Fixing CFC Leaking Welds

[beerrepository]

I tested my CFC I built tonight and unfortunately it has a few leaks at one or two joints. I already blew through a copper t-fitting in my quest for knowledge and experience with soldering copper. Is it safe to heat the joint again and re-apply solder or should I look at something like JB-Weld to just patch the pipe?

 

[thomasrj]

I might go ahead and heat the sucker up and take it off. Then clean it up good, get all the old solder off of there, and resweat the joint. Joints always come out better when you are working with a fresh, clean fitting.

By the way, this advice is coming from my plumbing experience, and not from my extremely limited brewing experience.

 

[beerrepository]

the problem is that one of the joints is a reducer being slid over 3/8" refrigerator tube, so in order to clean it, I basically have to take the whole thing apart and even then I can really get solder paste into the joint because it just gets smeared when I slide the reducer over the pipe.

Also just to be clear, I build the CFC in the Wiki.

 

[kcinpdx]

I had the same issue with the same set up and could never get it right. I took it apart cleaned and re-soldered twice with no luck. So now I've got a slightly leaky CFC that works very well. Fortunately it is only the water around the pipe that leaks, so no contamination issues.

 

[KCBrewer]

If your solder joints aren't taking well, you are most likely getting it too hot.

Take it apart, clean/sand both sides of every joint until it looks like a shiny new penny, put a liberal amount of flux on both sides of the joint and reassemble. Apply heat to the thickest side of the joint for about 5 seconds then touch the solder to it. If it melts/flows, back the heat away and let it flow. If the solder begins to stiffen up, just brush the flame past it again to keep the solder flowing.

The easiest mistake to make in soldering is to keep the flame on the joint too long. Heat becomes your enemy quickly. Your flux burns up and no solder is wicked into the joint.

 

[Bobby_M]

While I agree that overheating is a typical problem, I think dirty pipe/fittings is just as common. Did you use one of those inside and outside wire brushes to get everything really shiny? Did you keep your fingers off of that area afterwards?