Soldering copper pipe

[Tim S]

Hi,

Couldn't find this in the FAQ or WIKI (sorry if I missed it).

Spurred on by Dave P's comments on lead free solder, I thought I should tart up my solding skills before attempting any real work, so off to B&Q to get a bit of pipe and some fittings.

I've done yorkshire fittings quite successfully before - I know about cleaning the pipe+fitting and using the correct flux.

This time, I thought I'd try end feed.

Net result, both leaded and lead free joints I did looked like they are sound (need to cut them open to really see) but they also ended up looking like the solder-monster puked up on them! I managed to solder both sides of a straight coupling from one side - so clearly I used way too much solder.

The solder I was using at about 3mm thick (both types) is rather heavier than I'm used to handling for electronics which didn't help.

How do you gauge when you've fed enough solder in? Any tips on getting the pipe to the right temperature would also be appreciated. I heated the fitting with a blowlamp until the solder melted, and then some. I did notice that the lead-free seemed to go from solid to practically water instantaneously, where the leaded had more of a plastic phase.

Cheers

Tim

[Tim S]

Stephen Howard coughed up some electrons that declared:

Hi Stephen,

Flux sound - check. I did notice it making noises - I'll try to pay some attention to this next time. I'm using Fluxite for leaded (because that's what my Dad used) and Powerflow Lead Free Solder Flux for the other.

Ah

'Nads - if I'd known this I might have got a different torch. Mine does have a thumb-wheel - perhaps I can adjust it one handed - I'll try.

That's a very good idea - I'm going to try that. I tend to over do things rather than risk under doing them.

Another excellent suggestion.

Thanks Stephen, I'm going to try again tonight or tomorrow - we'll see how it goes.

Cheers

Tim

[The Natural Philosopher]

Doesn't really matter if you have too MUCH solder..it juts makes an ugly blobby mess..but you can wipe that off while its molten with a thick cloth.

You only need a small ring of solder held in by capillary action inside the joint.

The key to getting that is to wire wool the pipe exterior and the connector interior, if its anything but shiny new, wipe flux all over the ]ipe, strick it togeher and heat te whole lot BEYND the melting point.

Then solder will simply wick into where it needs to go, and, provided enough is in, form a watertight seal. There is no actual necessity to fill the whole hole! I have had mist leaks as a result of not being able to get the whole pipe hot enough, or minute pinholes blown in the solder by e.g. it being the last fitment on a closed system of pipework.

[Dave Plowman (News)]

Sometimes you can only really get to one side - or rather not to the back. The solder monster bit doesn't really matter except for looks. But you can give the joint a wipe with a thick slightly damp rag while the solder is molten to remove any excess. But make sure you don't move the pipes while doing this.

[Stephen Howard]

It's something of a knack really - I tend to rely on the sound the flux makes when it reaches a certain temperature. It gets complicated when you're using solders with different characteristics, as what works for one type might not work for another.

Getting the right amount of solder in is largely down to trial and error ( aka experience ) and what I tend to look for is how fast the capillary action is during the course of the job. It gets tricky near the end of the job because you can reach a point where there's slightly too much solder in the joint, but not so much that the surface tension can't hold it in. One drop of solder past this point and the tension breaks, which results in solder either being blown out of the joint or simply running out.

As regards the heat, ideally you want to raise the joint to the melt point of the solder as quickly as possible - but thereafter the heat should be thought of in terms of maintaining that level rather than exceeding it. With a trigger controlled gas gun you can vary a direct flame - with a standard torch you have to resort to moving the flame off and on the joint ( playing the flame ). One method of determining how much solder to use is to crimp the solder wire every centimetre or so, which acts as a visual guide to how much solder's gone into the joint - if your joint flooded with

3cms then next time you'll know to be cautious once 2cms have gone in.

A simple trick for heavier gauges of solder wire is to flatten it with a hammer.

Regards,

[Andrew Gabriel]

Well, it can hide the joint so you can see if it's soldered properly, and if you've got so much it's run down the outside of the pipe, it may have done the same on the inside too, or left gobs of free solder inside the pipework.

Yes, you can see this by a tiny silver ring appearing around the join.

and inside the fitting

[Tim S]

Andrew Gabriel coughed up some electrons that declared:

I had this on one of my practise joints, so it *can* happend.

I used one of these:

very good.

Cheers

Tim

[Stephen Howard]

It can do - if you put so much in that it breaks the surface tension, it can pull solder out of the joint. Depends how much of a gap there is to be filled. When you come to wipe the joint it reveals a gap, which might go right into the joint. In such cases it might be best to leave the mess - but you might end up with a pinhole sooner or later.

It's one of those 'one in a hundred' likelihoods, but it's sod's law that when you set to soldering a joint there'll be 99 other people out there doing exactly the same job at the same time.

Regards,

[Dave Plowman (News)]

I wondered about that years ago and cut open one which I'd deliberately used too much solder on - and it didn't have excess solder inside. Possibly due to the capillary action only taking what it needs?

