Bending 1/8" copper pipe

[PaulR]

I need to bend some right angles into 1/8" copper pipe but it's too small for my plumbing pipe bender and I don't want to buy another tool as it's not something I plan on doing regularly.

I've read about filling the pipe with water and washing up liquid and freezing it but I'm not sure that would work for this small bore. Has anyone tried it or can offer an alternative solution? Would any heat be needed during bending? It's new pipe, would it need annealing first?

(I've also read about buying soft plastic rod to fill the pipe but again I'd like to avoid the expense if possible.)

Cheers

Paul

[Jo]

I have some Woods metal which I use to fill the pipes when bending really small pipes. I would still make up a bending jig to make sure the bend was smooth.

Jo

[gbritnell]

I have a drawing to build a small bender which can be used from 1/8-5/16 tubing. Send me a PM  with your email address and I will send it to you

[Keith1500]

I would bend the pipe around something that’s the right diameter held in the vice. Anneal the copper pipe first and allow for a straight bit either side of the bend that can be trimmed back to suit. You’ll feel the pipe start to roll around the “guide” in the vice. Don’t allow it to bend in one place but roll along the circumference of the bend. Don’t do it in one hit either. The pipe will start to oval. At this point stop and anneal then in a small smooth jaw vice gentle squeeze the pipe round. Work in from the straight sections as these are still round. Then continue with the bending.

If the bend is slightly in the wrong place you can “ roll” the bend along a little by adding to the bend at one end and easing out or re straightening the other, again using the small vice and multiple squeezes to keep it round.

All the pipe work on my Speedy was done by hand and likewise brake pipes on my car.

1500 - this years (2009) cab by GL5Keith1500, on Flickr



Cheers
Keith

[tghs]

annealing is your friend along with woods metal (cerro bend) easy to turn a mandrel for the size you need.. I did get on of these a while back.. nice and small,  https://www.ebay.com/itm/232496785888?itmmeta=01K3GJNWGENKE88JM09WKZ3X1K&hash=item3621e369e0:g:TtcAAOSwqfpZxEim 

[PaulR]

I would bending the pipe around something that’s the right diameter help in the vice. Anneal the copper pipe first and allow for a straight bit either side of the bend that can be trimmed back to suit. You’ll feel the pipe start to roll around the “guide” in the vice. Don’t allow it to bend in one place but roll along the circumference of the bend. Don’t do it in one hit either. The pipe will start to oval. At this point stop and anneal then in a small smooth jaw vice gentle squeeze the pipe round. Work in from the straight sections as these are still round. Then continue with the bending.

If the bend is slightly in the wrong place you can “ roll” the bend along a little by adding to the bend at one end and easing out or re straightening the other, again using the small vice and multiple squeezes to keep it round.

All the pipe work on my Speedy was done by hand and likewise brake pipes on my car.

Thanks Keith, if I can get them to that standard I'll be more than happy. Need to get some random bits to practice on!

[PaulR]

annealing is your friend along with woods metal (cerro bend) easy to turn a mandrel for the size you need.. I did get on of these a while back.. nice and small,  https://www.ebay.com/itm/232496785888?itmmeta=01K3GJNWGENKE88JM09WKZ3X1K&hash=item3621e369e0:g:TtcAAOSwqfpZxEim 

Thanks for this - that bender is the mini version of my plumbing tool.

[Charles Lamont]

To my mind, a pipe bender for small tube that will do a good job needs three things: a die to form the bend around, an anchor to hold the fixed end as close to the die as possible, and a former. Rather than a wheel former, which can't be got close enough to the anchor piece without being cut away like the die, my former is straight, and is pushed round by a bearing.

[PaulR]

To my mind, a pipe bender for small tube that will do a good job needs three things: a die to form the bend around, an anchor to hold the fixed and as close to the die as possible, and a former. Rather than a wheel former, which can't be got close enough to the anchor piece without being cut away like the die, my former is straight, and is pushed round by a bearing.

That a very nice tool (but would probably take me longer to make than the entire engine  ). Still, it provides useful tips for doing it in a more ad hoc manner - thanks!

[vtsteam]

I need to bend some right angles into 1/8" copper pipe but it's too small for my plumbing pipe bender and I don't want to buy another tool as it's not something I plan on doing regularly.

I've read about filling the pipe with water and washing up liquid and freezing it but I'm not sure that would work for this small bore. Has anyone tried it or can offer an alternative solution? Would any heat be needed during bending? It's new pipe, would it need annealing first?

(I've also read about buying soft plastic rod to fill the pipe but again I'd like to avoid the expense if possible.)

Cheers

Paul

I've heard of using sand (in the case of 1/8" pipe, it would need to be fine sand) and then bending it.

The important part is that it must be capped at both ends so the sand can't move. Probably cap at one end, tap vertically on a hard surface to settle toward that end, top it up again and cap at the other end.

I would probably try it by simply squeezing the ends on 1/8" tube to cap them. Then cut off the crimped ends afterwards.

[PaulR]

I need to bend some right angles into 1/8" copper pipe but it's too small for my plumbing pipe bender and I don't want to buy another tool as it's not something I plan on doing regularly.

I've read about filling the pipe with water and washing up liquid and freezing it but I'm not sure that would work for this small bore. Has anyone tried it or can offer an alternative solution? Would any heat be needed during bending? It's new pipe, would it need annealing first?

(I've also read about buying soft plastic rod to fill the pipe but again I'd like to avoid the expense if possible.)

Cheers

Paul

I've heard of using sand (in the case of 1/8" pipe, it would need to be fine sand) and then bending it.

The important part is that it must be capped at both ends so the sand can't move. Probably cap at one end, tap vertically on a hard surface to settle toward that end, top it up again and cap at the other end.

I would probably try it by simply squeezing the ends on 1/8" tube to cap them. Then cut off the crimped ends afterwards.

Thanks for this, another option to consider. I've got some builder's sand knocking around but not sure if that would be fine enough - I'll have a look tomorrow.

[JCvdW]

In his book "The Pennsylvania A3 Switcher", Kozo Hiraoka discribes a way to bend thin copper tube. Here is a photo of the drawing in the book, that should be self explanatory. I have not used it myself yet...




 

[vtsteam]

Thanks for this, another option to consider. I've got some builder's sand knocking around but not sure if that would be fine enough - I'll have a look tomorrow.

For fine facing sand for casting, I have sifted it through a strainer in the past. Fineness depends on the mesh of your strainer. Cooking splash screens have quite fine mesh. Tea strainers also are good.

I'd probably bend it with a homemade form as others have suggested, maybe a grooved wooden dowel. The main assistance of the sand is to prevent kinking.

[RReid]

I've used something as simple as Kozo's suggestion to bend annealed 1/8" copper, as well as brass, tubing with perfectly satisfactory results.

[PaulR]

In his book "The Pennsylvania A3 Switcher", Kozo Hiraoka discribes a way to bend thin copper tube. Here is a photo of the drawing in the book, that should be self explanatory. I have not used it myself yet...

Thanks for this, that's almost what I was thinking of doing except in the horizontal plane. I'm pretty sure I made something like this diagram for bending pipe years ago: (a) and (b) tube and former fastened to plate, (c) moveable tube. But the method in your photo looks easier!

Thanks all for the replies, I'll be trying this out later.

[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.

.

[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.