Vertical Boiler Fittings

[gary arthurParticipant @garyarthur48070]

Thanks Peter.

Now I'm anxious about the hydro test. Anxiety comes with the territory though…

Will post updates as it develops and will also be interested if you decide to start a thread on your build

[gary arthurParticipant @garyarthur48070]

BTW apologies for the terrible sound quality on the above video. I bought a cheap new video camera. False economy. Back to the Samsung Galaxy Tab for the next one!

[gary arthurParticipant @garyarthur48070]

Hi again…

here it is all set up and ready for pressure testing with water… tomorrow!

All I did afer taking this photo was to silver solder on the pipe unions.

Tomorrow will either be a good day or a bad day for me…

[gary arthurParticipant @garyarthur48070]

Well…. not the outcome that I was hoping for today.

During the initial air test at 15 psi a couple of weeks ago it was apparent that there was a small leak where one of the fire tubes joins the end plate at the top of the boiler. I mechanically expanded the end of the tube which seemed at the time to do the trick as the boiler held 15 psi of air after that.

Today, however, under hydraulic testing to 90 psi that leak has come back to haunt me. I suppose that given this is my first effort I should be a bit pleased that there appear to be no other problems. However, this leak has to go. Further attempts to mechanically swage the tube end (without heat) have only made the leak worse, and it is now dropping from 90 to 45 psi in 30 seconds. I could fiddle about with it more but I'm afraid of stressing the end of the tube. The photos below show the problem – it's the tube at bottom right, marked in blue. You can probably see the stress marks inside the end of the tube but fortunately there doesn't seem to be any leakage on the inside, just round the outside where it joins the end plate.

My thought is to try to deal with it by caulking it with a ring of low temperature silver solder round the outside of the tube. I used medium temperature silver solder initially on that part of the boiler so my hope is that if I can do it this way I might be able to avoid disturbing other joins which seem to be ok at the moment. I'm also thinking of using my small portable oxy-mapp torch (instead of the big bad boy) to keep the heat as local as possible.

Does this seem like a reasonable plan under the circumstances? Or do any of you good people out there know of a better way for me to tackle it?

Photos:

Thanks…

gary

Edited By gary.a.ayres on 26/06/2018 15:49:43

[julian atkinsParticipant @julianatkins58923]

Hi Gary,

The proper repair would be to thoroughly clean and flux generously all over and re-silversolder the leaking tube. This is not difficult to do on a boiler like yours, though expanding the tube is with hindsight is not the correct procedure, and you will probably not get a penetrating joint, but you should aim to form a generous fillet. A loop of copper wire around the protruding end of the tube might assist in this.

Cheers,

Julian

[gary arthurParticipant @garyarthur48070]

Julian – thanks for this.

Now I'm wishing I hadn't expanded the tube, but as you say hopefully a fillet will do the trick instead.

I did wonder about adding some copper, and will think about the wire idea.

All the Best,

gary

[duncan webster 1Participant @duncanwebster1]

Gary, I've sent you a pm

[gary arthurParticipant @garyarthur48070]

Thanks Duncan – will look now.

[gary arthurParticipant @garyarthur48070]

Thanks to you Duncan and some others on another forum, the leak appears to be fixed .

Will post again when I move on to the next stage…

Cheers.

[gary arthurParticipant @garyarthur48070]

Hi –

Following an experience with a leaky check valve during my first hydraulic test, I followed advice and took two remedial steps: replacing the steel ball in the check valve with a nitrile one, and adding a globe valve between the pump and the check valve. This really did the trick, and the result was version 2 of my test rig which has no leaks in the water feed system. When that globe valve is closed, it's closed! Photo below.

 

And now the bad news: the improved system showed clearly that what I had thought was a repair was an improvement, but not a repair. The offending tube still leaks, albeit more slowly. During the test, the pressure dropped from 90 psi to 78 psi over a 30 minute period – better than it was, but a leak nonetheless. The photo below (top left tube) shows the problem – there is a gap under the fillet which I added, probably due – I think – to insufficient heat during the attempted repair. My plan is to reheat it and try to melt the solder which is already in place so that it will flow around and into the joint more than it has. The boiler is now back in some new pickle for 24 hours to get it as clean as I can prior to reheating it, hopefully tomorrow evening. I will, of course, use plenty of flux and follow the previous advice on giving the whole thing an overall background heat with propane before focusing on the flaw with oxy/mapp.

However, if anyone has any other ideas I'd be happy to hear them.

