Bending 1/8" copper pipe

[CI]

There is a video on ytube of someone bending a long coil of copper tubing around a pipe, and he used the frozen water method.
The pipe was larger diameter, such as 1/2" or 3/4".
I suspect that the frozen water method would also work in small diameter tubing, but I have not personally tried it.

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[PaulR]

There is a video on ytube of someone bending a long coil of copper tubing around a pipe, and he used the frozen water method.
The pipe was larger diameter, such as 1/2" or 3/4".
I suspect that the frozen water method would also work in small diameter tubing, but I have not personally tried it.

Thanks, I might try it out on the offcut.

As it is I made a little former as per JCvdW's suggestion, stopping to anneal about 1/3 of the way through bending. After annealing the pipe was really soft (to be honest it felt too soft), in the end I doubt it was necessary given that it's new pipe and such a small diameter. The final result is good enough, there's just a little flattening at the curve and a small wobble I can remove with finger pressure latter but there's no interruption to air flow.

[gbritnell]

I just posted a response on HMEM. This is my bender

[gbritnell]

I posted the drawings on there also.

[RReid]

I have also made George's bender, and can vouch for its effectiveness when the "simple" solution is not good enough, i.e., larger diameter and/or harder to bend tubing.

[Kim]

There is a video on ytube of someone bending a long coil of copper tubing around a pipe, and he used the frozen water method.
The pipe was larger diameter, such as 1/2" or 3/4".
I suspect that the frozen water method would also work in small diameter tubing, but I have not personally tried it.

Thanks, I might try it out on the offcut.

As it is I made a little former as per JCvdW's suggestion, stopping to anneal about 1/3 of the way through bending. After annealing the pipe was really soft (to be honest it felt too soft), in the end I doubt it was necessary given that it's new pipe and such a small diameter. The final result is good enough, there's just a little flattening at the curve and a small wobble I can remove with finger pressure latter but there's no interruption to air flow.

Paul, in the Kozo method that has been posted here, he shows using a fairly snug fitting groove in his bending mandrel.  Vertical sides on the groove.  Part of the point of this is to hold the sides of the tube your bending so that they don't pooch out and make an oval.  It does help quite a bit.  I think your V shaped groove might have allowed the edges to bend out more than if they'd been vertical.   Also, the depth of the hole needs to be at least half the diameter of the tube you're bending.

I've used Kozo's method with good success.  Though George's bender is much nicer and I keep saying I'm going to make one someday!

Kim

[PaulR]

Paul, in the Kozo method that has been posted here, he shows using a fairly snug fitting groove in his bending mandrel.  Vertical sides on the groove.  Part of the point of this is to hold the sides of the tube your bending so that they don't pooch out and make an oval.  It does help quite a bit.  I think your V shaped groove might have allowed the edges to bend out more than if they'd been vertical.

I'm sure you're right about that - I used a HSS tool with a rounded end but it was clearly too v-shaped. In the early stages of making the groove it looked great but as I had to play it left and right to accommodate the width of the pipe the profile obviously changed. I'm not too worried as the pipe is mostly out of sight and at least air gets through. If I need to do it again I'll grind a better shaped tool 

[Dave Otto]

Thanks George, I have filed this one away.

Dave

[gbritnell]

When I built the fixture the first shoes, or whatever you call them,  were circular.   They had 2 faults.  The first ws not enough sidewall support and the second was when you would get to the end of the bend they would leave a depression in the tube. I changed to square shoes with a deeper slot. This kept the tube from flaring out and leaving a nice smooth transition at the end of the bend. The only hard part with using the fixture is calculating the amount the tube needs to be advanced for a second bend. You have to take into account the radius of the die.

[Charles Lamont]

George, I agree with you on the flat shoe. The only difference with my bender (post #7) is that the shoe rolls around the former so there is no rubbing contact with the tube.

[mklotz]

My version of this...

https://www.amazon.com/Tnisesm-Degree-Tubing-16-Inch-Diameter/dp/B0C7QM3TGJ/ref=sr_1_1?crid=C9BZFGMV0H0V&dib=eyJ2IjoiMSJ9.xxLeE8Pc0jRaaxKIT79Ny4eJQjfeMM44I0iGdrp7dXnjjpgN5Yo6sabat_JSrKWKZUi7r49pF8lhkbng8e-wNwHOT0piAACSHEdIgBFUuLB09TAa_tFGbe-KUWYysrGNGTiKtyxBgpfZhCYthyWA5_kCpBvdT7uM3F_rhjma64tLGOPNVxwDDvUnD15wRZNPtxJWLtNWnSNw9ISL_jtO-pSEarlY4ZUxH1K9P_kjpOPBgkbm_dtx41Bx4vcUtuaNKzLajvF_pbqgvarByJmZDsfDNEwU8y2C2f4aTU6SSG8.1pxjk4gDs4d26V6UbRLab620UEdEcBo9H4Fl-vq8wMo&dib_tag=se&keywords=miniature+pipe+bender&qid=1756405135&sprefix=miniature+pipe+bender%2Caps%2C196&sr=8-1

has worked well for my, admittedly infrequent, small pipe bending jobs.

[mike81]

Anneal first. Make a bending jig that is just a pulley with a 1/8" groove 1/8" deep. Make it from wood or metal. 1" diameter will  work.
You can fill the tube with sugar, plug each end. In order to make the sharp bend start with the tube much longer than you need. If you
feel resistance part way, stop and anneal again.

[PaulR]

Anneal first. Make a bending jig that is just a pulley with a 1/8" groove 1/8" deep. Make it from wood or metal. 1" diameter will  work.
You can fill the tube with sugar, plug each end. In order to make the sharp bend start with the tube much longer than you need. If you
feel resistance part way, stop and anneal again.

Thanks Mike, that's pretty much what I've done (except for the 'filling' ) but it seems the shape of the groove is important in getting the bend just right - something I've yet to perfect.

[tghs]

I use cerrobend (woods metal) to fill the pipe after annealing and before bending,, (doesn't cost much and can be used again and again) jin the asian steam ebay seller has a nice mini bender..
https://www.ebay.com/itm/232496785888?_skw=tubing+bender&itmmeta=01KM088KERSGYXBKJA3JW567AB&hash=item3621e369e0:g:TtcAAOSwqfpZxEim

[gbritnell]

With the bender that I presented you can change the radius of the bend bu making different size dies and shoes,  within reason. I have bent thin wall stainless tubing with no problem. At times I have used Cerro metal to help support the walls.