Pipe soldering technique

[andrewpreece]

I had this problem, and it's bugger to solder pipe which has even a drop of water in it. The answer, I found, was to clean the inside of the solder fitting ( I used end feed ) with iron wool, as well as the end of the pipe; it's only logical that both surfaces to be joined shoud be bright if you think about it. Now for something slightly contentious; I was using a mild flux at first ( comes in a round metal tin rather like shoe polish does ), but a neighbour demonstrated to me a flux called 'Everflux', and he could reliably join pipe that hadn't even had the oxide layer cleaned off. I say contentious because it's probably an active acid flux and some folks here may think using an acid flux is the sign of a bad workman! At any rate, it's best to clean it off the joint afterwards. I reckon just cleaning the pipe AND the inside of the fittings will give a decent joint even with a mild flux though. Clean both surfaces, then smear them both with flux, join them together and go for it. I don't think the choice of solder has much bearing on things.

Andy.

[Roger Moss]

I have finally put water into my central heating system. The bits done by a plumber didn't leak. The bits I did, despite (a) thinking I knew all about soldering and (b) being absolutely paranoid about cleaning the pipe, smearing it with flux etc, had about 4 leaks. Draining down the system to fix them is a real pain (and one of the ones I've fixed has just stared leaking AGAIN!).

Is there some secret method of guaranteeing a good joint? The ones I did in the open air (holding it up and playing with it) are OK - it is the ones in tight corners, assembled and then heated, that have gone wrong. When heated and pulled apart I can see that the joint was completely dry - just a ring of solder around the exposed end.

Should I use NON lead-free solder? Should one use a small, hot flame or a larger burner running gently? (I have a propane bottle & Sievert blow torch). Is one better off with solder-ring fittings (which I had) or plain ones, tinned by hand?

I'm now draining it down again and hope this will be the last time.

Thanks Roger

[Rick Dipper]

I am not the an expert, you need IMM for that, but I was taught ...

Heat the pipe, not the solder.

This means, that you should be able to take the heat gun off the join, as you melt the solder on.

However if you overheat, its back to disasterville.

Rick

[mike ring]

"Roger Moss" wrote in news:cn8hi8$c8b$ [e-mail]:

Perhaps you're not heating enough in the enclosed space. Have you got a heat mat?

The only other thing I can think of is that perhaps the ends of the pipes you soldered in situ weren't open - air heated in soldering and expanding can blow your joint (I think, in any case I wouldn't chance it) or had valves or taps that were closed.

I'm a very amateur plumber, but I've only had 2 failures, one was picking up a tee I hadn't prepared instead of the one I had, and the other was a distorted pipe, sso I really believe if you do it right it will work.

Your last sentencee bothers me - I don't tin the pipe or fitting, as I would with electrical soldering, as I think I could not assemble the parts, and if it were tinned, how could it be *completely dry*.

I suggest you don't try to tin, that's the flux's job, just clean with wire wool, apply flux, cook enough but not too much (IMO the only remotely tricky part), and apply any solder that is sold for the job

I actually prefer endfeed, they feel a bit more secure feeling the solder run in, but I'm old fashioned enough to use solder ring on a vertical uphill joint - my faith isn't quite strong enough!

mike

[Peter Stockdale]

...

I have always used solder ring fittings using standard preparation techniques. In addition I always apply extra solder from a role to both ends. Never had a leaker yet.

Pete

[logized]

I recently installed a new CH system, I used mainly solder ring fittings (because they should be more likely to work). If you heat the fitting evenly, then the solder eventually appears at the joint and just to make sure, apply a small amount of solder to it then. You mentioned cleaning the pipe - did you also clean inside the fittings? - if not, then that would be the problem. Also, It is a good idea to use a small brush to smear the flux onto the pipe and inside the fittings (not too much though) As a last resort, I noticed that there are stronger (power) fluxes available that don't require the pipe/fittings to be cleaned so much - but the downside is that these would be more corrosive if left in the system. Another good idea for cleaning pipes is to use a green nylon abrasive cloth (available from plumbers merchants) - these are a LOT like dish cleaning cloths and have the advantage of not causing problems of leaving behind any wire wool particles. I did have a problem with a bag of 22mm solder ring elbow fittings though - these were all faulty manufactured so that the one side of the fitting was too tight to slide the pipe in easily. (they had too much solder in the solder ring) After wasting time trying to make them fit properly, I gave up and replaced them.

Dave

[Mark]

I don't use a large torch under-floors for 15mm, a camping gaz torch works fine for me its small and the refills are only 90p. I don't use a matt either just a piece of flat metal bent like an S that will fit under joint to be soldered. When heating I play the flame back and forth over the fitting and the pipe for a few inches either side, for a few seconds, and then melt a small bit of solder at a join, keep heating until this runs. Fitting and Pipe are now hot enough, move flame onto pipe away from join and apply solder that has been dipped in flux , do the same for other side. Job done !

