redoing copper sweats

[Pronouncedeyen]

Hi all. I screwed up and need to redo a couple joints I sweat last night. I was planning to cut them away and start over but some people on the site say you can just heat up the joint, pull it apart, flux it up again, and redo it.

The problem I have is that when I pull them apart there's solder on both pipe ends and inside the joint. I have a very hard time putting them back together. Do I need to remove the solder from the pipes first? Can that even be done?

Also, if I do get them back together, do I need to feed more solder in there or will the process of heating them back up again seal the joint?

Thanks all!

 

[Jimbo]

The problem I have is that when I pull them apart there's solder on both pipe ends and inside the joint. I have a very hard time putting them back together. Do I need to remove the solder from the pipes first? Can that even be done?

Also, if I do get them back together, do I need to feed more solder in there or will the process of heating them back up again seal the joint?

Thanks all!

To reuse, you would need to try to wipe the pipe, and knock the solder out of the fitting, while still hot. Easy enough to do on the pipe. Fittings can be a little harder. Most folks would use a new fitting, just to save time...but copper is not cheap these days!

You will want to reflux the joint, and flow some new solder. The solder which remains will "tin" the joint and make it flow easier.

 

[Sponsor]

 

[Gary Swart]

Just use a dry rag to wipe the outside of the pipe while it is still hot. Do be careful, that hot pipe can give you a burn you will remember for a long time! The inside of the pipe and fittings is more difficult, but I have use a fitting brush to get at least some of it out and spread the rest around the pipe. You won't get it all. Unless I am at the end of my job and have no more fittings, I won't even mess with cleaning them up to reuse, but in a pinch, it can be done. You do have to get the old solder in the fittings quite smooth as the tolerance for fitting pipes to fittings is quite small.

 

[Herk]

Pooh! What's cheaper, a few copper fittings, or a flood? Toss 'em in the recycling bin and start over. There was a reason they leaked.

 

[Pronouncedeyen]

To reuse, you would need to try to wipe the pipe, and knock the solder out of the fitting, while still hot. Easy enough to do on the pipe. Fittings can be a little harder. Most folks would use a new fitting, just to save time...but copper is not cheap these days!

You will want to reflux the joint, and flow some new solder. The solder which remains will "tin" the joint and make it flow easier.

Thanks Jimbo. I'll use a new fitting - no problem. You think wiping the pipe when it's hot will remove the solder? Just wipe with a rag?

 

[Charles2000]

Yep

I've done this too. Yep, just wipe with a rag. I wipe immediately after sweating a joint too, just 'cause it looks prettier.

Charles

 

[Pronouncedeyen]

Update: I got the joints off easy but I couldn't get the solder off the pipe! I tried wiping with a rag and heating it up again but no dice. I was able to fit a new joint on top of it though so I put a ton of flux on it and resoldered it. Hopefully it won't leak.

 

[Jadnashua]

You'd never easily get the soldered pipe end to look like copper again, but a thin coat of solder there actually makes the joint better. The goal is to wipe the excess off so you can fit a new fitting onto it, not get it shiney copper colored. What you ended up with is a 'tinned' surface.

 

[lottia]

Solder-sucker

I used to assemble electronic circuit boards before most of the process was automated. We used solder-suckers to remove solder. I've used two types--one is just a squeeze bulb of heat-resistant (silicone?) material, the other is a spring-loaded syringe-like contraption. In either case, one heats the solder, then sucks it away.

Are these ever used in plumbing applications?

lottia

 

[hj]

suckers

We do not have circuit board type solder joints. All of ours are too large for a small sucker, and it would not suck the solder out of the joint anyway.

 

[Jadnashua]

I doubt they are used in plumbing...as opposed to a land on a circuit board, a sweated pipe joint is just too big to vacuum out the solder nor would SolderWic work very well.