Bending steel tube

[Idrisdraig]

I'm planning to make a frame out of steel tube.
The lightest steel I can find is 12mm OD, 18swg / 1.2mm wall thickness.

For corners I am hoping to bend the pipe into right angles, without collapsing the tube.
Is this likely to be possible with a spring type pipe bender with this sort of pipe (with or without heat)?

Also what is the smallest radius I could hope for on the bends?

 

[Diyisfun]

I think you will struggle with a spring.
Do a search on pipe benders.
You could always go to a hire shop & try one, then hire not buy.

 

[Newboy]

I suspect that you may have difficulty with the tube diameter that you've chosen.

Bending tools are available but only for industry standard tube diameters

http://www.hss.com/g/68350/Conduit-Bender.html

Your bend radius will be governed by the formers on the bending tool

 

[pinenot]

The old way, prior to bending springs, for a plumber (non Ferris metals admittedly) was to fill the pipe with sand, leaving a 1/4" or so gap at the top, seal the open end. The pipe could then be bent via bender (a yard of 4"x4" placed at an angle on the ground) with the pipe sticking out allowing the bending to commence. Obviously this is a skill, but not to difficult, the sand acting like the modern spring prevented collapse of the pipe walls and the sand could be knocked out afterwards...pinenot

 

[Idrisdraig]

Having looked around I'm considering scaling down the tubes that need to be bent to 3/8" 18sg, or possibly 20swg.
(That said I have no idea of their respective strengths. Could you distort / damage a 12" length of 3/8" 20swg mild steel round tube without tools?)

I did find this brake pipe bender, which I realise is both cheap and cheerful, and intended for copper not steel ...
http://www.ebay.co.uk/itm/121255611459?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649
... but I wonder if I opt for 20swg, and sand, and get it as hot as pos (with a blow torch) whether I might just get a way with it all.

(Hiring a floor standing pipe bender is not something I'd thought of but it might be pushing the cost / effort ratio in the wrong direction. Zero budget!)

 

[Trazor]

http://www.bendalloy.co.uk/polybend.html

 

[Burnerman]

If you are going to bend steel tube without professional gear, you'll need to get the material red hot and keep it there......this would prove to be very difficult indeed - if not impossible - with hand held tools. The brake bending tool is for strictly non ferrous stuff.
Why not hire what you need for a day? You can typically bend from 3/8" right up to 2" diameter cold, and the radius of the bend depends on the diameter of the material. Expect the hire to be around £50 to £60 per day.
John

 

[Idrisdraig]

Thanks for the input.
£50-£60 to hire a pipe bender means the project isn't financially viable.

 

[Burnerman]

OK then - how about buying an existing suitable frame and modifying it to suit your needs.......or constructing one out of copper tube? Daft idea?
John

 

[Idrisdraig]

A frame exists to do exactly what I want.

I can source (or already have) all the materials for £35, or buy a frame for £90. The one hurdle is bending the tubes.

There may be other options, but I'm just trying to find them.

 

[jj4091]

Can you use preformed bends or elbows?

 

[Idrisdraig]

I wondered about that, but the only ones I could find that were a useable diameter were bulky cast items, or expensive polished/chromed ones.
Any ideas where I could find pre formed elbows made from roughly the same tube?

 

[foxhole]

What are you making? or is it a secret.

 

[Idrisdraig]

It's a secret. But a fairly useful one.

 

[foxhole]

I doubt it.