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05-01-2006, 08:33 PM #1
I have some copper tubing 3/4" that I want to bend. I have a Greenlee model 1800 conduit/pipe bender. Im thinking the 1/2" pipe groove on the bender and 3/4" tubing is about the same size, so might work. Anybody know about this situation?
05-01-2006, 08:41 PM #2
Unless it is soft or annealed copper tubing you will have no luck bending. The tubing will buckel and collapse. Type L & K straight length water line won't work.
05-01-2006, 08:50 PM #3
No. That's why they sell elbows (pre-fab bends).
05-01-2006, 08:56 PM #4
Im talking about tubing here, not copper pipe. elbows are for pipe. I know copper tubing can be bent (It comes in a roll) but can it be bent with a conduit/pipe bender, since I dont have a 3/4" tubing bender laying around.
05-01-2006, 08:58 PM #5
A thinwall electrical bender works well for this. I have used it many times for a neater looking bend on soft copper AC lines rather than freeform hand bending.You need to lay the tubing on a hard floor and bend with downward pressure of your foot. Pulling the tube around with your hand will kink it. Hard copper can also be bent but you have to aneal it first. I use enough heat to darken the tube a bit beyound the bend.You can use a red heat but a thick oxide scale will form.For AC work a nitrogen purge will prevent the scale from forming on the inside.Plan to make a few practice bends.Some flatening of the tube is inevitable.
05-01-2006, 10:33 PM #6
yes, it can be bent. i had to do this a couple years ago and needed a special bend in copper tubing. tried bending on a conduit bender and although technically it bent, it was flattened out more than i cared for in the middle of the bend.sooo... i then cut a longer than neccassary piece of tubing and filled it with sand(fine ashtray sand is better b/c large grain sand will dent the tubing-if appearance is an issue)cap one end with a cap and solder on. fill slowly and keep tapping on bench or floor to make sand settle till it won't settle anymore and then solder on another cap. make your bend and cut off the ends to remove sand. this way the bends can usually be made by hand or the bender.
05-01-2006, 10:36 PM #7
This will be the discharge for an air compressor Im plumbing. A little flattening would be OK. A near collapse not ok.
05-02-2006, 12:29 AM #8
I work with type K copper all the time. When I want to bend it, I just grab onto it and bend it around my leg. Cut it a little long for leverage, make your bend, and then trim to sute. If you need to re-anneal, just heat with a propane torch (OA will work too) and let it cool slowly.
05-02-2006, 12:31 AM #9
I'm a little surprised to hear that I can't bend hard copper tubing ("pipe") with my bender, especially since I've done it many times. I can bend 1/2" copper pipe in my JD2 bender using a 5/8" die. I've done bends from a few degrees, up to > 90 degrees. The copper pipe does not collapse. It bends very nicely, actually; just like DOM but with much less effort.
- Glenn M.
05-02-2006, 12:34 AM #10
Well Glenn, now you know. Tomorrow you've got to go out and find a new way to do it
05-02-2006, 01:20 AM #11
Well, Flung Dung (or should that be "Dung Well Flung"?) I guess you are right.
Thinking about this, I wonder if there might be some confusion about what exactly is meant by a "bender." A conduit bender might collapse Cu pipe; I don't know about that. Never tried it. But a "real" tubing bender has a die and a shoe that support the tubing during bending.
I've successfully bent .049" wall 6061-T6 tubing in that die. That seems more likely to collapse than Cu pipe, but it wasn't a problem. There is very little flattening on the bend.
I've done the sand-bending routine for other jobs, too, but there is no need to pack the tubing if you are using type K copper. I haven't tried type L, but I imagine it would probably be OK, though type L is not recommended for compressed air according to the "Copper Development Organization."
There is lots of good info on working with copper pipe for compressed air and industrial applications here: copper tech ref
05-02-2006, 02:54 AM #12