How to bend 1/4" pipe without kinking?

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Sluis Van Shipyards

Legendary Member
If it's brass, get the trick instrument makers use: fill pipe with soapy water, plug the 2 ends (rubber plug if possible) put pipe in freezer for 36 hours (to make sure all of your water is frozen solid), remove from freezer and bend it: voilà...a perfect bended tube with no kink!

I saw an episode of How It's Made and they were making a Trombone or Trumpet and that's exactly what they did. They froze the water and that keeps it from kinking.
 

Madhatter

Well-Known Member
I am going to give the freezing water trick a go tonight (or at least get it in the freezer for a couple of days) and see how that goes
 

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modelcitizen

Sr Member
not sure. my experience with the small brass tubing ended when my sand experiment failed. those other metals may work better but have to try.
might have to settle for a less extreme radius or maybe look in to an alternative like threaded fittings or such.
that's why i say let us know. some would never return to say if their tube bending projects worked or not.
 

sawduster

Well-Known Member
Hi everyone

I am going crazy trying to get 1/4 inch pipe to bend at a 90 degree angle without it crimping. I have tried a pipe bender, pipe bending springs,filling it with sand, heating it then try to bend it all of the above in one go and all with the same result: kinked bends. How can I get a 90 degree bend without the middle of the bend caving in on itself? I need to essentially make a U bend. It has to be a tube to run the power wires up through the middle

edit: forgot to mention it's brass tube Im trying to bend
The pipe bender you have should work You need to heat up your brass tubing first. Heat up the entire length you want to bend to red hot and let it cool down on its own, dont quench it, Once its cool then use your bender. Use firm constant presure and let the bender do it's job. Dont just squeeze it like your tighteing a pair of pliers. No need to put anything in the tube. The real trick is having a form to press the tube into. The form has to match the radius of the tubing. Ive made my own jigs from hardwood and rout a 1/4" radius into the jig, In this case you start the tubing at one end and press it into the form till you get to the end of your bend.
 

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Madhatter

Well-Known Member
Well, I am reporting back on the ice method - didn't work. The ice just cracked and got forced out the ends. I am thinking the radius is just too tight for the metal. However, after reading Sawduster's post, I realised I didn't heat it up enough to red hot, so maybe that's where I failed on that attempt, so I'll have a final crack at that. If it fails, then I will have to resort to a solid rod and shrink wrap the wires to the sides which is not preferable and it also means I won't be able to detach it from the base for transport.
 

sawduster

Well-Known Member
Well, I am reporting back on the ice method - didn't work. The ice just cracked and got forced out the ends. I am thinking the radius is just too tight for the metal. However, after reading Sawduster's post, I realised I didn't heat it up enough to red hot, so maybe that's where I failed on that attempt, so I'll have a final crack at that. If it fails, then I will have to resort to a solid rod and shrink wrap the wires to the sides which is not preferable and it also means I won't be able to detach it from the base for transport.
If it doesn’t work, can you show a sketch of what you’re trying to make?
 

Madhatter

Well-Known Member
Never too late! I am looking at a different metal and copper is on the list. It should be strong enough to support the finished model hopefully.
I haven't done the sketch yet but just imagine a flat bottomed U and you'll get the idea.
 

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