Can't keep copper from kinking for IC

[Justdrumin]

so I'm making a dual coil IC with 60' of 5/8" od copper I bought a while back on clearance. The first coil went without a hitch. Looks great....the second one not so much. I wanted them to go in opposite directions and what did I do?!? Make them going the same direction. So now I'm trying to reverse the outside coils direction. I'm bending it around my 5 gallon brew pot and there's a kink. Every time I try to bend it further...the kink gets worse. Any way to keep the coil going without having a gigantic kink in it? First pic is my beautiful first coil.

 

[Justdrumin]

Here's the kink.

 

[Bobby_M]

You only get one shot to bend copper out of the box. It's pre-annealed and ready to go. Once you bend it, you have work hardened it and it will only become soft again by heating it again. My recommendation is to leave the coil alone and find a way to deal with it. Why exactly did the coils need to go in opposite directions?

 

[Justdrumin]

And here's the whole thing.

 

[evanmars]

Bobby is right, but you can try to fill the tubing with salt.
That will help keep it from kinking, but being work hardened already, it might split.

 

[wapitiscat]

I crimp/plug one end and fill the tubing with sand. Then bend it around the form. The sand gives the tubing some support and reduces (if not eliminates) the kinks. After coiling just cut of the plugged/crimped ends with your tubing cutter and attach your fittings. Oh ... and empty the sand!

<EDIT> The salt suggestion post came in as I was typing. I guess you could just wash the salt out instead of shaking out sand.

Todd

 

[flars]

A bending tool might help. The tool looks like spring about 8 inches long. It is slid over the copper tubing. The length of the tool evens out the pressure of bending, over a greater distance, to help avoid kinking. Costs about $6 to $8.

 

[Justdrumin]

You only get one shot to bend copper out of the box. It's pre-annealed and ready to go. Once you bend it, you have work hardened it and it will only become soft again by heating it again. My recommendation is to leave the coil alone and find a way to deal with it. Why exactly did the coils need to go in opposite directions?

I was planning to join them at the top and bottom with t's with ridgid risers off the t's. So the two coils will be separate with the same inlet and outlet. If that makes sense.

That's not what I wanted to hear, but that makes complete sense. I thought about clamping it just after the kink to keep the stress off of the kink. Do you think that'll help?

 

[Justdrumin]

I crimp/plug one end and fill the tubing with sand. Then bend it around the form. The sand gives the tubing some support and reduces (if not eliminates) the kinks. After coiling just cut of the plugged/crimped ends with your tubing cutter and attach your fittings. Oh ... and empty the sand!

<EDIT> The salt suggestion post came in as I was typing. I guess you could just wash the salt out instead of shaking out sand.

Todd

I've heard of people doin this before. I may try that seein how sand is pretty darn cheap.

Edit: Any clue of how much I'll need? I can get a 50lb bag of play sand at HD for $4. I know I won't need 50 lb, but it's cheap. I'm sure salt will be a lil more, but much more convenient.

 

[johngaltsmotor]

Instead of sand you can do it for nearly free. Fill it with water and put it in the freezer (depending on the size of your current coils).
This is how many complex tubes were made before hydro-forming (especially brass musical instruments. The ice works just like the sand and is easier to get out.
Unfortunately the only way to fix your kink is to gently massage the tube with pliers or a set of dies to make it round again - but I'd leave this until you finish the rest or it is likely to kink there again because you'll never get it completely perfectly round again.

 

[Justdrumin]

Instead of sand you can do it for nearly free. Fill it with water and put it in the freezer (depending on the size of your current coils).
This is how many complex tubes were made before hydro-forming (especially brass musical instruments. The ice works just like the sand and is easier to get out.
Unfortunately the only way to fix your kink is to gently massage the tube with pliers or a set of dies to make it round again - but I'd leave this until you finish the rest or it is likely to kink there again because you'll never get it completely perfectly round again.

That's a great idea, but my freezer isn't big enough.

 

[Justdrumin]

I kinked the crap outta it. What if I cut the kink out cutting off about 4', bought a couple to join the two and just make a 50' chiller out of it instead? I do have a 17.5 gallon kettle. So it's not like a 50' chiller is out of the question.

 

[Bobby_M]

And here's the whole thing.

Don't feel too bad, but you're flexing the hell out of that tubing for no reason. If you flip the right hand coil over, you'd only be reorienting the the vertical arrangement of the coils and NOT trying to bend the tubing nearly 180 degrees.

 

[Justdrumin]

Don't feel too bad, but you're flexing the hell out of that tubing for no reason. If you flip the right hand coil over, you'd only be reorienting the the vertical arrangement of the coils and NOT trying to bend the tubing nearly 180 degrees.

Well...somehow I thought of something and it worked. I pulled the end on the top down the outside of the coil and pulled the bottom through the inside similar to turning a shirt inside out. It worked!! Now my coil is about 4' shorter, but it's kink free and going the right direction. I'll post a pic when it's done. Here's the original one I got my inspiration from though. The one on the left.

 

[Justdrumin]

Well here it is fellas. It worked out perfectly. The water runs in both coils simultaneously and exits simultaneously. I put GHT fittings on the input and output.

 

[wapitiscat]

I've heard of people doin this before. I may try that seein how sand is pretty darn cheap.

Edit: Any clue of how much I'll need? I can get a 50lb bag of play sand at HD for $4. I know I won't need 50 lb, but it's cheap. I'm sure salt will be a lil more, but much more convenient.

No idea. I usually have some around for other stuff. I'm sure some of the more math-y folks could do the calculation.