Copper pipe bending

[andrew winksParticipant @andrewwinks64215]

Hi All

A topic discussed in the past but worth a revisit, I need to bend 1/8" copper for lubricator plumbing to a steam inlet tee and 3/16" for feedwater supply for a 5" gauge locomotive.

i have read about filling the pipe with salt, melted solder, sand, etc but what is the most practical? Advice greatly and experience greatly appreciated. Andrew

[andrew winksParticipant @andrewwinks64215]

[Michael GilliganParticipant @michaelgilligan61133]

Posted by andrew winks on 09/03/2015 14:03:47:

Hi All

A topic discussed in the past but worth a revisit, I need to bend 1/8" copper for lubricator plumbing to a steam inlet tee and 3/16" for feedwater supply for a 5" gauge locomotive.

i have read about filling the pipe with salt, melted solder, sand, etc but what is the most practical? Advice greatly and experience greatly appreciated. Andrew

.

Don't use Solder! … You will never get it out.

The proper material: 'Cerrobend' or 'Wood's Metal' melts at about 70 deg. C.

MichaelG.

[Capstan SpeakingParticipant @capstanspeaking95294]

Small pipe benders are pretty cheap anyway.

If the pipe isn't really new then it would benefit from being annealed first.

[Nick GrantParticipant @nickgrant21535]

I have used salt before but that was for an espresso machine with huge tolerances for accuracy and not what id call engineering. It works but i doubt the wall thickness in the bend was consistent or anything

[Robert Knox 1Participant @robertknox1]

If you have access to back numbers of Model Engineers Workshop , the August 2010 edition, Mick Knights wrote an article about a Mini Pipe Bender which works well for 1/8" and 3/16" copper pipe, I made one and it does all that he claimed.

[MuzzerParticipant @muzzer]

Yes, 'Cerrobend' or 'Wood's Metal' aka "bend alloy" is pretty neat. You can embed a plastic object in it as it solidifies (how's that for a puzzle!) or just about a finger print but be aware that it contains cadmium, lead and bismuth if people are going to handle it.

Being more of a fool than a plumber, I've never actually used it for bending pipes but it sounds better than the other ideas.

[Trevor Drabble 1Participant @trevordrabble1]

My prefered method of bending small pipes is my twin handled mini pipe bender . It does 3 -4-6 mm o.d. pipes and I find it is much more repeatable than using my mini springs . Got mine from Cromwell Tools , part number KEN 5886080K.

[Mike HulmeParticipant @mikehulme12251]

I use "Resin W 8" from John Neale. It is a resin and melts at 70 deg C., and contains no Cadmium. It melts out of the bent tube with boiling water, and the tube walls don't collapse on 180 deg turns. (I make Irish bagpipes, and there are a lot of bends involved!)

Mike

[andrew winksParticipant @andrewwinks64215]

Great advice, all! I had guessed the salt and solder methods were a bit dodgy. Some of the 1/8" bends are very tight so I think the resin idea will probably suit that better than the pipe bender. I still would like a bender for the 3/16" pipe, however. Would there be a copy of the MEW, August 2010 article available in the forum somewhere?

Cheers, Andrew

[EmgeeParticipant @emgee]

Hi Mike Hulme, do yo have a link to John Neale so I can get some resin W8 ?

Emgee

[Kenneth LindemanParticipant @kennethlindeman32408]

Give this company a try They have a product called Polybend which is healthy to use http://www.bendalloy.co.uk/ and are will the sell small quantities.

[MuzzerParticipant @muzzer]

£15 for 500g inc P&P. Doesn't sound too bad.

[EmgeeParticipant @emgee]

Has anyone tried freezing soapy water in the pipe before making the bend ?

This was on 'How do they Do it' when bending tubes for musical instruments and showed no distortion from the round when bent.

Emgee

[RobboParticipant @robbo]

Andrew,

check your messages re mick knights article

[DMBParticipant @dmb]

Emgee,
Why soapy water?

[EmgeeParticipant @emgee]

Hi DMB

When bending the ice moves in the pipe so the soap acts as a lubricant to prevent galling the surface of the copper or brass tube.

[julian atkinsParticipant @julianatkins58923]

i think many of you make things far too complicated! ive done many awkward pipe bends on my miniature locos.

i bend the annealed tube between my knuckle joints. as soon as it gets 'tight' i re-anneal.

here's a pic of me doing same to much larger tube for the radiant superheaters for my 5"g current project

cheers,

julian

Edited By julian atkins on 12/03/2015 21:58:15

[DMBParticipant @dmb]

Hi Emgee,
Thanks for that, its a new one on me
I’ll give it a try.
Regards,
John.

[Neil WyattModerator @neilwyatt]

If you lot read your last MEW properly, you might have come across Field's Metal which is a safer version of Wood's Metal.

http://www.stop4stuff.com/fields-metal/

I tend to use finger bends like Julian. It can help to use a toolmakers clamp or vice jaws gently fixed over the bend (yes it is awkward) as if the pipe is stopped from spreading sideways it is very unlikely to kink.

Neil

[CirclipParticipant @circlip]

Don't matter what you fill the tube with if you're trying to bend it tighter than the minimum CLR permissible for a given pipe diameter/wall thickness for a given material, especially in toy sizes.

Regards Ian.

[EmgeeParticipant @emgee]

Hi Julian

Your bends look good but I consider them to be sweep bends which no doubt suits your purpose. I too make single bends in the fingers but when a tighter radius bend is needed I revert to a home made bender, especially useful for making multiple bends and sets in the same tube to exact dimensions. Even with machine bending it is as you say important to keep the tube annealed to prevent rippling or flattening.

Neil, we don't all subscribe to MEW so not aware of any article but thanks for the link to Fields Metals

Emgee

[Mark P.Participant @markp]

Saw these on flebay **LINK** I made a couple for myself, they work a treat you can get a very tight clean bend,better than the 2 handled benders also they work very close to the end.

Mark P.

[Neil WyattModerator @neilwyatt]

> we don't all subscribe to MEW

But now you know what you are missing!

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 13/03/2015 11:16:11:

… you might have come across Field's Metal which is a safer version of Wood's Metal.

.

For those interested in recipes: **LINK**

MichaelG.

[Author]

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