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Discussion Starter · #1 ·
What causes copper tuberculation?

To be clear, I'm not talking about erosion-corrosion, flux pitting or glavanic corrosion. I'm talking about that random green chickin pox looking stuff that cause pin holes. Seems like it must be something in the water as it isn't localized usually.

I think this is a toutahnow kinda question
 

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The Old (antique) Master
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What causes copper tuberculation?

To be clear, I'm not talking about erosion-corrosion, flux pitting or glavanic corrosion. I'm talking about that random green chickin pox looking stuff that cause pin holes. Seems like it must be something in the water as it isn't localized usually.

Protech ... I also talk on PDL & PIPDL on both is a 80 something year old master plumber, lives in Florida ... An expert on pinholes in copper.

Bud Hardner is his name, here is a link.

http://www.copperknight.com/
 

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Plumbing Contractor
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Are you talking about something like this:





Those are from my ongoing slab leak project. We have finally scheduled the home re-pipe job.

This is not from flux, it is a water issue..

I got the report from Mueller, will try to post it later.
 

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Sounds like Florida need to ban copper all together and go all pex.
 
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No Longer at This Address
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The short answer is all of the above. The tubercles are the result of corrosion but it could be one of a million things related to the water. In my valley in is for the most part dissolved gasses. The funny part is it only seems to be the annealed copper that fails. The only way you will every know with any certainty what the mechanism of failure is would be to hire a Metallurgist and have the pipe analyzed with a Energy Dispersive X-ray (EDX) in a Scanning Electron Microscope (SME). When they examine the corrosion site any element which is not copper will be identified. If the Metallurgist cannot identify the problem you would need to hire a Chemist as well. It is not cheap to find the real answers hence all most plumbers need to know is it is a corrosion caused by the environment the pipe is in.

Mark
 
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I think a few things can cause the same problem. The soil,the water and stray current or a mix of all 3,2 or just 1. I've been to homes where the copper main was pinholed with green nodules everywhere.......only the pipe in the ground was like that....the pipe hanging under the house was in perfect condition......I say its electrolisis. Things can change too...what was doing the damage may be gone by the time I get there and find the damage. Its not the water here or we would have more of it happening.....its too random to be the water here. Here the soil is different in different parts of the city......I find more of it down toward the swampy part of the city where the ground stays wet......great for condutivity.
 

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I think a few things can cause the same problem. The soil,the water and stray current or a mix of all 3,2 or just 1. I've been to homes where the copper main was pinholed with green nodules everywhere.......only the pipe in the ground was like that....the pipe hanging under the house was in perfect condition......I say its electrolisis. Things can change too...what was doing the damage may be gone by the time I get there and find the damage. Its not the water here or we would have more of it happening.....its too random to be the water here. Here the soil is different in different parts of the city......I find more of it down toward the swampy part of the city where the ground stays wet......great for condutivity.
I also thought my customers issue is something to do with electrolysis. It seems all the under ground copper is like those pics I posted and only on the cold supply lines. All lines above slab seem to be clear or at least the bath we started to remodel on Thursday were clear. This place also had a sulfur smell on 1 lav (cold side) in the master bath in the morning for a few minutes, that disappeared since we installed a water softner and a whole house carbon filter system. The hot lines have a recir system so the water is constantly moving which seems to keep the development of corrosion to a minimum. Now I will try to figure how to post the Mueller report. The pictures really make me wonder what this does to our body..
 

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For what it's worth, I was told by one of the top specialist in the copper corrosion that electrolysis is the most over used word in copper corrosion. It's not that it doesn't happen but it usually is something other than electrolysis.

Mark
 

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Discussion Starter · #11 ·
no, not like that

Are you talking about something like this:





Those are from my ongoing slab leak project. We have finally scheduled the home re-pipe job.

This is not from flux, it is a water issue..

I got the report from Mueller, will try to post it later.
 

