Dezincification?

[AJ3]

This house was built in 2009. Is this dezincification?
Thanks for any input.

 

[Dana]

If the brass is starting to turn more of a coppery red than yellow, probably yes.

 

[Sponsor]

 

[hj]

Dezincification, causes white "warts" on the brass.

 

[Dana]

Dezincification, causes white "warts" on the brass.

Any white corrosion (wart-like or otherwise) is suspect. The reddish hue of the brass and the copious amount of white crud a the transition to the PEX is suspect, the more yellow-brownish stuff less so, but may be a mixture of zinc/other:

 

[WorthFlorida]

I'm curious, do you have well water or city water? If city water is it lake/reservoir water or groundwater? If you have city water there should be an analysis report (usually on line) of your water chemical tests. I'd be worry about any fittings behind the walls? If you have chlorine (pool chlorine or bleach) stored nearby, the chlorine gas will cause corrosion.

Found this on a google search. Leaching of zinc. The most common example is selective leaching of zinc from brass alloys containing more than 15% zinc (dezincification) in the presence of oxygen and moisture, e.g. from brass taps in chlorine-containing water. ... Dezincification can be caused by water containing sulfur, carbon dioxide, and oxygen. It only happens on brass, not copper.

However, this looks like residue from the sweat joint. It is on the copper only and not the brass fitting. It seems to only be where the solder is and where solder flux may have run when it was heated and I've seen this in my own homes. Take a Brillo or SOS pad and clean it up and look for what Dana described. If it comes out nice and shiny keep an eye on it for a while. The picture Dana shows looks different and pitted but it is still copper, not brass.

 

[Dana]

Most sweat-to-PEX fittings I see on potable plumbing are low-lead brass, not copper, which is why the coppery-red hue in the picture in my prior post is suspect. If it is indeed a copper adaptor it's not clear what the white crud is, but it doesn't look related the crud at the soldered end of the fitting..

This one isn't residue from a sweat solder, but doesn't appear as red as the others, and it's the same color of whatever that crud is on the red handle of the ball valve and not so white, so probably not a zinc issue:

 

[WorthFlorida]

Looks like a little pipe dope was used. If all of these fittings are in a garage, chemicals stored in the garage, gas cans and other petro chemicals evaporating can easily condense and react.

 

[Dana]

The pipe dope looks like a different color than the rest of it- I could believe it was drywall joint compound. It doesn't look white enough to be zinc, but color rendering is all over the place with digital cameras under different lighting condition.