Posted on 03/14/2024 3:00:58 PM PDT by Paul R.
I never saw a bad brand of flux anywhere.
“I’ve done a lot of copper pipe soldering in the past, but that was to the outside surface of the pipe or tube, slipping into some fitting. Never had a problem with the inside surface of a fitting, if new.”
You mean you didn’t brush or sand the inner surface of the fitting? If so, it is hard to imagine you got a proper joint.
To get a proper solder joint you always use the wire brush or sandpaper on the inside surface of the fitting just as you do the outer surface of the tubing.
And always sand the tubing a bit beyond the depth of the fitting so you get a good meniscus.
Never tried to sweat soft copper, only rigid. For soft copper, I used a flaring tool and fittings.
I'm just a bit puzzled because I've never had any problem soldering to copper wire even several years old (using std. electronic flux if soldering electronics and such) unless the copper wire was visibly darkened at least a little by oxidation.
Granted that said copper wire is usually stated to be "low oxygen" or "oxygen free", and especially the "oxygen free" types seem to stay new in appearance / not visibly oxidize longer.
In this case the inside surface of the tubing LOOKS new, but you are saying it is still oxidized, right? Maybe some copper alloys are prone to a "clear" surface oxidation layer that the "oxygen free" wire alloys are not? Or maybe "low oxygen" copper doesn't add surface oxidation so quickly?
I do know sanded Aluminum can surface re-oxidize quickly, and even though looking great it has to be re-sanded before soldering. (Using aluminum flux, of course.)
If you don’t clean the surface with a brush or sand cloth and flux, the solder won’t stick.
No. Hahaha! Maybe that’d be a better idea!
I’m actually using these “C” pieces (actually ends up being a sort of “J” when finally installed) for electrical conduction and thermal conduction.
Cleanliness is next to godliness. I have used old flux, 50/50 solder (which you can’t get) 95/5 solder etc. the only thing that really matters is getting the copper clean. The easiest way to do this is with a round wire brush (sold with plumbing junk) but I have also done it by rolling up a strip of sandpaper. Clean BOTH peices to be soldered. Apply flux. put the fittings together. Apply heat to the fitting not the solder. Don’t try to solder it until the solder flows freely when you touch it to the fitting.
Remove heat when the solder flows into the fitting. Don’t fiddle with it till it cools a little.
I’ve actually done quite a bit of copper pipe plumbing, years ago, but always the parts LOOKED like they needed to be sanded or steel wooled. See also my above comments about copper wire (stranded copper wire, actually) vs. this copper tubing.
What threw me a bit is seemingly similar copper surfaces (the wire vs. this tubing, both looking “clean” / fresh) having a much different requirement to solder to it.
Don’t forget the Wonder Bread.
Doesn’t matter how new and shiny it looks, if you haven’t cleaned it today, clean it before trying to solder it.
Sandpaper on the outside, circular wire brush on the inside.
Oh, I have lots of experience with the lead free solders vs. tin/lead! In fact, right here I’m using a nice big spool of 63/37 (eutectic) solder I “lucked in to” on eBay a few years ago.
Brazing would be a problem here - too much heat for a nearby part. And, yeah, hard to get it to look good. I had a neighbor (deceased now) who was pretty good at it.
Well, it WAS years back. Maybe I sanded them and don’t recall it. Just seems like I’d have used some sort of tool for the 1/2” stuff, instead of fat fingers, and I don’t have anything like that in my ol’ plumbing tool box...
Some of those fluxes 40 years back were really aggressive, too...
Yes, I’d just commented about the old fluxes. Maybe those had a good shot of nitric acid in them? Some would eat through clothes if not cleaned off fairly promptly after the job was done.
Usually it’s a cheap wire brush, male on one end and female on the other - they get worn out, clogged up, rusty and useless pretty fast, so since they are cheap I often throw them away when I’m done a plumbing project - maybe that’s what happened.
If your water supply is pH neutral, old school Tin / Lead solder isn’t a thing. If your water isn’t pH neutral, I would move.
Nitric acid is available at www.dudadiesel.com somehow it’s used in making biodiesel although I haven’t the slightest idea how. If you’re cleaning the inside of tubing that will do the job but don’t use it full strength because it will dissolve your tubing while emitting clouds of nasty brown nitrogen dioxide.
“”””having worked in ‘the business’ a while ago””””
What did you do in the plumbing business, or whatever business it was?
“What did you do in the plumbing business, or whatever business it was?”
Mostly residential, assistant, never got licensed as a contractor though.
What is a residential assistant, is that connected to plumbing?
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