Pipe soldering - what went wrong?

[andyste]

I had some pipes to replace/reroute at my mum & dad's house today. In the past I've always shyed away from soldering and used compression fittings, but thought I'd give it a go this time. I swotted up on the web (clean with wire wool, paint flux on the pipe end, fit together, heat for 15-20s at the tip of the bright blue flame). How hard could it be?

The first problem was that the blowtorch flame kept "flaring", basically erupting into big orange flames. Not sure if it was because the torch (https://www.toolstation.com/gosystem-auto-start-blow-torch/p51854) didn't like being pointed down at an angle? Or was it too close to the work area perhaps, starving the torch of fresh air and sucking the hot air back in?

The second problem was that on the few (horizontal) joints that I did tackle, the solder just wasn't running into the joints, and was instead forming blobs and running off the pipe.

Any suggestions on what I might have been doing wrong with both issues?

Needless to say I went back to compression fittings, which was a shame as I'd really liked to have cracked soldering this time round, having last tried it 25 years ago with similar results.

 

[kidgreen61]

Sounds like there was a drop of water in the pipe, it only takes a few drops to absorb the heat from the torch, and WILL NEVER SOLDER.

 

[ericmark]

Likely right about the flame, I found there are two solders, 40/60 and 60/40 one for plumbers which can be wiped, and other for electricians which flows very well, I would cheat and use electricians solder as it flows into joint easier.

It has to be very clean, but also a problem with flux, the flux for lead/tin solder is quite basic, and the fumes are not too bad, but the flux for solder without lead is nasty, I don't like using as a result, it needs extractor fans running when using, so today normally use plastic compression fittings unless it is where it can be seen.

leadless solder may be safe, but the flux it not.

 

[Old Salt]

The flaring could be caused by some “liquid” gas entering the nozzle. Let it warm up for a bit before using and try to hold it upright. I am not good a soldering pipes but it may have been too warm?

 

[CBW]

I wouldn’t use electrician’s solder as it my contain lead, which isn’t suitable for potable water. It might be ok on a heating system, but wouldn’t know.

 

[SpecialK]

You need a better torch head. Mine always did this. Bought a rothenberger and yellow map gas canister... would never go back... Expensive though.

 

[denso13]

Sounds like some water in the pipework to me as well. It isn't difficult to solder at all if everything is clean and fluxed.

 

[RandomGrinch]

As above, soldering isn't too difficult.
I prefer to use solder ring fittings (make sure these are cleaned inside and fluxed as well).
I also like to use Scotchbrite to polish up, as it works as well as wirewool, but if some does end up in the pipe, you don't end up with rusty bits of steel circulating in your system!
If you feel like trying again, buy yourself a few solder ring fittings and have a play! All sorts of things can be made with pipework, it doesn't have to be just plumbing
And getting it right can be a really satisfying experience

 

[Keithmac]

You need a better torch head. Mine always did this. Bought a rothenberger and yellow map gas canister... would never go back... Expensive though.

We use a Rothenberger at work with Yellow Map gas.

Bought the same kit for home (Torch + 2 cylinders in a case) , I would say it's a bargain for what you get!.

 

[Keithmac]

Blobbing solder is not enough heat or not clean enough to start with.

 

[RandomGrinch]

Sounds like there was a drop of water in the pipe, it only takes a few drops to absorb the heat from the torch, and WILL NEVER SOLDER.

Just to mention, I find the biggest problem with a couple of drops of water in the pipes isn't that the junction wont get to temperature, but the steam created by the heat will perforate out through the molten solder, creating a porous joint.
...and it can spit a nasty blob of solder out at you! - Always wear safety specs when soldering folks!

 

[SpecialK]

We use a Rothenberger at work with Yellow Map gas.

Bought the same kit for home (Torch + 2 cylinders in a case) , I would say it's a bargain for what you get!.

Saves countless hours looking for a lighter every time too!

 

[Dereekoo]

Use yorkshire fittings and heat the pipe to the side of the joint and the solder will be drawn out of the fitting to give you that nice silver ring around the circumference. Keep blow lamp vertical..