bending stainless tube?

skyflyer

skyflyer

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I see that 25mm is a standard sized for steel 1.5mm wall conduit for electrical installations so presumably i could hire the appropriate set of pipe-benders for the day to put a small 20 degree bend in my pedestal angle guard to make it easier to read and use the instruments in their pod mounted on what is currently a vertical face.

Or can I?

I am aware that stainless has very different properties to mild steel. Am i going to split the tube - or some other disaster -by trying to do this?
 
skyflyer said:
I see that 25mm is a standard sized for steel 1.5mm wall conduit for electrical installations so presumably i could hire the appropriate set of pipe-benders for the day to put a small 20 degree bend in my pedestal angle guard to make it easier to read and use the instruments in their pod mounted on what is currently a vertical face.

Or can I?

I am aware that stainless has very different properties to mild steel. Am i going to split the tube - or some other disaster -by trying to do this?
Click to expand...

I am in the process of bending stainless steel tube (22mm O/D 1.5 wall with a hand bender a little more robust the a conduit bender.

Like this

GPIPHB-001.jpg


http://www.adendorff.co.za/ProductD...haping/Thin-Pipe-Benders/HAND-PIPE-BENDER/331

Radius of bend about 110 mm. I need a big pipe as I am a weakling and doing it cold.

A 25mm former is also available and these come from china so should be available from some where like machine mart in the UK.
 
Stainless tube work hardens far more than mild steel equivalent. I have bent some about 10 degrees using a conduit bender but it took a two metre extension to the handle to give enough leverage. It needs to be done in one go to reduce the work hardening effects, stopping and re-starting is not the way to go. If you can hire a hydraulic pipe bender it would be easy but I met up with all sorts of difficulties from the hirers when I did mine.
 
Hydraulic pipe bender pipe bender is only for thick wall tube like schedule tube . A press bender will not give you a fair bend.

Best type is a mandrel bender but not available as a hand machine.

A mandrel bender is what you need if you wish to have a tight bend say less that a rad of 3 X tube diameter

I used to work as a designer for a tube manuliping machine manufacturer when I lived in the UK.
 
well i don't need to bend it much, 20 degrees would be fine. Vyv - is it simply a matter or applying extra leverage or is there a risk with the work hardening that the pipe will split rather than deform maybe?

Basically I am replacing a tin instrument pod with one that is bigger and thicker to accommodate new instrumentation etc and as it stands the faces of the instruments will be a bit close to the forward face of the wheel, particularly tricky if buttons need to be pressed or fails rotated etc.

The new pod alread has a 7 degree inclined face, so an extra 10 degrees would give a total of 17 degrees which is helpful

Alternative is to buy a new angle guard - not cheap!

Rogershaw the conduit bender i was thinking of hiring was this one, which looks pretty robust
8797705732126.jpg
 
I bought one and made the entire frame for my cockpit cover. As vyv suggested it is entirely possible but you need some way of anchoring the feet to the ground and about 2 metres of scaffold pole as an additional lever. I also found it necessary to use a full former. In other words a straight former with a half form of the diameter cut into it to put on top of the bar when bending with a parallel roller on top rather than the formed roller shown in your picture. It's all possible but not easy. I could do it for you but you would need to come to the Solent area which is a bit of a run for you.........
 
The one I used was the twin of the one in your photo but as Mike says it was bolted to the floor. We also put a length of scaffolding pipe over the handle. I was applying an additional bend to each leg of an existing boarding ladder, which was not very easy to fit into the machine. You may need to plan carefully before starting it. I don't think you will split 316 SS tube with a machine like this, 316 is a very ductile material. Once work hardened you may need a 4 metre lever :)
 
boatmike said:
I also found it necessary to use a full former. In other words a straight former with a half form of the diameter cut into it to put on top of the bar when bending with a parallel roller on top rather than the formed roller shown in your picture.
Click to expand...

A friend is currently engaged in DIYing a radar arch and bimini frame and has found the same thing; the roller on the 'bending bar' is denting the SS tube and he's going to have to use a former there too.
 
PCUK said:
If you're ever near Tiverton (Junction 27 M5), I'll do it for you - no charge!
Click to expand...

Driving past on saturday as it happens on way to the boat, but I'm guessing that isn't going to find you at work :-)

I'll give Warren engineering a go at tewkesbury though -

Thanks everyone
 
Well, the problem is solved - or will be by tomorrow morning - as I was down by Stourport marina on totally non-boat related business (there's and industrial estate there) and popped my head in to the office where I was put in touch with "Ron the Rail" who is the local stainless steel craftsman - and by all accounts a real craftsman, and very reasonable charge! What a nice chap too!

So thanks everyone for pointers and help.
 
Interesting thread, although I'm looking for a pre-bent piece of tubing rather than the tools to do it myself.

I s'pose I need to take the pulpit off some forgotten wreck in a scrapyard. Whilst rewarding the proprietor, obviously.

Anybody know of somewhere with such a supply of cheap pre-formed tubing?
 
dancrane said:
Anybody know of somewhere with such a supply of cheap pre-formed tubing?
Click to expand...

Yes.

The Chandlery Barge at Bursledon Bridge. They have lots of 'preloved' boat gear, and although Old John Foulkes has shipped out for 'Fiddlers Green' and the prices have caught up with the Generation Y that run the place now, it's still well worth an occasional visit. Beats the hell out of Force 4 nearby....

Oops! I was keeping that a secret... Now everyone will be heading there!
 
skyflyer said:
well i don't need to bend it much, 20 degrees would be fine. Vyv - is it simply a matter or applying extra leverage or is there a risk with the work hardening that the pipe will split rather than deform maybe?

Basically I am replacing a tin instrument pod with one that is bigger and thicker to accommodate new instrumentation etc and as it stands the faces of the instruments will be a bit close to the forward face of the wheel, particularly tricky if buttons need to be pressed or fails rotated etc.

The new pod alread has a 7 degree inclined face, so an extra 10 degrees would give a total of 17 degrees which is helpful

Alternative is to buy a new angle guard - not cheap!

Rogershaw the conduit bender i was thinking of hiring was this one, which looks pretty robust
8797705732126.jpg
Click to expand...

Sort of thread drift. ----I have one of these . Had it for years. If anyone in the Bradwell marina is stuck they can come round & have a go ---- but it does not leave my sight so you have to bend it at Bradwell marina or my house at St Lawrence Bay
PM me in the winter if needed
 
Slightly different question but is there any way applying very small bend to sections of pulpit while it is in situ? Slight accident last year and the uprights are a bit bent a bit to one side, though you probably wouldn't notice at first glance. I don't want to remove it because I suspect it would be exceptionally difficult to reseat with the accumulated movement of almost 30 years.
 
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