[Dave Plowman (News)]

Then you've not heated the joint enough.

Play the torch gently back and forth over the joint - but if anything make the part furthest away from the pipe slightly hotter so when applying the solder it must be at least as hot. You should also be able to see the solder being drawn in.

There's no reason why you can't test for the correct temperature on the part of the fitting furthest from the pipe by applying some solder there - if it melts it must be ok. Maybe not neat - but not a problem if not on show.

I like a large relatively low temperature flame - ordinary calor gas suits me.

You don't tin anything, though. Just make sure everything is reasonably clean and use an aggressive flux - washing the exterior clean afterwards.

[Dave Plowman (News)]

What's the point in using yorkshires if you're going to add solder? They're a great deal more expensive.

[Andy Dingley]

And why _are_ they called "Yorkshires", when they're the expensive sort?

[Andy Dingley]

If I'm working upside down with my head in a cupboard I always use the big torch (with a hose and a floor-sitting cylinder). Unlike my little hand-held cylinder torch, this one doesn't flare if I shake it or turn it upside down.

[wounded horse]

Don't use steel wool - get one of those red scratchy pads. Steel wool can leave strands inside the pipe and then it gets in to the flux which is not good.. If the pipe is cleaned using the pad, fluxed continuously and heat applied all round until the solder shows around the edge you'll have a good joint. As soon as the silver ring appears at the edge of the fitting/inserted pipe(make sure it's all the way in) get the heat away. Not another second. Buy five quids worth of solder ring fittings and a length of pipe and practice. You don't need extra solder.

Glyn

[Peter Stockdale]

If it is a small job being done then the extra few pence per two or three joints is not worth worrying about. If it is a large job -say full central heating installation, then you would only increase your materials cost by perhaps one to two percent. Well worth it if it eliminates the chance of leakers having to be sorted later. Regards Pete

[Dave Plowman (News)]

Think they held the patent. Dunno if it's run out by now.

It's a sort of 'Hoover' name.

[Owain]

"Andy Dingley" wrote | "Dave Plowman (News)" wrote: | >What's the point in using yorkshires if you're going to add solder? | >They're a great deal more expensive. | And why _are_ they called "Yorkshires", | when they're the expensive sort?

Because it's Yorkshire that's doing the selling, not the buying?

Owain

[Dave Plowman (News)]

I'd rather buy a bulk pack of the common fittings. Likely to cost no more than a few individual bubble packed yorkshires in the same shed. Even in bulk, yorkshires can be twice or more the price.

But I'm saying it won't. Either type will work fine if you solder correctly. And it might be said to be easier to see good solder flow on an end feed type.

And buying a bulk pack makes even more sense if a beginner. Practice a few times and see what works and what doesn't. Take a trial joint apart and check how well it's tinned. At only a few pence each you just throw them away afterwards.

[Craig Graham]

What's the problem with overheating? I've not had molten copper yet. I work on the basis of the hotter the better, and the more solder the better. The only time there's a problem with that is when things aren't adequately supported and the other side of the fitting falls off the pipe! And when you melt a plastic isolator valve you forgot to take off.

I'm pretty sure I use acid based flux as well. Why's this considered bad? If it increases reliability then I'd consider it to be good.

[Dave Liquorice]

All the flux burns away and the chances of ending up with a dry joint increases dramatically.

But not so much that in runs inside the pipe and causes a blockage or restriction I hope... Hot enough so the solder flows and just enough solder to form a ring between the fitting and pipe. On normal 1/8" or so dia solder and a 15mm fitting thats about 1/4" of solder melted in. Judging the temp is tricky but after a while you get to know your blow lamp and how long it takes to get a given size of pipe up to temperature, thats what experience teaches you and you have then gained a skill.

Outside it causes corrosion if not completely removed, that nasty green gunk around old joints that looks like a tiny leak. Inside on water supply pipes it's probably not a great issue as the flow of water will flush it through but on sealed systems, CH pipework for example, you increase the risk of corrosion damage and/or reduce the effect of any inhibitor.

[Dave Plowman (News)]

It can continue causing corrosion. You can wash off the outside, and if water in the pipes, this will do the inside. Problem is with gas.

[Pete C]

Try fluxing the inside of the fitting as well as the pipe, and wipe off all but a small amount of flux. From practice, find out what length of solder is needed for a typical fitting.

Heat the fitting from nearer the middle and work towards the end, playing the flame perpendicular to the pipe, so when the end is up to temperature, the rest already is. If the fitting is horizontal feed solder in from the top.

Practice working overhead on a few sample fittings, then cut them open with a grinder to see how they turn out.

cheers, Pete.