Replies

1. 
   davidmeiland | Jul 23, 2006 06:49pm | #1

   You may be putting in too much solder. Just dab a little bit on, top and bottom, and it will get sucked into the joint all the way around. Wipe off the excess with a rag.

2. 
   highfigh | Jul 23, 2006 07:03pm | #2

   Heat the fitting, not the pipe and let the solder "wick" into the joint. A little works better than a lot. You then wipe the excess solder off with a clean rag or steel wool.

   "I cut this piece four times and it's still too short."
3. 
   zak | Jul 23, 2006 09:04pm | #3

   Sounds like you might just be putting too much solder on, which is not a big problem.  It looks nicer if you wipe it off before it cools.

   I always solder from bottom to top, I read to do that somewhere, but I can't remember where.

   zak

   "so it goes"

1. 
   brownbagg | Jul 23, 2006 11:02pm | #4

   heat the center of the coupler. its a talent, but super simple, just keep wiping with solder and when it hot enough it will suck it up and you finish. it takes longer to read this than do it.

2. 
   MSA1 | Jul 23, 2006 11:55pm | #5

   Yep, top to bottom (heat rises why fight it?). I cant remember where I heard it either but thats how I do it.

1. 
   zak | Jul 24, 2006 12:05am | #6

    

   Yep, top to bottom (heat rises why fight it?). I cant remember where I heard it either but thats how I do it.

    

   Did you mean bottom to top?  I thought that's what I said.zak

   "so it goes"

1. 
   MSA1 | Jul 24, 2006 12:28am | #7

   Yeah, bottom to top. I guess thats enough beer.

1. 
   DanH | Jul 24, 2006 01:09am | #8

   No, if you'd had enough beer you wouldn't care.
   If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison

2. 
   zak | Jul 24, 2006 03:56am | #9

   If I'd had enough beer, I wouldn't have noticed.  I'll start working on that right now.

   seeya. . .zak

   "so it goes"

3. 
   ry91 | Jul 24, 2006 07:43am | #11

   Thanks for your help everyone!. Enjoy the beer(s). Bottom's up, and bottom to top it is!

4. 
   RichBeckman | Jul 24, 2006 05:35am | #10

   Someone once posted that you should use as much solder as the diameter of the pipe.

   So if you're soldering 1/2" pipe, then put a bend in the solder 1/2" down and then a second bend one inch down.

   That way you have an idea of when to stop feeding the solder into the joint.

   I probably put too much solder in every time, but I've never had a problem result from it.

   Rich Beckman

   Another day, another tool.

1. 
   JohnSprung | Jul 25, 2006 04:22am | #12

   It is possible to get way too much solder in, and have it flow inside the plumbing, reducing the effective diameter and flow.  But that takes a massive waste of solder and gross incompetence.  If you touch the solder itself to the far side, and watch for it to wick around to the near side, you know you have just enough.  I do top first, then bottom.  Heat rises, so the top will get hot enough to solder just a few seconds before the bottom reaches the same temperature. 

    

   -- J.S.

    

1. 
   sapwood | Jul 25, 2006 05:10am | #13

   I believe that the expression "heat rises" really only pertains to air. Hot air being less dense than cool air, will rise above it. However, in a copper pipe the heat (energy) is conducted through the material. A molecule of copper gets torched.... it gets all excited and arouses its neighbors. They, in turn, pass the new energy on. The molecules don't know up from down. They are equally friendly with all other molecules around them. When I do a vertical joint, I work to fill the bottom first that being the most critical to rely on good capillary flow. With that properly heated and filled, I know that the top is now also ready. But ya know... I don't think it really makes a whit of difference.

1. 
   DanH | Jul 25, 2006 05:16am | #14

   As you heat the bottom joint, lots of hot gasses will rise around the top joint, pre-heating it. I'm sure if you attached thermocouples 2 inches above and below the spot you're heating you'd find that the top one had a temp rise rate about 50% better than the bottom one.
   If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison

1. 
   sapwood | Jul 25, 2006 05:35am | #16

   Yeah, yeah... the hot gasses will do some preheating (although I'm betting that's not what most are thinking when they talk about heat rises). But, I won't buy the 50% increase. My gut and my (ancient) course in heat transfer says the convection from the hot gasses is incidental to the conduction through the copper. Remember, the distances between heat application and joint opening are very small for a copper pipe fitting. To be truly accurate we'd also have to factor in the radient heat transfer, not to mention the cussing (cuz it's cramped here in the crawl space) factor.

2. 
   DanH | Jul 25, 2006 05:45am | #17

   Yeah, the cussing would probably upset the whole experiment.
   If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison

3. 
   JohnSprung | Jul 26, 2006 03:24am | #18

   Instead of trying to figure it theoretically, the way to answer this is with thermography.  Maybe somebody here has an in with a university engineering department that could do it?  

    

   -- J.S.

    

2. 
   plumbbill | Jul 25, 2006 05:30am | #15

   To add just a touch to what Dan said.

   Another reason we solder from bottom to top is that the molten solder will try to run in the direction of gravity.

   So to help capilary attraction we solder bottom to top so the molten solder will sit on solder that is allready at the bottom, therfore buildin up a base .