Bend copper tubing w/o salt?

[sunshine4me]

I have seen the method of bending a tube by packing it with salt so it does not crinkle. However, I have seen it done on here without salt for 1/4" tubing. My question is, when does copper tubing require being packed with salt? Moreover, does my 1/2" copper tubing need to be filled with salt in order to get a smooth bend?

[HolyBear]

You can fill with water if you seal the ends. Water doesnt compress. Sealing the ends while full of water is the trick...

[Hawk eye]

They make a spring that slides over the tube that works very well and they are cheap

[wv_hillbilly]

I've bent 5/8 without salt, it was a bitch though.

[oliver90owner]

The usual, without a pipe-bender is the internal spring. Rather depends on whether this is a single direction change or a coil, as the internal springs are of limited length.

I'll take a guess - this is for a coil?

[buddha52]

I've bent 5/8 without salt, it was a bitch though.

+1

[Bushman]

I've made a lot of coils, with just about every technique that has been mentioned on the site. Doing it using Hooklines method without salt works but takes a lot of patients and you have to turn it slowly. When I use this method I have done it without kinks but have a slight flattening this still works great but I think the water flow is slightly restricted from what I've tested. Filling it with water is the easiest to clean but if you get the slightest air pocket then your going to have trouble. Salt works great but is a PITA to clean out. The method I have had the best success with is a real fine silica sand used for sandblasting. After I am done I just hook up my compressor and blow air through, takes about 10 minutes. For me this method was by far the least likely to have a problem.

I have not tried anything over 3/8" but have probably made over a dozen coils mostly 1/4" with at least 3 at 3/8". I have an idea for triple wound coil with a cold finger I think would work in a 4" column but haven't found the time to build it.

[Black Eye]

the bigger the diameter tube you bend, the bigger the bend radius needs to be to avoid kinking or filling with sand,salt, water. Wall thickness is a big factor too. Copper being a lot softer than most tubing materials throws another curveball at you. Usually I start with the 3:1 factor and see where that gets me. So I'd use a 1 1/2" diamter mandrel for a 1/2 tube as see what I get.

I've made a lot of jigs out in the shop for bending different tubing. Fine sand works really well for bending tight radii with out kinking especially if you're going to heat the pipes before/during the bend.

[ethanol+]

If you want to bend with out salt try using a water and soap mixture. I don't know the exact ratio of soap to water but its a lot of soap. my best guess is 60/40 water to soap. fill your copper tubing with the mixture and than freeze it. bend away

[winestill]

I submerged my 1/4" worm in water and it didn't kink.
Just compressed the ends and bent it.

http://homedistiller.org/forum/viewtopi ... 32&t=29342

[12bolts]

You can fill with water if you seal the ends. Water doesnt compress. Sealing the ends while full of water is the trick...

But wouldnt the water just displace if you dont freeze it?

Cheers Phil

[Tokoroa_Shiner]

As long as it is completely full, there would be no where for it to go

[Tal]

Sugar works too, easy to dissolve out when you're finished.....

[Dustydes]

Just finished my first condenser coil using salt method.
I had to anneal the 6mm pipe to bend around the 15mm mandril but for return on the 35mm pipe, anneal wasn't needed.
The return coil on 35mm gave me a finished coil of 50mm my Boka will be 54mm so a bit of clearance.
I had no flattening of pipe
After pic I cleaned with salt and lemon juice, works great

[/url][/img]

[rad14701]

Looks good, Dustydes, but the air gaps between coils is a bit wide and that will reduce efficiency to a minor extent... Air gap should be held to the same as the copper diameter, at most, but I prefer them a bit closer than that even... I shoot for half the diameter of the copper for air gap... Let us know how well your functions...

[Dustydes]

Thanks rad

Was hoping someone would get back on this.
I still have plenty of pipe still on coil as I haven't cut it down to size yet so I can close coils and wind more to make up to length.

Job done had enough to tighten coils to just under 6mm gap and give me an 8" coil for my planed 2" Boka

[stevenun]

I wound a 1/4" tubing coil around a 1 gallon paint can, using about 15 feet of tubing. If you go slow and easy and bend it around a form like another can, it's less likely to kink. I built three wood slats with holes in them to hold the spacing right. The whole thing sits in a five gallon plastic bucket. Works nicely but I know I need a bigger diameter coil from reading this site. I've gone through two of the five gallon buckets, they keep developing cracks and leaks. I'm thinking of trying a Liebig instead, but a nice 3/8" coil in a worm bucket just seems easier to me. No water pumps and extra hoses...

[groggx]

Just a curious thought. Would Baking soda work in place of salt, sand or sugar. It would be easy to remove. If it plugged a little vinegar soak would help remove it. Or would it not have enough space to compress in order to allow the tube to bend with out buckling? I know it is a old post just hoping to get an insight on the idea.

[still_stirrin]

....Would Baking soda work in place of salt, sand or sugar....

Baking soda (sodium bicarbonate) is a fine powder, not a crystal like salt, sand, or sugar. I would anticipate it to "bridge" and pack when filling the tube. Unlike the crystals which will slide into the tube easier. Filling a tube is still a pain in the (neck), but tapping on the tubing (vibration) helps to keep the crystals moving.

You can try the soda and report you success (or otherwise). But I recommend using salt...it can be washed out too, just not as easily.
ss

[Danespirit]

+1 Still stirrin..
Larger tubing can be bend with salt in them, for a refluxcondenser however, it's not necessary.
Se two of mine here: http://homedistiller.org/forum/viewtopi ... 87&t=52290
Bend without anything else than a vice, a pipe and my hands.
I can easily bend 1/4" pipe the same way..

Edit: Do not use sugar! The moment you heat it, you got caramel in your tube. Salt can disolve in water. Fine sand in larger tubes is ok.

[frodo]

with 1/2'' copper tubing. there are 2 types. hard drawn and soft copper

the hard drawn is in stick form,,,it is a total bitch to bend

soft copper is much easier to work...try anealing the copper as you work it

below,,is 1/2'' copper i wound around a bucket while heating it...no kinks