Bending copper tubing

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I have some 3/8" copper tubing that I need to bend at a tight radius. Like 2". I have the spiral bender, and another hand held type, but can't find either. Next week, I gotta get organized. In the meantime what's the best way to bend it? I've heard of putting it full of sand. If I do that, do I bend it around something round, or just bend it slowly and cautiously?

Steve

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I have a similiar dilema. Refrigeration units that store salads and foods with high acid content, eat up the condensate line (condenser high side line that dissipates the drain water in a pan). The radius is like you say about two inches and all the benders I can find are larger radius than that. Oh and I need 180 degree bends to get as much surface area as possible. If I lose a complete pass, due to space, it will not get rid of the water and we now have a water leak to worry about. Harbor Freight has one that works........but mine leaves a pretty good scar on the tubing on a 180 degree bend, and all the others on the shelf look identical with no difference in quality. It seems the guide is too loose and crimps the tubing, For the money it is not bad. I am half tempted to fashion a bender out of some heavy wood using a 3/8" core box bit and woodworking router (cutting the flutes as deep as possible). Another posibility is to stack large flat washers between two flat pieces of steel and bend away. This may require dissasembly for each bend but get you out of a bind. Good luck and tell me what you came up with. Lyndell

----- Original Message -----

Newsgroups: rec.crafts.metalworking Sent: Saturday, October 08, 2011 9:35 PM Subject: Bending copper tubing

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"Lyndell Thompson" wrote in message

Newsgroups: rec.crafts.metalworking Sent: Saturday, October 08, 2011 9:35 PM Subject: Bending copper tubing

I have bent 3/8" and 1/4" copper tube to some tight radii by wrapping the area to be bent closely with small copper wire and bending by hand. Carefully.

Garrett Fulton

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Good idea, I will try it. I could leave the wire on it for extra protection and wear resistance. 14 guage solid wire?

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Steel wire will work better. Have you ever seen "spring benders"?

They're a little bit of a chore to get back off a tight bend, but they work very well. I have a nice full set in my refrigeration kit. Just expect to spend longer getting the bender back off the tubing than it took to put it on and make the bend. Spin the bender in a direction to UNwind the spring, and it will slowly screw itself off the tubing.

LLoyd

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On Sun, 09 Oct 2011 10:31:50 -0500, "Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote:

Or secure one end with lightly applied visegrips and unwind the spring enough to pull it right off. They're usually a PITA to use, though, and you can't use them on complete tubes, with flared connectors already installed. I have several handheld benders for those.

-- Never trouble another for what you can do for yourself. -- Thomas Jefferson

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So, don't flare the "U"s until you have them bent. This is a homebrew.

LLoyd

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On Sun, 09 Oct 2011 10:40:45 -0700, Larry Jaques

"open coil" benders can be used on already flared tubes, you justunwind the spring off the tube. Closed end coils CAN be used this way as well, but a lot harder to get the end started unwinding without damaging the spring.

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"Lyndell Thompson" wrote in message

Good idea, I will try it. I could leave the wire on it for extra protection and wear resistance. 14 guage solid wire?

I always used .040 stainless lockwire. Don't see why the 14 guage copper wouldn't work, but haven't tried it.

Garrett Fulton

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Garrett Fulton wrote:

Amateur radio types used to bend copper tubing by filling it with sand to keep it from collapsing while bending.

--
You can't have a sense of humor, if you have no sense.

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On Sun, 09 Oct 2011 11:21:54 -0400, Michael A. Terrell

I did some research on this question some months back when I wanted to wind copper and aluminum coils to power a "putt-putt" ("pop-pop") boat. "Spring coil" benders/winders are helpful up to a point (about 270deg), but with really tight turns it's hard to remove the spring coil from the finished tubing coil.

Through some oversight I actually saved the links to a couple of sources that I found useful:

Home Distiller: How to wind a perfect coil condenser http://homedistiller.org/forum/viewtopic.php?f=2&t 554

MetalGeek: How to Bend Tubing and Pipe by Hand http://metalgeek.com/archives/2005/05/01/000047.php

Hope these are helpful.

Frank McKenney

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not whether it has any evil in it; but whether it has more of
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On Sun, 9 Oct 2011 08:59:17 +0200, "Garrett Fulton"

You may want to make sure the tubing is fully annealed first too.

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I have tried the sand method and it did not work well for me. The classic way to make the sharp bends on trumpets and such is to fill the pipe with melted pitch and let cool. Another method is to fill with a water-detergent mixture and freeze it. The detergent keeps the ice from becoming hard enough to burst the pipe. Don't ask me what the right detergent concentration might be.

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anorton wrote:

probably find it in this

http://www.copper.org/publications/pub_list/pdf/copper_tube_handbook.pdf

--
Steve W.

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On Sat, 8 Oct 2011 23:50:36 -0700, "anorton"

How about filling with melted paraffin wax and then just melt it out after bending?

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On 09/10/2011 16:59, snipped-for-privacy@snyder.on.ca wrote:

I don't think that would be strong enough, I think it will just extrude and the pipe will flatten. Molten lead is another option; there used to be low melting point alloys specially for this (Cerrobend, in the UK). Non-trade name is Woods Metal.

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On Sun, 09 Oct 2011 20:46:47 +0100, Newshound

works just fine if you start with tube a bit longer than you need, fill 1t 100", and crimp both ends of the tube shut before bending. Also works best if the tube is at temp where the wax is still "Plastic" - not totally hard.

Full of grease works too, but it is a lot harder to clean out. Tallow would likely work too, and it never gets as hard as Paraffin. - again, perhaps not as easy to totally clean out??

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Fair enough if you have spare tube to play with.

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On Mon, 10 Oct 2011 20:38:47 +0100, Newshound

2 inches is a problem for you?

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wrote:

I saw the program where they were making trombones, they used the soap and water mixture there. I think sand has to be finer stuff than playground sand, probably more like some grades of molding sand. The classic production method for small tubing is Cerrobend as a filler, melts in hot water. Wall thickness will have a lot to do with how sharp a bend can be made, tubing is available in a lot of different wall thicknesses. And I'd definitely run the stuff through a torch to anneal it to dead soft before starting anything. Doesn't need to be red heat, just enough to discolor it. It DOES make a difference. Will probably take a number of tries before you get the right combination.

Stan

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