No Sweat!
September 1, 2006 2:13 PM Subscribe
Can I safely use stearic acid & rosin flux when I sweat copper pipe?
I'm learning to sweat solder copper pipe. I'm getting better at judging temperature and making cleaner joints, but on my way there, I discovered that some acid-rosin flux I had lying around for electronics work gave me better joints than the water-soluble flux they sell nowadays for plumbing.
Am I courting disaster by using acid-rosin flux on copper pipe? Or is it (as I've heard) just an environmental regulation thing: they want people to switch over to an inferior, but environmentally friendlier, substitute flux?
I'm learning to sweat solder copper pipe. I'm getting better at judging temperature and making cleaner joints, but on my way there, I discovered that some acid-rosin flux I had lying around for electronics work gave me better joints than the water-soluble flux they sell nowadays for plumbing.
Am I courting disaster by using acid-rosin flux on copper pipe? Or is it (as I've heard) just an environmental regulation thing: they want people to switch over to an inferior, but environmentally friendlier, substitute flux?
For sheer density of jargon, this has to be the best Ask MetaFilter question of the year. And you got an answer!
posted by joeclark at 4:02 PM on September 1, 2006
posted by joeclark at 4:02 PM on September 1, 2006
As I understand it, it's not an environmental thing. Acid flux is cheaper, but it causes corrosion that would be bad for electronics. Why the corrosion isn't a problem for water pipes, I don't know.
(Of course, you shouldn't use lead solder for drinking water pipes: that is an environmental/health thing.)
posted by hattifattener at 6:06 PM on September 1, 2006
(Of course, you shouldn't use lead solder for drinking water pipes: that is an environmental/health thing.)
posted by hattifattener at 6:06 PM on September 1, 2006
My dad (pipefitter, retired two years ago after about 30 - 40 years in the trade) always used acid flux on copper pipes. Also he used mostly lead based solder (yeah, not good nowadays, but I suppose old habits die hard). Considering the inside of the pipe is going to have water inside of it that will wash out the acid, and the outside of the pipe will slowly sweat away the flux, and you'll be wiping off the joint after, I suppose that's enough to clean it. But he was the pipe joiner, not me, I just solder electronics together for fun. :-)
Now, acid flux is absolute garbage for electronics, though, unless you want to spend time cleaning the heck out of your PCB afterwards. I've seen the aftereffects of it, especially on today's SMT stuff. Within a year, the board was trashed.
posted by shepd at 10:22 AM on September 2, 2006
Now, acid flux is absolute garbage for electronics, though, unless you want to spend time cleaning the heck out of your PCB afterwards. I've seen the aftereffects of it, especially on today's SMT stuff. Within a year, the board was trashed.
posted by shepd at 10:22 AM on September 2, 2006
This thread is closed to new comments.
posted by ptm at 2:45 PM on September 1, 2006