Closing copper pipe ends

[Mark P.Participant @markp]

I have been asked to close the ends of some 15mm copper pipe with a dome, like a fool I said yes. I have tried forming a dome in the lathe by pushing it over using the top & cross slide with a steel block on the tool post, it was semi succesful but not right ie. not a dome. Should I be looking at making some sort of press tool? Any thoughts or sugestions welcome.

Regards Mark P.

[Mark P.Participant @markp]

[JasonBModerator @jasonb]

Buy 4503 & 4507 issues of ME, two ways of forming domes in there.

[Jon GibbsParticipant @jongibbs59756]

I've never tried this but how about creating a silver steel cold forming die with an 18mm hemispherical depression in one half and a 15mm dome on the end of a cylindrical punch and walloping an end-feed Yorkshire pipe fitting with a FBH.

You could then solder it onto the end of your pipe?

Jon

[Mark P.Participant @markp]

I will ask the chap if caps are acceptable, I did mention to him about making brass domes and silver soldering them on but he wasn’t keen. I believe he is wanting to build some sort of solar water heating panel for his house. Will have a look at the 2 ME issues.
The tubes will be 1.4m long.
Regards Mark P.

[Jesse Hancock 1Participant @jessehancock1]

Once again the mind boggles… Why domes??? Mark he may have got the terminology wrong and meant caps. If he argues give him the job back. Not worth the hassle. Mean time I have made a few using using a ball-pein hammer to form them. They were shallow though for HMS Kent ventilators.

[Nick_GParticipant @nick_g]

.

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Nick

[Ady1Participant @ady1]

One word for squishing the end of pipes etc is swaging

Might be worth a search

 

Edited By Ady1 on 12/05/2015 14:24:23

[Stuart BridgerParticipant @stuartbridger82290]

what's wrong with a 15mm solder or push fit stop end?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Stuart Bridger on 12/05/2015 14:25:59:

what's wrong with a 15mm solder or push fit stop end?

.

They are not [usually] domed

MichaelG.

Edited By Michael Gilligan on 12/05/2015 15:54:51

[Tim StevensParticipant @timstevens64731]

It is a simple matter to dome the end of a plain solder-on end cap. You need a dome block or a block (wood, MDF, Acetyl) with a hollow of about 17mm dia – not too difficult to make – and a punch (again wood or acetyl or nylon) domed at one end and a sliding fit in the fitting (ie 15mm). A couple of fairly gentle taps should be enough. If the caps prove to be too hard, heat to redness and cool down again, and they will be almost as soft as lead.

I suggest that if the requirement is to have domes which are integral, ie no thin flange where they are attached, you show him a picture of a gum tree and ask him what it is like up there.

cheers, Tim

[James AlfordParticipant @jamesalford67616]

Does the dome need to be solid copper or can the end have a small fill of braze in it? I made a simple set of jaws to form the domed ends on some pipe to make some bull rushes. I will post some pictures of the tool later this evening.along with a picture of the shape formed.

James.

[John HinkleyParticipant @johnhinkley26699]

Might as well have my two pennyworth. I would take a piece of 15mm copper rod (if such as beast exists), form a dome on one end with a ball-turner, form tool or file. Turn it around and turn t'other end to the inside diameter of the pipe. Pop it in the end of the pipe and add solder. Robert is your mother''s brother!

John

[Brian WoodParticipant @brianwood45127]

Mark,

If I may add a few comments.

Solar applications, if this is the intended use, can actually reach temperatures above the boiling point of water, depending on the system in use and coolant make up..

Panels made up of evacuated tubes with heat pipes inside can indeed, if boiled dry, get up to the melting point of soft solder and professional units with manifolds into which the tubes are plugged are all brazed units for that reason.

Plain end feed caps brazed on would be my recommendation if you plan to go ahead with the request

Brian

[Mark P.Participant @markp]

Thanks for the replys, still waiting for him to get back to me. I think that it will be more trouble than it’s worth. Would be ok if I was doing for myself!
Regards Mark P.

[James AlfordParticipant @jamesalford67616]

Following on from my earlier post, here are the pictures of the swaging tool and the resulting shapes. The tool was made from scrap, beig shaped with a dremel. The copper was repeatedly annealed, inserted into the jaws and the tool hammered shut whilst rotating the pipe. Working down through the holes allows fine control over the shape, leaving just a fine hole to braze shut. The bull rush shown flares back up at the end, but this can be avoided by simply going down through the sizes further.

Regards,

James.

 

Edited By James Alford on 12/05/2015 20:32:16

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