IN-Place Heat Exchanger cleaning

[MikeP]

Sounds like it's WAAAY overdue for cleaning!

Seriously, the choice of the acid is pretty much about speed. Using the DD-recommended mix of Muriatic/Oxcalic acid will clean an HE to brand new condition in 5 minutes. But you have to remove the HE to do that, which I have always done until this first attempt at in-place cleaning.

Vinegar takes longer than stronger acids but the reason I tried it, (and inspected one of the HE's during and after the process) was to see how well it would work. I didn't see the time needed as an issue because the process can go on while you are doing something else - including just sitting/watching TV. But certainly, if you were doing HE cleaning for customer boats, 6 hours to do the job would be unacceptable.

 

[34Hatt]

Sounds like it's WAAAY overdue for cleaning!

Seriously, the choice of the acid is pretty much about speed. Using the DD-recommended mix of Muriatic/Oxcalic acid will clean an HE to brand new condition in 5 minutes. But you have to remove the HE to do that, which I have always done until this first attempt at in-place cleaning.

Why would you have to remove it no difference and time depends on your mix less muriatic = more time since it would never be straight.

 

[bobk]

Why would you have to remove it no difference and time depends on your mix less muriatic = more time since it would never be straight.

The DD way is a dunk in muriatic off the boat. If you were to pump it around as is done in the in-place method, you would have acid fumes all through the ER and that WILL lead to corrosion of all sorts of things.

Bobk

 

[MikeP]

Exactly right. I would not attempt to run the DD mix "in place."

 

[34Hatt]

How about turn on your blowers and put a cover on the pail ?

 

[SEVEN]

Nice thing about using vinager over acid is you can pour the vinager overboard without harming anything after the flush. Or just pour it into the toilets to help in the holding tanks.

 

[bobk]

How about turn on your blowers and put a cover on the pail ?

I would not run that risk. Accidents happen, fumes will escape. Phosphoric acid is cheap and non-volatile. Why not use that?

Bobk

 

[34Hatt]

I would not run that risk. Accidents happen, fumes will escape. Phosphoric acid is cheap and non-volatile. Why not use that?

Bobk

Just because I have the muratic and was thinking of a dilution of 70% but I think I will just get some Phosphoric.

So if I get Phosphoric and some Oxalic what would you make the mix ratio's?

 

[bobk]

Just because I have the muratic and was thinking of a dilution of 70% but I think I will just get some Phosphoric.

So if I get Phosphoric and some Oxalic what would you make the mix ratio's?

1/2 gal phosphoric acid, 2 1/2 gallon water, 2-3 ounces of oxalic acid. Always pour the acid into the water to avoid splatter.

Bobk

 

[MikeP]

Or just use vinegar!

 

[34Hatt]

Or just use vinegar!

I am not retired like some


Thanks Bob will give that blend a try.

 

[MikeP]

Yes, being retired makes the 6 hours a non-issue. But in my defense, I have to say that I DID spend the time that the vinegar was being circulated doing other work on the boat!

One thing worth considering re in-place cleaning that, as far as I am aware, has not been discussed and it's the reason I am against doing it as the "first" cleaning of the HEs on your watch.

In-place cleaning only addresses 1/2 of the HE's passages. Comparing it to a car radiator, in-place cleaning is like cleaning a car radiator by shooting a water jet from a hose through the fins - there would be no cleaning whatsoever of the internal cooling passages. That's exactly what happens with in-place cleaning - no cleaning of the internal (coolant -side) passages of the HE.

That is the reason that, up to the most recent cleaning, I have always pulled the HEs and dipped them in the Muriatic/oxalic/water mix that DD recommends. I was pleased with the in-place cleaning results but I still will pull the HEs/dunk them every other cleaning.

Now, one can argue that with proper coolant/water mix, there should be little/no scale internally. But it seems to me that we should start with a known, not an unknown. IOW, unless you have owned the boat since new, you probably have no idea of what the PO did in this regard, and therefore, no idea of the condition of the HE.

 

[LARRY VALENTINE]

As many of you know, I have never been a fan of in-place HE cleaning, preferring to pull the HEs and boil them per DD. However, I would like to try the in-place. Im looking at the plumbing, trying to see the most effective way to do this as far as "tapping into" the RW cooling system. I want to be able to flush opposite to the normal flow and to flush through the HE and then the fuel cooler and then the intercooler. Does anyone that uses the in-place method have a good description or pics of what they do?

Since we just did a WOT run yesterday, doing the in place would give me a great opportunity to see how it works re cleaning. I know that boiling the HE/intercooler per DD will allow the boat to run at WOT for extended periods with no coolant temperature issues. And I know that at present, the HE condition will NOT allow that. So this would be a perfect opportunity to try it out and evaluate.

My diesel mechanic just finished cleaning my port Heat exchanger which looked much worse than
the picture presented in one of these threads. The bill was as follows: cleaned heat exchanger plates and
small parts-$240; cleaned HE and tested-$350; installed HE and core $320; Seals for HE-$15.08; gland for HE-$12.87; HE gaskets- $14.25. Every thing looked brand new,but look how much money you saved.

 

[saltshaker]

A friend of mine just spent $1200 having his Cummins 6CTAs cleaned in place by a guy who just does this. He did the same thing as done here. Took 3 hours to do and he left a nice stain on the deck in his cockpit.