Soldering.. copper to copper OR copper to brass.. which one?

Lithnights · Mar 16, 2006

I have researched this one here on the forum but can't find an answer..

I want to replace a couple of old shut off valves with new ball valves (most seem to be made of brass) in my accessible basement. I want to sweat them.

I believe I can do this 1 of 2 ways..

1) Buy a threaded shutoff valve, screw in a threaded adapter, then sweat the adapter to the incoming pipe. Then do the same thing for the outgoing pipe. Thus sweating copper to copper.

OR

2) Buy a non threaded shutoff valve, and just sweat the valve to the incoming pipe. Then do the same thing for the outgoing pipe. Thus sweating copper to brass.

I would think number 1 would be easier to do based on what I've read about it more difficult to solder to brass. Is that true?

What is the easier/better alternative?

Or if I'm completely wrong in my analysis/options, please let me know.

Thanks!

Prashster · Mar 16, 2006

There is no problem soldering brass to copper or vice versa. Brass contains copper, and behaves similarly w/r/t soldering.

I prefer solder to threaded joints, unless you anticipate future removal AND you won't have enough room to cut out.

That being said, soldering both ends means you have to be doubly careful not to damage the valve. When soldering one side, you should take care to solder with the valve opened, and with a wet rag around it and the other side (so you don't melt that solder). This is the easiest way.

Sponsor · 2022-01-29T12:20:58-0800

Kristi · Mar 16, 2006

brass and copper are materials that you solder together... it is the way to go, don't mess around with threaded adapters and such, you are asking for a whole new host of issues (overtightening, undertightening)! Just make sure to clean the valve and copper pipe pipe till it's beautiful and bright all over the areas to be soldered and keep the valve OPEN while you're soldering - if you are novice at this, then I'm going to make the assumption that you may possibly overheat and cook the inner bits of your valve by mistake. This means that you will do a lovely job on the outside, when you turn the water on it will appear to be perfect, and when you shut it off (at a time when you need to!) it won't fully close or stop the water... just letting you know what can happen - my very first soldering job was a soldier line up of 40 valves needing poly B adapters... I definitely buggered up at least 20 of them, and that number could be much higher but my youthful pride at the time wouldn't allow the truth to remain in my memory

It took practice practice practice for me to figure out that you aim the flame away from the valve body while soldering, it's like you want to heat the end of the copper inside of the female end and solder around the edge of your valve... lots of novices think you torch the sh-- out of the edge where you actually solder, like you have to melt the solder and have it cap the edge... not so, you want it to flowwwwwwwww into the adapter and finish in a completed rim around the edge. Maybe do some practice pieces before you you go whole hog on the actual repair, otherwise you may need to have a plumber lined up as backup in advance!

Lithnights · Mar 16, 2006

Kristi said:
brass and copper are materials that you solder together... it is the way to go, don't mess around with threaded adapters and such, you are asking for a whole new host of issues (overtightening, undertightening)! Just make sure to clean the valve and copper pipe pipe till it's beautiful and bright all over the areas to be soldered and keep the valve OPEN while you're soldering - if you are novice at this, then I'm going to make the assumption that you may possibly overheat and cook the inner bits of your valve by mistake. This means that you will do a lovely job on the outside, when you turn the water on it will appear to be perfect, and when you shut it off (at a time when you need to!) it won't fully close or stop the water... just letting you know what can happen - my very first soldering job was a soldier line up of 40 valves needing poly B adapters... I definitely buggered up at least 20 of them, and that number could be much higher but my youthful pride at the time wouldn't allow the truth to remain in my memory

It took practice practice practice for me to figure out that you aim the flame away from the valve body while soldering, it's like you want to heat the end of the copper inside of the female end and solder around the edge of your valve... lots of novices think you torch the sh-- out of the edge where you actually solder, like you have to melt the solder and have it cap the edge... not so, you want it to flowwwwwwwww into the adapter and finish in a completed rim around the edge. Maybe do some practice pieces before you you go whole hog on the actual repair, otherwise you may need to have a plumber lined up as backup in advance!

I hear what you are saying about overheating.. that is a big concern of mine. But I actually have been practicing a couple joins to make sure I have it as good as I can do. And I have watched a video (found on this forum) on the proper way to do it. That is no substitute for the real thing though I know. I guess that's why I was originally thinking of using the threads.. less of a chance of doing any damage to the valve since I wouldn't be soldering the actual valve...

Also, I am planning on using a ball valve which I understand has less "parts" and is tougher to "ruin" than the older, cheaper valves that have multiple washers in them. True??

Thanks for the advice

Prashster · Mar 16, 2006

1/4 turn ball valve is more reliable over time than the faucet-style 'gate valve'. Over time the gv can have a tendency to fail to close fully. You're right. The 1/4 bv is a simple mechanism with better integrity.

Gary Swart · Mar 16, 2006

And the 1/4 turn ball valve is 30 times easier and faster to turn off and on!

Cass · Mar 16, 2006

If you are concerned about harming the valve with heat from the torch then solder on male adps. cool them and then teflon tape them and screw into a threaded BV. This way you will not harm the valve. If your brave go for the sweat BV.

milly555 · Feb 28, 2010

I think it is not very important to choose which method,you should pay more attention to the qulity of the valve,that is to say,you should make certain the materil of valve so that you make sure the duration of the valve,you may refer to http://www.ecvv.com/product_directory/Brass-Valve.html

hj · Mar 2, 2010

IF you install the threaded adapter INTO the valve and then solder the tubing to it, you can be almost assured of having a leak. If you are going to use a threaded valve, you solder the adapter to the copper, THEN screw the valve on when the joint cools. If you can make a good joint to the adapter, you can solder the valve just as easily. And, they are ALL made of brass, unless you pay a lot extra for something exotic, such as stainless steel, or you need one for to connect to a plastic pipe.

Soldering.. copper to copper OR copper to brass.. which one?

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