[Steve Firth]

I think that's spot on. Soldr gets drawn into the joint by capillary action. When the solder gets as far as the inside of the fitting capillary action is acting in the opposite direction. It is possible to over-solder when the fitting is mounted vertically, of course because gravity takes over.

[Andrew Gabriel]

I've tried a few things, but nothing brings up the shine like a bit of wire wool wrapped around your finger. I seem to have a little finger designed for 15mm fittings, and a 22mm thumb...

For deburring, I use this type of tool

I've got a better Record one (don't think they exist anymore). Need to be careful you don't slip and take your eye out with it though.

[Dave Liquorice]

Shouldn't need much more than 1cm of solder for a single end on 15mm tube.

Remember to heat the pipe as well as the fitting, the heat will travel up the pipe into the fitting better than it does across the small air gap between the pipe and fitting.

Not paid any attention to the noise the flux makes, I go by how long the blow lamp has been played across fitting/pipe then when I think it should be hot enough start to dab the solder onto the joint between fitting and pipe at the top. Onec it's hot enough it'll just melt and be drawn in and as I say above only about a cm is required.

[Tim S]

Andrew Gabriel coughed up some electrons that declared:

>

although I've got a better Record one (don't think they exist

the one I got.

It's a bit rough but it knocks most of the lip off that's left from using a pipecutter.

Cheers

Tim

[Cicero]

>>

> although I've got a better Record one (don't think they exist

is the one I got.

========================================= Old style tube cutters have a built-in reamer for de-burring as shown in this rather stylised picture:

[Tim S]

Dave Liquorice coughed up some electrons that declared:

OK - so 1cm + little bit for 22mm,

Oh - I didn't do that. Maybe that's why nothig happened for ages, then it suddenly "went" - I suspect it was overheated by then.

I did my two joints 4cm apart and the leaded joint (done first) is showing the classic signs of being overheated.

Thanks Dave.

I'll have another go.

Cheers

Tim

[John Rumm]

Probably not a bad topic for an article.

Generally I find end feed 100% reliable, and yorkshire 99.9% The thing that makes the end feed easier is the lower thermal mass, sou the fitting and pipe heats faster and there is less chance of there being a cool spot to make it go wrong.

Generally you need far less than you think. If you look at how much is in a yorkshire fitting, it would probably equate to less than a cm of solder from the spool.

Leaded plumbing solder is designed to be non eutectic so that you have the ability to work it in the semi molten stage (wiped joints etc). The lead free is almost a single metal, with very little alloyed into it. Hence it is almost eutectic, and behaves much more like electronics solder with a close range of temperatures between solid and fully liquid.

Personally I usually heat the fitting and pipe from approx a 6 o'Clock position, and then test the temperature with a quick dab of the solder wire from above (i.e. out of the flame). Once to temperature, you can watch the first dab be sucked into the joint by capillary action. Then add a second, and then that is enough. Any more will usually end up running somewhere you don't need. A wipe with a thick slightly damp cloth while still molten will leave it looking pristine.

[John Rumm]

I have one of those, but find it an tad awkward and scratchy! The end brushes being very good for snagging all sorts of stuff while in your bag.

Wickes do a blue cylindrical pipe brush / debur tool that is easy you use (one end does 15mm the other 22) and you just stuff it on the pipe and twist a couple of times. Very good for cleaning up pipes in place, since it will work close to a wall.

[Tim S]

Tim S coughed up some electrons that declared:

You're all geniuses!

Just done another two joints - leaded and unleaded. Using the 1cm of solder as a guide, a bit more care heating the pipe as well as the fitting and wiping off with a damp bit of kitchen roll, I have two joints which look as good as any I've seen a plumber do :)

Looking in the end (I only did one end of each coupling) it seems that the solder ring has just appeared at the end of the pipe inside the fitting and appears all the way around. Minimal solder on the outside of the pipe prior to the joint, and having been wiped off, it's not ugly - more of a silvering of the pipe. No blobs at all.

I was so pleased, I polished them up with a bit of 00 wire wool.

My technique for gauging the solder was to put a slight bend in the wire 1cm from the end and solder upto there.

Again, mega thanks - won't be using yorkshires now.

Cheers

Tim

[The Medway Handyman]

I had/have one of those & they work well, but the brushes didn't last that long. Well, TBH mine was a Silverline version of the Wickes one, so that might be why. I bought one of these

which seems much quicker at cleaning & better made. Time will tell.

[Dave Plowman (News)]

Most of my joints are concealed under floors etc and I don't bother worrying about looks on those. I'm more worried about moving things if wiping off excess solder and causing a dry joint. But of course all should be wiped with a damp rag to remove any flux after cooling, especially if using an aggressive type. Other tip for awkward ones is to use a torch and mirror to look at the back to make sure the solder has flowed to there.

I'm interested that other have said lead free flows more easily - doesn't explain what went wrong with mine. Although it wasn't all the lead free ones I did - just two out of about 20. But I'd got used to never having problems with end feed before.