Heat exchangers

[Bretto77]

Anyone had any experience with descaling tubular heat exchangers? Gearbox heat exchangers on two C32's. I think phosphoric acid or even just vinegar, but a lot of the boys reckon caustic solutions.

They are brass. 

[Angry51]

No!!!!!!

[Bretto77]

1 minute ago, Angry51 said:

No!!!!!!

Is that a No don't do it? Or No experience?

[Angry51]

No, know nothing.

 

We used to have really bad bore water and Ann used hydrochloric acid to clean scale

off pipes. But, really can't help.

[Bretto77]

Ok. They actually appear to have a nickel content too. Hydrochloric acid will rip the zinc from the outer surfaces quickly. I don't like these problems much.

[mangajack]

Brass and caustic soda are not friends at all.....have you thought about abrasive flushing them?

 

[Bretto77]

So I had a funny dealing (or at least I thought so anyway), with Hastings the other day. Chasing options on refurb kits for the water pump (connected to mentioned heat exchangers), and I got "None in the world" as a reply. I said "OK not available". The dude on the other end of the phone got grumpy with me and said " NO they ARE available, there's just none in the world".... Go figure...

[Bretto77]

13 minutes ago, mangajack said:

Brass and caustic soda are not friends at all.....have you thought about abrasive flushing them?

 

Yes, but just want to soften or dissolve scale without compromising material thickness. I don't like the caustic idea. They are off and out of circuit and I can dip them without having to worry about seals etc. The scale is not to clogging point. I suspect a weak acid with dips and rinses will do it. But I am certainly no expert.

[rayke1938]

Suggest you talk to someone with mercruiser experience. Michael at Coorparoo marine may be able to help his father used to do a lot of work on mercruisers.

[Bretto77]

Phosphoric acid. Sorted.

[Angry51]

Look like new bought ones.

You the man.

[Bretto77]

6 hours ago, Angry51 said:

Look like new bought ones.

You the man.

I won't be if that boat ends up bobbing under no power other than wind, wave and tide...