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Discussion Starter · #12 ·
I agree completely.

For what it's worth, I was told by one of the top specialist in the copper corrosion that electrolysis is the most over used word in copper corrosion. It's not that it doesn't happen but it usually is something other than electrolysis.

Mark
 

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I originally send this to Cerro Copper, they split the pipe open and informed me that this was a Mueller product. There is coding inside, something I did not know. Any way we resent the piece to Mueller, which they say its undetermined who's pipe it is. I will be sending a piece to Copper.org to see what they come up with. But this place will be getting a complete re-pipe

Here was the report..




Item No. Part No. Size Description Rec’vd. Qty

1 LS-04060 ½” Type L Soft copper tube 11”

Problem Description: Pinholes in copper tube installed at residence of Mr.

[ ] Mfd By Mueller: _____________ [ ] Defective Material
[ ] Not Mfd by Mueller [X] Material Not Defective
[X] Unidentified Manufacturer [ ] Insufficient Information

[ ] Improper Installation/Workmanship [ ] Damage From Shpg/Pkg
[X] Exposure to Corrosive Environment [ ] Discontinuity
[ ] Exposure to Severe Service Condition [ ] Improper Copper Chemistry
[ ] Improper Dimension [ ] Improper Annealing
[ ] Improper Marking/Identification [ ] Improper Cleanliness
[ ] Other: ________________________________

Eric:

The purpose of this letter is to report the results of Mueller Copper Tube Company’s investigation of the above product. The sample provided for investigation (Figure 1) was assigned Product Complaint Investigation No. .

The investigation confirmed a pinhole perforation in the ½” Type L soft copper tube sample that you had submitted (Figure 2). The copper tube had been manufactured properly in accordance with ASTM B88 and was not defective. The chemical composition of the copper tube was consistent with Copper Alloy No. UNS C12200 requiring 99.9 wt% minimum Copper+Silver and 0.015-0.040 wt% Phosphorus. The chemistry of the copper tube was actually 99.92 wt% Copper and 0.033 wt% Phosphorus. Because the tube had already been longitudinally split, the average outside diameter could not be measured. By fitting the two halves together, it was approximated to be 0.625”, where ASTM B88 specifies ½” Type L soft copper tube to have an average outside diameter of 0.625” ± 0.0025”. The wall thickness of the tube varied between 0.036” and 0.038”, where ASTM B88 specifies a wall thickness of 0.040” ± 0.004” for ½” Type L soft copper tubing.

The pinhole was determined by metallographic examination to be the result of localized corrosion pitting, which had been initiated along the inside diameter surface of the tube (Figure 3). Its microstructure was consistent with that of an annealed copper tube supplied in the O60 temper as specified in ASTM B88. No manufacturing or material defects were visible within the cross-sectional sample examined.


Due to the complex nature of copper corrosion, caution should be exercised when assessing a cause for corrosion of copper based upon such a limited number of samples and available data regarding the system. However, with the assistance of scanning electron microscopy and energy dispersive x-ray spectroscopy (SEM/EDS), several pertinent facts were uncovered.

First, numerous, small corrosion pitting sites were also visible along the inside diameter surface of the tube around the pinhole (Figure 4). EDS spectra collected from within these corrosion sites indicated detections of sulfur and phosphorus (Figure 5). Secondly, much of the internal, uniform scale deposits (Figure 6) also evidenced sulfur and phosphorus from EDS spectra collected (Figure 7). Finally, around the immediate periphery of the pinhole and along its sides, similar scale and corrosion deposits (Figure 8) also evidenced sulfur in the EDS spectra collected from them (Figure 9).

Sulfur and sulfur compounds have been cited in literary resources prepared by recognized authors and associations as being corrosive to copper and copper alloys. Therefore, the EDS detections of sulfur collected from the internal scale deposits, micropitting along the inside diameter surface of the copper tube, and along the sides of the pinhole itself makes it a suspected attributor to the corrosion of the copper tube. Although sulfur is not used in the manufacture of copper tube, its source could not be determined by examination of the subject tube sample. Hydrogen sulfide in certain waters and use of aluminum sulfate (alum) for reduction of turbidity are two potential sources.

