Bending small dia pipe

[Out2gtcha]

Here ya go:

 

It is standard K&S 1/8" brass tube (actually smaller than the 3mm Joe wants to bend). Probably not as tight a radius as Joe needs for his tank model, although I bent this with just my fingers. A simple pair of wooden dowels in a vice would yield a much tighter and more uniform curve. The sand used was regular beach sand (it is everywhere here), however it was not pounded - just loosely fillied the tube.

 

HTH,

D

 

Wow, I think that really is a great idea. Even better now that I know how well it works on pipe that size!

 

I just wish I had access to some beach sand....................not that I have a need to bend small dio tubing like this very often, but a great tip none the less, and one Ill definitely be adding to my arsenal.

 

Thanks!

[Heavens Eagle]

One other thing to remember is that most of the brass tubing is rather hard and stiff.  To anneal it, the brass needs to be heated untill it is cherry red to dull orange color then allow it to cool.  Then the sand trick would work even better.

 

When working with photo etch, there are sometimes parts that have to be formed to a curve.  When that part has a number of holes or even one hole, it will bend at the weakest point(s) first.  Annealing the part will soften it so that it is then easy to make conform.  It can even be possible to form the sheet to cupped shape, or in brass tubing to flare the end out.  Trying to do that with it hard would only cause the tubing to split.

 

A little more info than asked for, but food for thought which then gives options.

[LSP_Kevin]

I see a bent pipe ,  I did not see him do it.

 

Neither  did you , nor have you even tried to do it.

 

 But ,feel free to fill your boots.

 

It's a useful technique to bend tubes for scale models that D has proven to work. There's no requirement for engineering perfection here, and there's no one standing by ready to judge your pipe-bending symmetry. If it's a technique you prefer not to use, then don't use it. There are clearly other methods, so use what works for you. But pissing in other people's cornflakes just so you get to play the big shot is not on.

 

Kev

[D Bellis]

One other thing to remember is that most of the brass tubing is rather hard and stiff.  To anneal it, the brass needs to be heated untill it is cherry red to dull orange color then allow it to cool.  Then the sand trick would work even better.

 

When working with photo etch, there are sometimes parts that have to be formed to a curve.  When that part has a number of holes or even one hole, it will bend at the weakest point(s) first.  Annealing the part will soften it so that it is then easy to make conform.  It can even be possible to form the sheet to cupped shape, or in brass tubing to flare the end out.  Trying to do that with it hard would only cause the tubing to split.

 

A little more info than asked for, but food for thought which then gives options.

Good info, too. Although, I prefer to shock-cool metal being annealed by going straight from the glowing red stage to a submersion in cold water. The result is a very soft tube that can end up almost too soft. This shock-cooling can crack or shatter cast bronze or brass fittings if they're already attached to the tube, so avoid this method in those situations.

 

The tube shown in my post above was not annealed, though, and was still easy to bend.

 

Oh, and the beach sand that I used came from the edges of my lawn next to the paved driveway. As stated earlier, it is everywhere around here.

 

And, just for S&Gs, I tried using MicroBalloons as the sand medium for another bend, and that worked just as well - maybe even better.

 

Tinker with it and have fun. That IS the name of this game, after all.

 

D

Here ends the lesson...

[Out2gtcha]

And, just for S&Gs, I tried using MicroBalloons as the sand medium for another bend, and that worked just as well - maybe even better.

 

Now thats another cool trick....................I have a whole (nearly) brand new tub of MicroBalloons that I use readily for filling purposes. I might have to give that a whirl, as I have 0 beach sand available here, but a lot of MBs. + From what I have seen of the "playground" sand available here, the MBs seem MUCH finer.

 

Im thinking the fact that the MBs are so much more fine is the reason it might have worked better?

 

Ill def have to give that a go with the amount of that stuff I have around.

 

Thanks

[Zero77]

threading a flexible wire (copper, for instance) of the inside diameter of the tube may work, too.

[Heavens Eagle]

Only problem with the wire is that it most likely will become permanently caught by the tubing once it is bent.

 

As to sand "never" being used in tubing to prevent it collapsing, The 1965 film "The Flight of the Phoenix" has a scene where Dorfman is filling fuel line tubing with sand.  When asked what he is doing, he explanes that the sand will keep the line from collapsing when bent.

 

So a little movie trivia with the thread as well,  by the way are there any 1/32 C92 boxcar kits out there?  Vac or resin?

[Iain]

As to sand "never" being used in tubing to prevent it collapsing, The 1965 film "The Flight of the Phoenix" has a scene where Dorfman is filling fuel line tubing with sand.  When asked what he is doing, he explanes that the sand will keep the line from collapsing when bent.

 

Indeedy - and as far as I'm aware - a centuries old technique...

 

 

Iain

[LSP_Ron]

Indeedy - and as far as I'm aware - a centuries old technique...

 

 

Iain

 

Correct, it is.

[Ian M]

You can buy a special metal alloy that melts at waters boiling point. You can fill any size tube (or any section. square, triangle hexa.) bend the hell out of it, then just warm it up in a pan of water and pour the alloy out.

 

Cheaper way is to fill it with water, crimp the ends and pop it in the freezer....

[dmthamade]

Small diameter tube i've been able to bend smoothly without kinks by inserting Evergreen rod stock and bending over round stock. Stretched sprue also works. You can usually remove the plastic after the bending.

 

Don

[Bill_S]

Any finely divided solid should work as well as sand, too. Table salt or finely ground black pepper fit the bill.

Edited November 19, 2014 by Bill_S

[Smokeyforgothispassword]

I've used line trimmer line in the past as an insert, it worked well enough to make fuel lines for my r/c aircraft.

[LSP_Kevin]

I've used line trimmer line in the past as an insert, it worked well enough to make fuel lines for my r/c aircraft.

 

What a great idea! Does the line have to be a close fit inside the tubing?

 

Kev

[wunwinglow]

Be careful using those very low melt alloys, they have metals such as cadmium and bismuth in them, so are extremely toxic if ingested. But they are extremely useful too!,

 

Tim

 

Woods metal, also called Cerrobend, melts at 70 degrees Centigrade ( not sure what that is in old fashioned Imperialist Tyrant George 'Mad as a Frog' the Third units....)