bending stainless tube?

[Daydream believer]

Piece of timber spanning the bend & a cramp across the timber to the high point & tighten up.
If doing over water tie cords to the wood & cramps so that everytime it slips off you can get them back
Try not to do in presence of partner as she will get blame even of she is nowhere near you & that does no good for harmonic existence

 

[PaulRainbow]

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.

Length of wood and a scissor jack. If, say, the port legs are bent over to Stb a bit, put the length of wood where the Stb stanchions are fixed to the deck (unless you have better place) and the other end to the top of the port stanchion (the bent one of course). Leave the wood just short enough to get a scissor jack in and jack it over. I'd fix the jack to the bit of wood and have another small block of wood fixed to the jack where it meets the stanchion.

You could spend a few quid and hire a porta-power.

 

[eddystone]

Thanks will try that

 

[Tammany]

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.

Stourport on severn? Love that little town, used to holiday their as a kid, 30 odd years ago, every year with my nan visiting relatives who lived at Wilden top not far from their. Went back last year with the missus and it hasn't changed much at all. She loved the railway and safari park and I revisited some old fishing haunts while their too although we stayed on the river at lickhill manor so got plenty of rod time in on the park too lol. Wonderful memories.

 

[Happy Dayz]

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?

I don't know much about stainless properties, but you can hire such bender kit.

I have to install and bend conduit on occasions, si have my own a pipe bender with stocks and guides. It is easy to get it wrong if not a bit exprrienced.

for a 'one off' perhaps its best to take your fender pipes to a machine shop for best results?

Alan

 

[sgr143]

I was going to suggest that you could anneal the steel between various steps of bending, to remove some or all of the work-hardening. (Like you can do for copper gaskets.)

However, the rule of thumb for the temperature needed (about 40% of the melting point) puts that a bit out of range ... as confirmed by the British Stainless Steel Association, who recommend about 1000C for this - a bit beyond the average blowlamp! (Also, this sort of heating would give you some interesting, but probably unwanted, colours from the thicker surface oxide film.)
http://www.bssa.org.uk/topics.php?article=76

On the plus side, austentic stainlesss steels have a very large tensile strain at the limit of uniform elongation , when the plastic deformation starts to go unstable, forming necks, so if you can apply the force needed to overcome the workhardening, which might triple the stength of the steel* - you should be good to go for bending!

[* typical yield stress of 18-8 stainless, about 200MPa. Typical Ultimate tensile stress, 550-750MPa, Typical strain at UTS (=uniform elongation limit), 40%: http://www.bssa.org.uk/topics.php?article=85]