strange copper corrosion

[PaulLag]

Hi there

hope you are fine

Please, I would like to ask you some piece of advice if possible, since I am finding some results I can't explain.

Following is the topic
I have some copper fin heat exchangers - and copper tube - in costal area, having 6 years of service
Basically the area is not industrial, therefore I would consider the solution appropriate.

Nonetheless, this is what happens
- the copper fins are very soft to touch, and seem to be falling apart soon.
- the neat heat exchanger, with vinyl fins, is not corroded !



Please any thought about this ?
Basically I would expect copper to be corroded later than aluminum, and this can't be a Cl attack, since Al would corrode before copper.
May this be a S2 or N2 attack ?
Does anybody of you know any case history ?

Many thanks

 

[EdStainless]

1. pictures please, with good color
2. Do you know the actual alloys? It is critical
3. how are they installed, indoors or out, are they rained on?
Any animals in the area (birds or mice nesting overhead?)

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[PaulLag]

@ Mr Edstainless

1 -I am here attaching you available picture
2 - yes, both , tube and fins, Cu-DHP
3 - the units are outdoor, and they are likely rained on. Nonetheless, please note that these are table models. What you see is the bottom part
4 - I have seen no animals, nonetheless I can't exclude. To me, anyhow, it doesn't seem ammonia corrosion.

Many thanks

 

[EdStainless]

Is the top as bad as the bottom?
I have seen this before, but am not able to recall what it was.
I'll think of it.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[PaulLag]

@ Mr EdStainless

no, the top is closed by a fan shroud.
I can't see if the top is as bad.

It would be great you to recall

Thanks for your help

 

[bimr]

Looks like typical corrosion from an ocean environment. Probably should have some type of corrosion coating.

http://www.achrnews.com/articles/96333-the-salt-air-nemesis-and-solutions

 

[PaulLag]

Hello

many thanks to everybody who has answered to this post.
Mr bimr, I frankly beg to differ concerning the equivalence stated in the article you sent for copper fins and aluminum fins with corrosion protection..
I have seen tests in salty fog chamber where the copper fin resistance is higher than fins with aluminum and baked phenolic.
I deem that all in a all we have in one case two different materials, one less noble, while with copper fins, tube and fin present same corrosion potential.

Thanks

 

[weldstan]

PaulLag,
The article provided bimr also deals with heavy corrosion damage experienced in copper fins. It may well be that periodic washing of the fins with potable water will extend the life of newly installed copper fins or coat them and periodically wash.