Thread: Bending S.S.Tubing

Originally Posted by ptrott

Hi all. (My first post on the metal forum)
My father-in-law has asked me to find out how to bend 12mm (.5") SS tubing, a 6 metre length into a coil about 400mm diam.
He's a wog who grows grapes and makes nice drinks, sorry, Experimental Alternative Fuels (which taste nice) with the juice so you know what it is for.
I was wondering if it could be done using a plumbers .5' copper pipe bender moving it along a little at a time and putting a few degrees onto it each time?
It would probably be extremely stiff (haven't seen it yet so not sure of the wall thickness) and likely to split or crimp.
The local steel place wants $100 to do it so I don't mind spending a bit of time on it.
There are a lot of st***s out there so it must be dooable. Any suggestions greatly appreciated.
Thanks,
Phill.

G'Day Phill,
I'm not an expert or have a trade in the metal industry, but I have worked in the chemical industry for 21 years and when bends where put in a tube/pipe it was mig'ed in. Anything like you are talking about was "sent out" to a specialist fabricator, and was done well. I am inclined to think you may break a standard copper tube bender, even hard drawn copper tube has to be annealed (softend) to be bent, else it flattens and/or splits. Stainless steel has, I would imagine a much higher tensile strength than hard drawn copper tube, you could try heating it but I think it would be more trouble than it's worth, if it was me in your place, I'd pay the $100 and get it done properly.
savage(Eric)

I have seen it done a long time ago, the manufacture of a home made pulpit for a boat.
The bloke who did it, a qualified fitter, filled the tube with sand, heated it and bent it round a wooden form. It didn't kink, but it did flatten, and it discoloured very badly.

Have heard that filling it with fine sand then driving a plug in each end so the sand is nice and tight will stop it crushing.:confused:

They make machines that do this but for the home job you can make several jigs from wood. Turn on a late a block of wood the diameter you desire and then turn a concave half round a little larger than the tubing. No play just a non stick fit. Make a block of wood with the same concave dia. You can then attach it with a flat steel bar. find the center of the round and drill a whole. You bolt the bar through the hole and the block on the outer edge of the round. It will end up being a wood tube bender. You might need to take the round piece and cut a tapered notch on the upper side. This will let the tube coil up. I have done it and not made any flat spots on the tube. 6 meters is very long. you might need to do it insections and use a copper streight conection. Hope this helps. Thin wall tube should work very sell for a still.

Thanks for the ideas gents. I might have to try the sand idea as I don't have a lathe big enough for a 400mm circle of wood. That sounds like a great idea for smaller circles though. I might have a quick look at the local junk yard to see if I can find an old "A" or "B" section pulley about 400 Diam, and make the draw-around block from wood.

Thanks again,
Phill.

Originally Posted by sailingamerican

They make machines that do this but for the home job you can make several jigs from wood. Turn on a late a block of wood the diameter you desire and then turn a concave half round a little larger than the tubing. No play just a non stick fit. Make a block of wood with the same concave dia. You can then attach it with a flat steel bar. find the center of the round and drill a whole. You bolt the bar through the hole and the block on the outer edge of the round. It will end up being a wood tube bender. You might need to take the round piece and cut a tapered notch on the upper side. This will let the tube coil up. I have done it and not made any flat spots on the tube. 6 meters is very long. you might need to do it insections and use a copper streight conection. Hope this helps. Thin wall tube should work very sell for a still.

Hang on!!!!!
Where is the " My wife is an Ozzie" thing??
Did you forget??

Al :confused:

I seriously doubt you'll be able to satisfactorily bend SS tubing with any of the above methods. Worked in a boatbuilding yard on and off for about ten years and even aluminium didn't always come out very pretty in a hydraulic pipe bender. The machines they use to bend ss pipe actually draw a ball theough the pipe as it is bent so that it won't deform.

Mick

Hey Al, leave SA alone! We'll have a demarcation dispute on our hands. Historically speaking it's the unalienable right of a certain chippy to bait him!

Mick's got it right as far as the perfect bend goes, you need a specialized machine
You could try a brewing shop they will carry the tubing already formed
Beware of heating the tube too much to bend it as you will get a scale form inside and then need to pickel it to get it all out



Rgds


Ashore

Hi Phil,
Having bent all sizes of copper tube using sand and the pipe benders ,my suggestion to you would be pay the $100 and have it bent otherwise if you stuff it up you will have to buy more tube and then get it bent professionally .
Ron

just makje the still with annealed copper tube

I will try the brewing supply shop first just in case. Failing that it sounds like a hundred bucks. That would be a rip-off unless the machine costs many many thousands. I guess they gotta pay for it somehow.
The copper tube is what he has been using and it leaves a bad taste. No good at all.
Intetesting thing...dragging a ball through it while bending. They must have a lot of different sized balls

Thanks gents.

Phil,
interesting comment you made about the taste with the copper. I have read several very reputable sources say that a bit a copper incorporated is a good thing. Also I am curious of the design if you need a tubing setup like that. PM me if you want some designs that are easy to make and use.

Rowan,
Did you get my PM?
I would be interested in those designs. Anything easier that works is better

Originally Posted by Wood Butcher

Phil,
interesting comment you made about the taste with the copper. I have read several very reputable sources say that a bit a copper incorporated is a good thing. Also I am curious of the design if you need a tubing setup like that. PM me if you want some designs that are easy to make and use.

I agree ,your process is more questionable than the materials you use.