Photo below:

gary

Edited By gary.a.ayres on 10/07/2018 22:43:26

[JasonBModerator @jasonb]

Yep lack of heat in the tubeplate, you have only got the end of the tube upto heat.

[gary arthurParticipant @garyarthur48070]

Thanks Jason.

Well, back at it, then. No other option!

Will probably grind back that overhang first, as per advice offered elsewhere.

Edited By gary.a.ayres on 11/07/2018 07:28:05

[Neil WyattModerator @neilwyatt]

You will find that once red hot, adding a bit of fresh silver solder will help the existing lump to melt.

Neil

[gary arthurParticipant @garyarthur48070]

Hi Neil –

Useful to know; thanks.

I'll grind it back first, then bear in mind what you say when I'm silver soldering.

gary

[gary arthurParticipant @garyarthur48070]

Well, for reasons which I can't quite figure out I had a struggle with my torches but somehow managed to get the joint looking good.

I *think* the boiler may now be intact but am unable to test it as I sheared off the end of my pressure gauge adaptor when I was tightening it! I'll have to make another one but am going away for a couple of weeks on Saturday so it may have to wait until I get back.

Frustration…!

[gary arthurParticipant @garyarthur48070]

At last!

Successful hydro test today! The boiler is now sorted.

Away for a couple of weeks then on to the next step, which I understand should be another hydraulic test at 1.5 WP with all fittings in situ.

Many thanks for your fantastic help so far – it is truly appreciated.

[gary arthurParticipant @garyarthur48070]

[gary arthurParticipant @garyarthur48070]

Following an initial cleanup with files, Scotch-Brite and steel wool:

gary

[gary arthurParticipant @garyarthur48070]

Hi –



progress has been slow as I've been away and the hot weather has distracted me from the workshop.



However, I have just taken the black paint off all my fittings with acetone in favour of an all-brass look, and have made a start with Loctite threadlocker. My first experience with the stuff, but it does inspire confidence I have to say.



One slight issue faces me before I can go on to the second hydro test: way back when I was silver soldering in my bushes, I left brass blanking plugs (connected by a steel strip) in the two water gauge bushes in an attempt to keep them parallel. In my inexperience I didn't realise that the brass would be prone to melt, but the plug in the top bush did so. I had to drill it out and for reasons I can't now remember I ended up having to drill and tap it 5/16 instead of 1/4. I then made a threaded sleeve to reduce it back down to 1/4. This seemed ok, but tonight the sleeve sheared when I was trying it out. The upshot is that I'll have to make another one. I'm not overly worried about this as I'm pretty sure that with the Loctite it will be fine, but it's all more time of course…



Will keep chipping away and will post significant developments.

[gary arthurParticipant @garyarthur48070]

BTW you guys have been very kind and I'd like to return the courtesy by reading some more of your threads about your own work. It doesn't seem too easy to search for threads by author (am I missing something?), so if any of you would like to post a link here to your own favourite threads or just name them so I can search for them I'd be very grateful.



Cheers,



gary

[JasonBModerator @jasonb]

You may be better with a Loctite pipe joint sealer rather than a thread locker, if nothing else it will be easier to take fittings off at a later date rather than risk leaving part in the threaded bush.

[gary arthurParticipant @garyarthur48070]

Thanks Jason.

It's Loctite 2400 'threadlocker' that I'm using. On the packet it says 'designed for the locking of threaded components which require disassembly with standard hand tools'.

Do you feel that a pipe joint sealer would still be better?

gary

[doubletopParticipant @doubletop]

Gary

Loctite 5770 is what you need

**LINK**

 

Pete

Edited By Doubletop on 08/08/2018 11:39:22

[gary arthurParticipant @garyarthur48070]

Thanks Pete – will look into this.

gary

[gary arthurParticipant @garyarthur48070]

Hi again Jason and Pete –

Loctite 5770 appears to be pretty much unavailable in the UK as far as I can see.

However, Loctite 577 does seem to be available. Here it is:

https://www.amazon.co.uk/Loctite-Thread-Sealant-Strength-Genuine/dp/B00XLPMOPK

It looks the same to me – maybe they just knocked the 0 off the end of the number…

Do you think this is the one?

Don't want to harrass you with silly or obvious questions but I'd rather make sure that I'm on the right track at this point than muck things up later.

Thanks,

gary

Edited By gary.a.ayres on 08/08/2018 23:29:58

Edited By gary.a.ayres on 08/08/2018 23:31:31

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