Soldering Troubles!!

Tonight I was helping a friend add some plumbing to his basement that he is finishing, we dry fitted all pipes, and I started to solder some of them, it is not often that I sweat pipes but have never had any major trouble before. This time was a different story!! I started soldering the most easily accessed joints first hoping I would get the hang of it back as I got into the tighter spots, but I could not get any solder to flow hardly at all, I cleaned and fluxed both the fitting and pipe thoroughly, I was finally able to get a joint to join but I still was not happy with the results. Could it be the products I'm using? I'm not saying my technique is perfect but I have never had trouble like this before, its kind of embarrassing when you look like a complete fool in front of the person who you told that it would be "no big deal" to. Here is what I was using. If these products are inferior recommendations would be appreciated.
I can't find the exact solder on Lowes' website but here is the link to the kit I bought and a pic of the flux.

Thanks for your input,
Jake


http://www.lenoxsaw.com/Pages/Product.aspx?productId=4OzPlumbingKit

Those products are fine. Here are some tips:
> must be absolutely dry..no drips whatever
> you already mentioned cleaned well
> lead free solder flows at a higher temp, so you have to get a good flame on the FITTING, get it hot, flow the solder, and get out! If you have heat on the joint for more than about 30 to 45 seconds, good chance the flux will burn and the solder won't flow.

Jacob Robinson said:

...we dry fitted all pipes, and I started to solder some of them...

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By dry fit, do you mean with flux, or did you dissasemble and reassemble with flux. I'm not familair with that particular flux, but with some brands, you cannot leave it too long before it oxidizes. I don't dry fit the whole job. I only dry fit complex areas and then dissasemble, flux and solder a few fittings at a time.

If this isn't all "new" work, and you didn't every drop of water out of the pipe near where you're working, the solder wont flow or wont seal up 100%.

By dry fit, do you mean with flux

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All joints were fitted prior to any cleaning or fluxing.

If this isn't all "new" work, and you didn't every drop of water out of the pipe near where you're working

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This is all brand new work except where I will tie into the old line. (hasn't been done yet, I was planning for that to be last fitting to sweat)

good chance the flux will burn and the solder won't flow.

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I wondered if I did over heat the joint, but I am making sure that as soon as the solder will melt on the pipe I remove heat and apply solder. Almost as is the temperature at which the flux burns away is lower than the melting point of the solder.

a few of the fittings have barcode tags on them, will the smoke for the paper burning contaminate the joint? I'm just fishing for causes here.

What color is the tip of your flame? Does the flame come to a point or is it "dancing".

If it isn't pointed and blue you may simply need a new nozzle.

Jacob Robinson said:

All joints were fitted prior to any cleaning or fluxing.



This is all brand new work except where I will tie into the old line. (hasn't been done yet, I was planning for that to be last fitting to sweat)



I wondered if I did over heat the joint, but I am making sure that as soon as the solder will melt on the pipe I remove heat and apply solder. Almost as is the temperature at which the flux burns away is lower than the melting point of the solder.

a few of the fittings have barcode tags on them, will the smoke for the paper burning contaminate the joint? I'm just fishing for causes here.

Click to expand...

once or twice in the past, when I used copper fittings with those stick on bar code labels, I did have a problem where the glue did contaminate the joint. I now always remove those labels if there is one. All the HD and Lowes individual items have them unless they are in plastic bags

That water soluble flux WILL burn and contaminate the joint very quickly if you overheat the joint

I've soldered a lot of things, and found that flux to be horrible to work with. Now, if I did it every day, maybe it would be fine. I ended up getting a flux with solder in it and everything went together fine. That was the first time I'd used (I think it was called) tinned flux, all other times, I'd used a different type.

I always use the Oatey flux in the past few years #5 or 95, I forget, but the one without the tinning. For so many years before that, I used to buy the little tin cans of "Nokorrode" flux, which always worked well for me. I still have 2 old rusty cans of that I should throw out. Maybe I already did.

I haven't had a chance to go back and give it another whirl, but I was thinking that I would get some Oatey No. 95 tinning flux. The website says it will never burn out (I'm sure this is a relative statement, but it still has to burn off at a higher temp than the Lenox water soluble that I currently have). It seems to me that pre-tinning could do nothing but help the flow of the solder. Am I wrong? Would I be better off with No. 5 Paste flux?

I use Oatey No. 95 and it has always worked well for me.

Lenox also makes a tinning flux that you should be able to find at Lowes. It also helped me to use a solder with a slightly lower melting point (Lenox's version is "Sterling").

I ended up getting some Oatey No. 95 Tinning Flux, IT MADE ALL THE DIFFERENCE, I soldered up about 25 fittings in the Hot/Cold run and hot not one bad joint. Maybe if I did it more oftern I could get the water based flux to work, but for now I'll stick with what is working for me.



Another question I had is about flushing the lines after sweating them. The job is a DIY bathrom that is quite a ways from being finished, maybe 6 months or so, and I was wondering if flux will due any damage to the pipe if left unflushed for such a period of time. I wiped all joints on the outside but will flux sit on the inside of the joint and start to eat at the pipe if not flushed, or does it evaporate when heated? The pipes are 3/4" and 1/2" Type M copper.

The flux will not eat your pipes.

The flux "evaporates" when it is heated. I used tinning flux many, many years ago. In fact I was out in the boonies one time and had to make a joint but was out of solder. The tinning flux soldered the joint by itself.