Just how critical is it to wipe the flux off copper pipes?

[Brandon1023]

Well it finally dawned on me after doing more than a handful of copper pipe work over the years. I've always seen the little green streaks on previous plumbing jobs when I'd open the walls up and whatnot and never really thought about it until today when I was working in a rental property and I'll attach a pic of the shower diverter I changed out. It had to be in there for probably 30 years but you could tell they used a ton of flux when they installed it. In my own home I've seen the green run marks on pipes that are almost 20 years old and they don't leak sooo..

Are all the projects I've done considered doomed? I can't exactly go back and wipe it off as many of the pipes are enclosed in shower walls. I've read up on it tonight and the consensus seems to be that the flux will slowly corrode the copper over the years and cause pinhole leaks. Unfortunately I feel like it's going to always be in the back of my mind now because I never got in the habit of wiping the flux off with a wet rag.

I should also mention that I don't go crazy with flux. I wipe a thin layer on the pipe and the inside of the joints. The flux in the joints should get washed away when the water runs I would think.

I'd love to hear some opinions cuz I'm silently worrying deeply haha. I can't find the emoji of hitting the head against the wall so this will have to do.

 

[Twowaxhack]

There’s is a lot of info on this from flux manufacturers.

Follow their directions.