Polyphosphates have been intentionally introduced to some domestic waters and are not considered corrosive to coppers. Described by the American Water Works Association, polyphosphate is, in fact, sometimes added as a corrosion inhibitor. So, the EDS detections of phosphorus are innocuous and not typically associated with corrosion of copper.

In conclusion, then, the pinhole resulted from corrosion pitting initiated along the inside diameter surface of the copper tube. Although no cause for the corrosion pitting can be conclusively identified, sulfur was detected by energy dispersive x-ray spectroscopy along the internal surface of the tube and within the corrosion pits and is reported as being corrosive to copper and copper alloys.



Respectfully,

Edd Finley
Edd Finley
Metallurgical Engineer
Mueller Copper Tube Co.
















 

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For what it's worth, I was told by one of the top specialist in the copper corrosion that electrolysis is the most over used word in copper corrosion. It's not that it doesn't happen but it usually is something other than electrolysis.

Mark
I had an electician tell me if a house has multiple ground locations that pipe in between those ground locations if the soil stays damp can attack the pipe.........he said it could even be a neighbors house's ground rod talking to your homes ground system and eating any pipe in between them. Did I mention the gound stays wet here most of the time and in some parts of town it never really dries out other than about a 12' crust. Just in jan, we have received about 12" of rain.....we got 2-2.5" yesterday.
ADD> The homes I'm talking about are about 15-20' apart at most....some closer and are approx.65 years old. Some homes you see the problem and some you dont.
 

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Discussion Starter · #15 ·
Thank you for sharing your test data. I do have one question. What direction was the jet from spraying? Up, down, horizontal?

I originally send this to Cerro Copper, they split the pipe open and informed me that this was a Mueller product. There is coding inside, something I did not know. Any way we resent the piece to Mueller, which they say its undetermined who's pipe it is. I will be sending a piece to Copper.org to see what they come up with. But this place will be getting a complete re-pipe

Here was the report..
 

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٩(͡๏̯͡๏)۶&#
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Discussion Starter · #16 ·
I've never seen a confirmed case with AC grounding. DC is a whole nother ball game though.

I had an electician tell me if a house has multiple ground locations that pipe in between those ground locations if the soil stays damp can attack the pipe.........he said it could even be a neighbors house's ground rod talking to your homes ground system and eating any pipe in between them. Did I mention the gound stays wet here most of the time and in some parts of town it never really dries out other than about a 12' crust. Just in jan, we have received about 12" of rain.....we got 2-2.5" yesterday.
 

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Thank you for sharing your test data. I do have one question. What direction was the jet from spraying? Up, down, horizontal?
If you are talking about the pinhole in the line, all of them (7) so far have been at the top of the tubing spraying towards the slab. The water does do a nice polish job on the concrete.
 

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I've never seen a confirmed case with AC grounding. DC is a whole nother ball game though.
I tell ya what got our thinking it was electrolysis is when you'd cut the copper through the pinhole you would either get a tingle or an all out arc from pipe to pipe when the pipe cut. The pipe would have holes or the beginning of a hole every few feet or all over it...random. It would also be very brittle and thin throughout the entire pipe. Also somtimes we wouldn't get any tingle or shock at 1st...but if the offending appliance turned on while you had the pipes apart and then touched them you would get a shock....we narrowed it down once to a freezer once...it was the oldest appliance in the house and when it kicked on you would get trickle of voltage down the pipe...it cuts off and it would stop.
Theres no telling how many pinholes i repaired due to electrolysis and the offending appliance or condition had long since been corrected or removed.
 

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ESP what does all that testing cost...Just a round about price off the top of your head? I have no idea.
 
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