[Shop-talk] Sweat joint leak

[Jim Franklin]

On Jan 18, 2009, at 9:23 PM, John Mitchell wrote:

>   I have a pin hole drip in one of the solder joints in my half inch  
> hot water line.  I shut off the hot water, opened some valves and  
> drained the line out through a spigot I have in the garage.  I  
> thought Id be able to heat the joint enough to get the solder to  
> flow, but I can't get the joint hot enough, even with oxy- 
> acetylene.  Any suggestions On how I can repair this?  It's a very  
> tiny leak, I just happed to be looking up and saw the drop hanging  
> on the joint.  Thanks for any help.  John Mitchell

Like others have said, there is still water in the line that is  
absorbing all the heat. If you open a faucet, eventually you'll steam  
all the water and then the pipe will heat. It is possible to heat the  
pipe so fast that the local area will heat enough to melt solder, but  
you need to be lucky. Flux the area well beforehand, and have solder  
at the ready. Is it possible you're heating to temp, but are just not  
seeing the sdolder melt? If you use new solder, remembering to let the  
pipe temp melt the solder, not the flame, you might see that the pipe  
is heating up more than you think.

jim