Forming/bending 3/32 od copper tube.

[Brian AbbottParticipant @brianabbott67793]

Hello all,

Need some advice, I need to bend the pipe which connects the gauge to the boiler on my Minnie. Ideally I don't want to have to make a former for this one off job, anyone know any tricks?

Thanks,

[Brian AbbottParticipant @brianabbott67793]

[Jeff DaymanParticipant @jeffdayman43397]

1. fill the tube with low melt point alloy (cerrobend, Woods metal etc), bend as you would bend wire/rod, then boil tube to melt out alloy. Sometimes a rubber tube is handy to mouth-blow the last bits out. Do be very careful not to inhale or suck on the rubber tube- the metal is toxic (and hot if it has been in boiling water).

2. Find a close fitting steel spring that fits over the tubing. It may support it against kinks during bending well enough. In my experience for small diameters under say 1/4" this method sometimes does not work so well.

3. Make some wood or aluminum radiused formers for your vise and pull the tube around them. Formers for this method need to have oversized cheek pieces on both sides of the central radiused piece which in thickness should be only a few thou over the tube size to be bent. With the vise supporting the cheek pieces well I have had some succes with this method, but it gets tricky if there are bends in many different planes especially those close together.

4. Make a proper ME tube bender to one of the designs published over the years in the magazine.

Good luck. JD

[julian atkinsParticipant @julianatkins58923]

Hi Brian,

Anneal, bend between finger joints, anneal again if required. The fingers provide excellent sensitivity when more annealing may be required.

Some where in my albums is a pic of me doing this with 1/4" dia copper tube for the superheater tails on my latest 5"g loco.

Cheers,

Julian

[pgk pgkParticipant @pgkpgk17461]

I haven't tried it but came across the idea of plugging one end to fill and freeze full of ice before making the bend

[JasonBModerator @jasonb]

As Julian says its easy enough to do between fingers or round a bit of spare rod once annealed. at 3/32" OD the ratio of wall thickness to bore is high so there is no need to fill the tube.

[Brian AbbottParticipant @brianabbott67793]

Thanks all for your reply's.

I think i will try Julian's idea firstly, see how that pans out.

Thanks

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