Iíll bet you havenít seen this before

Old 10-04-20, 09:18 AM
Thread Starter
Join Date: Nov 2002
Location: Massachusetts
Posts: 1,731
Received 1 Upvote on 1 Post
Iíll bet you havenít seen this before

This coil was put in about 9 months ago we fix leaks weekly now both circuits, 56% flux coated rods, located in a paper recycling plant. Iím thinking it must be some kind of sulphuric compound but they claim they donít have any sulphuric... what could be eating this copper coil like this?
Old 10-04-20, 10:19 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,401
Received 4,047 Upvotes on 3,631 Posts
There is definitely something being carried in the air that is attacking/pitting the copper.
You need to find out if the processing is chlorine free.
The link below has some good information on this subject.
Coil coatings and corrosion.
Old 10-04-20, 12:58 PM
Join Date: Aug 2020
Posts: 29
Received 5 Upvotes on 3 Posts
Whatever is doing that to copper is not something I'd want to breathe.
Old 10-04-20, 01:06 PM
Join Date: Jan 2009
Location: United States
Posts: 1,059
Received 80 Upvotes on 75 Posts
Wow Yes! I agree that is a chemical I would not want anywhere near me let alone breathing any vapors.
I have never seen an HVAC coil that bad before so yes I haven't seen this before.
Old 10-04-20, 05:37 PM
Thread Starter
Join Date: Nov 2002
Location: Massachusetts
Posts: 1,731
Received 1 Upvote on 1 Post
thanks for the quick responce. I will forward the data immediately
Old 10-05-20, 04:59 AM
GregH's Avatar
Super Moderator
Join Date: Jan 2001
Location: Manitoba
Posts: 9,500
Received 68 Upvotes on 62 Posts
The return bends in a coil are a weak point in the system.
The copper starts our being thick but thins when making the bends.
My experience is that if an original coil lasted many years in this environment a new one could be a victim of cost cutting by using a less expensive material.
If the owner of this facility does not want to spring for stainless coil there is a way to extend the life of a standard one.
On a new coil, clean well then brush coat all the end bends with a two part epoxy paint.
It will not replace a SS coil but will make it last a reasonably long time.
This problem is quite common with prep coolers where acidy condiments like pickles are stored, the problem being the acid environment from the vinegar.
PJmax voted this post useful.
Old 12-04-20, 04:23 PM
Join Date: Mar 2014
Location: USA
Posts: 3
Upvotes: 0
Received 1 Upvote on 1 Post
I suspect they are using a bleaching compound that contains chlorine or hydrogen peroxide, both of which are not compatible with copper.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: