Tips on using end-feed plumbing fittings?

[Lobster]

Following swiftly on from yesterday's plea for help using microbore tubing (for which, many thanks for the replies!) I've been to buy various fittings from the plumber's merchants and foud that the range of these is graetly restricted in Yorkshire fittings compared with end-feed items (presumably because that's what the pros normally use). So I've decided it's time I bit the bullet and started using end-feed fittings, Should save myself a few bob too!

I'm reasonably experienced with Yorkshire fittings and have no problems using them. What I'm not clear about, in transferring my skills to end-feed fittings is (I think) how you tell whether you've got solder down the copper-copper interface, and enough of it to make a proper joint? Easy enough with Yorkshires, when you see the silver ring appear...

Thanks as ever

David

[Mungo "Two Sheds" Toadfoot]

Flux the joint as usual, apply heat to the whole joint, when the flux bubbles apply solder to two or three places around the joint. Capillary action will suck the solder in and when you see a whole ring of solder you're done.

Lead-free solder doesn't flow as well as leaded.

Si

[Dave Plowman (News)]

Exactly the same with end feed. Stop feeding solder when a ring appears. If you can apply the solder to the 'back' so much the better.

[John Rumm]

If anything I find them quicker and easier than solder ring fittings since they (having less metal) get to the right temperature slightly faster.

Prep and flux as usual, apply heat to the joint and wait a few secs, then offer up the solder to the joint and touch it on to see if it is hot enough to flow. Once it is, the solder will flow easily. Feed in about half an inch or so (assuming you are using typical plumbing thickness wire). You will actually see the joint suck the solder in. Once you have added solder, withdraw the heat, wait for a few secs and then wipe of any excess with a damp cloth for a neat finish.

[Lobster]

Hmm. So far, I'm afraid all my prejudices have been confirmed... Having armed myself with a length of 15mm tube and a few straight end-feed couplings, I've been having a play today. One time, it did seem to work OK, and I achieved the 'silver ring'; however, other times the solder just ran off the tube like water off a duck's back and landed on the floor, nothing being sucked up into the joint.

I'm guessing the heat wrong? Any more tips, anyone, maybe for getting the right temperature, if that's what it is?!

Thanks David

[John Rumm]

It sounds either like the pipe was either not chemically clean, or the pipe was not hot enough, and you were just melting the solder in the heat of the blow lamp. This is why it is important to heat the pipe/joint, and allow the heat of the pipe to melt the solder and not the flame.

For soldering to work, the joint must be physically clean (wirewool, wire pipe cleaning brush etc - i.e. nice bright metal), it must also be chemicaly clean (no oxide coatings, grease or other contaminants). That is the job of the flux. It will do two things usually - clean the metal in the first place (assemble joint with flux and twist it a bit to transfer it to all the contact surfaces), and keep it from oxidizing as you heat it. I would suggest something like a tub of Fry Metals "Powerflow" flux - this is slightly aggressive and will clean the metal well on contact.

One other thing to avoid is overheating the metal and boiling off all the flux. It should only take a few seconds of playing the flame over the joint to get an end feed fitting hot enough. If it is glowing red or giving a bright green flame you are overdoing it!

[Cicero]

============================ Just a minor point.

Clean and flux the pipe well beyond the ends of the fitting so that you can see clean fluxed pipe projecting outside the fitting.

It would also be worth checking that you're using the correct flux to match your solder. I believe that some newer lead-free solders and fluxes don't mix well with the older types. Perhaps someone will confirm or advise on this aspect.

Cic.

[Peter Andrews]

Are you cleaning the outside of the tube and the inside of the fitting with steel wool and then spinning it a half turn or so onto the cleaned and fluxed tube? If the solder doesn't flow then it's usually due to inadequate cleaning and fluxing.

Peter

[Mathew Newton]

A tip passed down from my father is to bend the solder at the half-inch point so then it's easy to see when you've applied the approximate intended amount.

Mathew

[John Rumm]

The newer lead free solders don't flow quite as well (although IME there is not much in it), and they don't look as bright and shiny once cooled.

The powerflow flux I suggested works well for both:

[Dave Plowman (News)]

That's a good tip.

[George Tingsley]

it could be that you are overheating the join and burning off the flux Try another test but don't let the flame come into contact with the join as in this picture

12 This takes longer to get the pipe up to the correct temp and makes it difficult to burn the flux Keep moving the flame away from the pipe and testing to see if the solder runs when touched on the fitting

[Chris Bacon]

Wipe off excess with a dry cloth. Having a damp cloth just makes it more likely that you'll get a burn (steam), and shock cooling is very bad for soldered joints.

Make sure your gas torch can heat the whole joint, one that's too small is difficult to use.

The latter sounds most likely. The metal could be over- or under hot.

Steel wool is good for cleaning tube. Wipe some flux around only where you want the solder to go, a fingertip is good, or a small brush. Unlike Mr. Rumm, I would absolutely avoid Fry's "Powerflow" and go for a better flux such as Laco:

One other thing to avoid is overheating the metal and boiling off all

Heat the tube first/slightly more, it's easy to overheat a little coupling or whatever, the tube takes a bit more. It's surprising how little heat you need.

[Dave Plowman (News)]

Certainly if you use a finger to apply it. ;-)

[Chris Bacon]

I've found "Powerflow" less "active" than Laco, but neither are particularly bad for skin (at normal temperatures!!!).

[Dave Plowman (News)]

Right. I've not used either but prefer active types. And they certainly don't do your skin any good.

[Lobster]

Well thanks again everyone! Still not able to do it reproducibly though. I've tried all the tips mentioned in this thread (most of which I was already doing TBH).

People keep talking about heating for a few secs; well it's taking me more like 1-1.5 minutes to get the joint up to enough temperature to melt the solder. And all that time the flux is boiling/burning off I think. But heated for less than that time, I push the solder against the pipe and it *just* melts, forming a blob which immediately solidifies without running up the fitting, because the pipework/fitting isn't hot enough. I'm using an ordinary butane cartridge blowlamp, with a brass burner approx 15mm diameter and which seems to give out a good blast of flame, and I'm using the hot part of the flame, not the blue unburnt area. Does this make any sense?

David

[John Rumm]

That rings alarm bells...

For a straight end feed fitting on 15mm pipe you should be able to complete the whole joint in 30 secs - probably quicker.

I find if you keep playing the heat on the pipe, there is a maximum delay of about 5 secs from the point at which the solder will just begin to melt to when it will flow freely.

(unlike electronics solder, plumbing solder is deliberately formulated to be non eutectic - so the transition from just molten to completely liquid is spread over a wide ish temperature range - hence the need to get the pipe hotter than just the threshold temperature at which the solder begins to melt)

Try another blowlamp[1]! It may be that yours is not focussed enough to heat the metal quickly. Your description of the flux boiling off does sound like it is the cause of your problems. Possibly try another flux or solder. Those are the only things I can think of since given the procedure you are carrying out, you ought to be making perfect joints every time without any difficulty! (Not wishing to demoralise you, but end feed fittings really are simple to use ;-)

[1]If you want a cheap one to try, a bog standard Wicks butane/propane mix one should do the job well enough...

[Chris Bacon]

There's something wrong with your blow-lamp, unless you're just wafting the flame around in the general vicinity of the work. Angle the blowlamp along the pipe a bit so that the flame heats more of it, don't go at 90 degrees to the pipe ("you're probably already doing this" :) ). You should see the flux start to bubble almost immediately, then see the cleaned copper, then the solder should flow. Are you practicing on microbore, 15mm, or ?

[Lobster]

mm, thought as much...

Well, it does seem odd. I'm not normally totally cack-handed with tasks like this! Just before I buy my new blowlamp - how far either side of the joint should I be heating? I'm playing the flame over an area about 1.5" either side of the fitting: could that be too much?

Thanks for the continued advice! TBH I'd have probably given up by now but for the fact that I can't buy the fittings I need in Yorkshire style (various 10mm 15mm stuff).

David