to test the exchanger. But you can do it yourself. Rent a cooling system radiator test kit from your local hardware store. Make sure it is one with a variety of pipe plug type adapters. You might have to buy at least one from a hardware store to plug the other end.

Then pressure up one side or the other to 15 psi. Usually the tube or raw water side works best. See if it will hold pressure for 15 minutes. If ok then clean by removing an end cap, rodding the tubes to make sure they are open and then fill with Rydlime or Barnacle Buster. Let sit for several hours, flush and test again.

David

seattleboatguy said:

I'm going to have my heat exchangers tested to find out if anything is either blocked or leaking. I have 2 questions:

1. My engines are Ford American Diesels, but there is a Volvo Marine shop nearby that says they can do the pressure testing. Should I take them there, or should I take them to a radiator shop, or does it really not make any difference?
2. If it turns out there are leaks, do I try to fix the thing, or throw it away and buy another one?

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I'd replace over repairing. We just replaced the heat exchanger on our FL SP135 for less than $500 (CuNi and made by SeaKamp Engineering Bellingham)

If Sen-Dure coolers, get the pressure tester and test them in place while system is still assembled. You can take the end caps off on the sea water side and look for leaks. If no leaks, take it apart and send out the coolers to get cleaned. Do the gear and oil coolers too, those foul up too. Have the radiator shop test all after cleaning.

Unless there are indications of them leaking now, I would flush them on the engine yourself.

Ya I would just flush on engine have used meratic. Acid let it sit in raw water side about 5 min then flush out with engine tuning at high rpm. That has all way cooled me down. To normal levels

I'd flush 'em first with Barnacle Buster. Did wonders for mine. My port temp went from 195F to 165F. An easy and inexpensive first step.

FlyWright said:

I'd flush 'em first with Barnacle Buster. Did wonders for mine. My port temp went from 195F to 165F. An easy and inexpensive first step.

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????

Can do this in an afternoon. Could fix your problem. So easy even I was able to do it. ?

Even if you use diluted muriatic acid don't just let it sit. Circulate it through the system.

With something like Barnacle Buster you should circulate it for at least a couple hours. With muriatic acid 30 minutes or so depending on the strength of the solution you mix up.

According to their MSDS, Barnacle Buster is 45 - 85% phosphoric acid. I wouldn't let it hang about in the engine for long and it might be a whole lot cheaper just to buy some acid at a masonry shop.

I have a cooler off a Lehman, my spare, to sell if anyone wants it. I think it was a transmission cooler. I have it on Craigslist but I haven't put it on here, it's in very good clean condition. PM me if interested.

Xsbank said:

According to their MSDS, Barnacle Buster is 45 - 85% phosphoric acid. I wouldn't let it hang about in the engine for long and it might be a whole lot cheaper just to buy some acid at a masonry shop.

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BB is safe to flush for hours. Even over night.

"Barnacle Buster ® is a safe, non-toxic and biodegradable marine growth remover specifically formulated to meet an industry wide need for fast, safe, cost effective alternatives to mechanical cleaning of seawater cooled equipment. With minimal dismantling required, Barnacle Buster ® can be safely re-circulated through seawater cooling systems, dissolving barnacles, zebra mussels, calcium, rust, lime & all other mineral deposits. Most applications can be completed within 4 hours!"

And yes you can save money by mixing up your own acid mixture.

https://en.wikipedia.org/wiki/Hydrochloric_acid

Hydrochloric Acid... The source of Muriatic Acid

Highly corrosive to most metals. Not recommended in strong non-diluted or even sightly diluted doses to anything. Mixes readily with water. 5 to 1 water to acid solution will do a lot to create surface corrosion "flake-offs on most metals... therefor forcing the release of detrimental surface build ups.

Be careful that too strong a mix of Muriatic Acid is not left in contact with metals for too long... or else... holes through the metals may soon appear. And, that can become a real bummer!

IF youm are not big on chemicals and your heat exchanger does not leak it can be hand cleaned.

A wire or dowel with a point will usually serve , it just takes some time ., and a bit of water to flush as you loosen the gunk.

On larger boats a gun cleaning brush will do a great job once its open enough to pass the brush.

All depends. When I did mine, I'd swear they had not been done before. I pulled an end cap and only saw about 3 tubes open. Don't even know how it cooled, but we had just gone all the way to desolation and back. As bad as they were, I pulled the entire HEs, took them Home to the shop and hand cleaned everything. The tube bundle came out and I custom fitted some pvc to allow me to acid flush them. Alternated the acid bath with agitation from a brush from a rifle kit. Took a couple iterations, but they finally came clean. Would not have wanted to do the heavy cleaning on the boat. No way. Plus, good ventilation is a must, also a respirator. Did an end cap inspection about two years later and they only had minor fouling.


The flushes can and do work for most, but if yours are heavily fouled like mine were, you won't get enough out. I'm a big fan of pulling an end cap and taking a good look see. Also, my original end caps were pretty much gone inside, so the inspection caused me to identify and replace everything that was needed.

Now that I have a known condition, an occasional flush works just fine.

I'm a fan of zeroing out systems on a periodic basis.

Just to be clear when we speak of circulating the Barnacle Buster through the engine is the system to use something like a five gallon bucket for both the intake and output of the engine cooling system?

Bay Pelican said:

Just to be clear when we speak of circulating the Barnacle Buster through the engine is the system to use something like a five gallon bucket for both the intake and output of the engine cooling system?

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Yes. A bucket, some hose, fittings and a pump. Bilge or a submersible A/C raw water pump work just fine.

There are lots of places that are hard to drain , esp if flushing a few tines.

A shop vac BLOWING can usually empty as well as pulling a bunch of drain plugs, and is way easier!

Many antiques have a 3-5 PSI pressure cap about what a shop vac can do with no harm.