Inability to form correct end feed plumbing joint.

[volvomanx]

Hi everyone, I joined recently, although I have been browsing the forums for well over a year. I am not a plumber by trade but I have always completed my own work successfully. I have installed wet central heating in my three previous houses and the only leaks I had have been with compression joints, resolved by a nip-up. I am now changing all the rads in my bungalow, where the pipeing is currently buried in the concrete floors, and running new pipeing via the loft space. My problem is that I am not able to make solder joints without them failing at least 50% of the time. I am doing everything I always do. I have a new pot of flux, for lead free solder. New lead free solder and unused pipe. The copper pipe is though about 12 years old, the remains of my last heating project.
I have looked at the hints and FAQs but remain flumoxed. I am cleaning the pipework with emery/wire wool, applying flux to the pipe then fitting and turning. I have used a smeer of flux, then applied it more heavily thinking the flux was evaporating. I don't think I am overheating the joint, applying heat only until the solder melts. I saw the hint re overheating and causing oxidisation and I have to say, the failed joints do look a bit dark in colour. Often though the solder seems reluctant to flow into the joint, as if the jount is greasy, but I always clean thoroughly. Could I have a duff pot of flux?. Should I be using brand new pipeing?
Your thoughts will be welcome.

 

[doitall]

What flux are you using, LACO is the best.

One common problem with newbee's is they melt the solder with the flame.

Get the fitting hot, and keep touch the join with the end on the solder, when it starts to run move the flame away, and the solder should run into the fitting, you can add a touch more heat to keep it going.

 

[kevplumb]

I am cleaning the pipework with emery/wire wool, applying flux to the pipe then fitting and turning.

you are of course cleaning the fitting

 

[volvomanx]

Hi doitall,

the flux I'm using is Fry I think it says, Powerflow Flux, made by Cookson Electronics, in a yellow pot.
The method you advise is pretty much the way I am doing it, but when I next try I will note what you say about keep the solder out of the flame.
Have you any thoughts about the solder not wanting to flow into the joint, or do you think the change of flux may cure this.

Kevplumb,

thanks for that. Yes I am cleaning the fitting too,

 

[seco services]

can't see nothing wrong with that flux i have a tub of that and it solders just aswell as my LACO, FERNOX FLUX etc. it just stinks abit more.

 

[doitall]

Hi doitall,

the flux I'm using is Fry I think it says, Powerflow Flux, made by Cookson Electronics, in a yellow pot.
The method you advise is pretty much the way I am doing it, but when I next try I will note what you say about keep the solder out of the flame.
Have you any thoughts about the solder not wanting to flow into the joint, or do you think the change of flux may cure this.

Kevplumb,

thanks for that. Yes I am cleaning the fitting too,

Yes as above, you are either melting the solder with the flame or it's not hot enough.

Dip the end of the solder in the flux pot can help a well.

 

[volvomanx]

Thanks again doitall, some good points for me to think about.

Thing is though, when I last did this about 10/12 years ago I had no probs.
Now I'm pants. Must be old age creeping along I expect.

Cheers.

 

[doitall]

Probably a confidence thing.

Have a quick look at the video if the mods don't mind.

http://www.ultimatehandyman.org/videos/206

 

[volvomanx]

Thanks again doitall. I'll let you know how things turn out.

 

[kirkgas]

if the solder is not running you either have a dirty pipe/fitting or you are overheating and the flux is evaporating, and never melt the solder with the blowlamp always use the heat from the fitting to melt the solder, count to 9 while heating the fitting then remove the flame and touch the solder onto the pipe/fitting and it will run a treat

 

[SmithyXL]

Apply the heat to where you want the solder to run to, ie if it is an elbow then to the back of the bend, if it is a coupling then to the centre, the solder is drawn to the hottest part of the joint.
If you are heating the part where the pipe and fitting touch, you are not pulling enough solder down into the fitting itself.
The plumbers that taught me said we had to see the joint very slightly overflow to know it was right.

Best of luck with that.

 

[leakydave]

...and just to add, always solder on an 'open' pipe. If you are soldering 'closed' pipe the expansion of air can burst throught the solder and cause a leak...

but I doubt that is happening on 50% of your joints!