I've been doing a lot of copper plumbing lately and have got quite proficient at bending pipes using my pipe bender.
I have to run a 15mm pipe from floor to ceiling, and the wall is half tiled. Therefore the pipe needs to accommodate the change in surface depth (about 12mm) I think, as neatly as possible.
What's the easiest way of getting a close together "double-bend", or "step" in the pipe? I have a bending spring, and a pipe bender, but am not sure how to get the required two bends right next to each other.
Depends how tight you want to follow the step. You can get passover bends that you could solder on. I just put in two slight bends with a spring, but the gap between them was a hands-width so I could grip the "other" side of the second bend. There are instructional videos on the net - google for passover bend tuition or something. Simon.
Make up two sections of pipe with the required angles (45 degrees) and cut off one end of each pipe as short as possible. Make sure the 'stub' is straight enough to accept a straight end feed connector. Join the two short ends with a straight end feed connector.
FYI, this bend would be called an "offset" or, informally a "dog-leg".
formatting link
you plug the numbers in, you get a distance between bends of 24mm, which is virtually one flowing into the other. See:
formatting link
you will struggle to get a 12mm offset dogleg into a 15mm pipe.
Better to put a 45 degree bend in the pipe and then use a 45 degree elbow to do the other part of the dogleg, but you may find that you still can't get your offset down to 12mm.
Another option would be to not bend the pipe, but to use low-profile clips on the tiled area and standoff clips on the non-tiled area.
formatting link
items 8729 and 6478.
Another option would be to use a 45deg elbow and a 45 deg street elbow. Again, this likely would not give you an offset as low as 12mm.
Have you considered coming in gently over a slightly longer run? First bend of a few degrees at the tile boundary. Second bend of a few degrees a bit further down when the pipe has come in the required 12mm. It may well look less obtrusive than a sharper bend.
I'd have a go at two pulled bends it would look so much nicer. Example 3 in the above shows a 50mm "step" in 15mm pipe using 30 degree bends. I suspect the "23mm back" will be in the first pulled bend but I don't think that will be a problem.
Just had a quick 'n dirty play with some short offcuts. Managed to get a 15mm offset with two bends of about 15 degrees, the inside of the first bend is under the hook of the bender when pulling the second and the offset takes about 50mm to happen. Done with care rather than a rushed "bung a bit of pipe in the bender and pull it"(*) should be possible to pull double bend with the required 12 or
15mm offset.
(*) I actually did two, the first I didn't check that the pipe was inline with the former of the bender for the second bend so although I got the offset about right it wasn't flat.
Practice. I've managed to do what you describe several times just using a bending spring and my knee. It's easy if you are just doing one tube. If you need two identical ones (hot/cold or flow/return) then it gets a bit tricky and you need a good eye and the ability to apply controlled strength.
After you've buggered it up a few times you get the hang of it.
Of course the difficult bit is getting both bends in the same plane.
The trick there is to plan it using one of the web guides on dog leg pulling which give an idea of where to start pulling each bend based on the radius of your pipe bender former, assuming a pipe bender is being used.
I've used some scrap copper to "calibrate" mine:
I have a mark in "Sharpie" ink on the former where the bend will start and a number of marks (relative to a convenient fixed point on the other moving part of the bender) of how far to pull for 22.5, 30, 45, 60, 67.5 and 90 degrees. It's not absolutely repeatable (cheap bender) but minor discrepencies can be tweaked around the knee without a spring (we're only talking a couple of degrees tweaking either way - much more and you wreck the pipe).
If you are in a position to mark up the pipes with ink first and put some marks on the former wheel, then it's possible to mark up two pipes the same whilst straight.
That makes it fairly easy to get two identically bent pipes.
The harder bit I find is actually pulling the bends in to do what you want!
But if you can set up the job so that major tweaks can be achieved by rotating the piece and cutting to length, the ability to bend precisely becomes less important. Can't always be avoided, but a bit of careful though sometimes finds a cheat.
Re: taps - if the object is to offset the pipe so it comes back towards the wall, then use the same bend to bring the pipe more to the centre of the basin too (ie 45 degrees +/- looking down from the top menaing a bigger step in the dog leg than originally intended).
Basically this means that if you are out, you just swivel the pipe around until it suits the clips spacing from the wall. It might not land on the vertical axis you intended, but with both pipes bent the same, the result will be symmetrical and thus look perfect :)
I've buggered up several metres of pipe practising! I did manage to get my chrome right (with the cheat methods) though - didn't fancy wasting that!
Indeed. You have to do it by eye - though a bit of brute force with bare hands can usually tweak it afterwards if it is basically right.
The OP wants to get the bends 'close together' with an offset of just
12mm. He doesn't say what he means by 'close together' but his intention is to accommodate the step from a tiled section of wall to a section of wall without tiles. This will require the distance between the bends (according to my sample) to be about 2" maximum which might not be achievable in a single piece of pipe unless the bender former is a very small diameter.
See my earlier replies for my method which avoids the difficulty of getting the bends in the same plane in a single piece of pipe.
A quick play earlier with some scrap and standard pipe bender gave about 2" between two 15 degreeish bends and about a 15mm offset. That was a very quick 'n dirty play, with a bit of care I think one could produce a very acceptable result and smaller offset. It would look a lot better than anything with fittings involved.
Thank you to all for taking the time to reply in such detail, and thanks for an interesting discussion.
I should have said I needed to make two such bends for flow and return, and routing the pipe differently is not really an option.
I deliberated over the best method, and almost bought myself a bag of
25 45 degree end feed connectors from Screwfix (there is a branch near here), but in the end I used my pipe bender, and simply spaced out the two bends a bit more than I would have liked. This achieved the 13mm ish step over a distance of approx 2.5cm, not too far away from Dave's figures above. I did have to be careful that the "pipe clamp" (I think that's what it's called, the sort of hook device that holds the pipe steady in the bender) didn't dig into the reverse bend, but I protected the pipe with a bit of rag which allowed me to get the two bends closer together than would otherwise have been possible.
It did need some manual tweaking to get the two pipes to match, but that was no problem.
I have to admit I've never been much good with a bending spring (seems to need superhuman strength to get the pipe even to move, let alone form it to a precise bend!). Maybe I just need more practice on longer pieces of copper so I can get more leverage!
I tried to repeat your test with my pipe bender (Clarke - dual 15mm /
22mm) and got the same result as you got so it is certainly possible. Two inches seems to be the smallest practical distance possible between the bends without risking damage to the first bend by the tube stop. In fact it isn't the size of the former (as I thought incorrectly) that limits the offset size but how well one can measure the small angles involved on a standard bender which is not a very precise tool.
I suppose would could have a specially designed bender with more precise design and positioning of the tube stop to create these small close doglegs but it would probably have very limited use and cost more than a standard bender.
You must be a bit of a perfectionist to worry about the use of a single end feed fitting which is only about 2mm more than the diameter of the tube itself and barely visible when painted.
Nope, not only you. Bending springs used to work well when the standard copper pipe was thick walled (1.2mm) and fully annealed - then it was fairly easy to get decent results that way. These days the pipe is what is called "half hard" and thin walled (0.8mm), and that is not as easy to do with a spring.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.