uxb
Well-Known Member
I need to made a couple of 10- 15 degree bends in some 3/4" stainless steel tube- is there any way to do this without a pipe bender? All I have is a bench vice...
Bending stainless steel tube?
- Thread starter uxb
- Start date
prv
Well-Known Member
I had reasonable success with some smaller tube by rasping out a hollow the shape of the desired curve (actually bent a little further as it will spring back) in a block of softwood, and then pulling the pipe round into it with the whole lot clamped in a vise. The hollow needs to fit precisely, especially from each side, as the tube tries to buckle by getting wider and the sides of the slot need to resist that. I was using copper, a bit smaller than your stainless, but I was pulling curves of 90º or more so perhaps your 15º will be feasible? I wouldn't try it if I didn't have more than enough tube for the job though, so I could afford a failed bend or two.
Pete
Pete
Lakesailor
Well-Known Member
It will kink without a pipe-bender with the correct mandrels. Even with, it's tricky.. S/S is way more difficult than copper.
prv
Well-Known Member
I guess my gouged-out wooden block was essentially a home-made mandrel. But yeah, I wouldn't be keen to try with stainless.
Pete
DownWest
Well-Known Member
I used an old cast iron pulley to make curves in 20mm SS tube. It was a sort of V so supported the tube quite well. SS is way more difficult than copper. Pulley was 350mm dia, so nice curves.
macd
Well-Known Member
Filling with sand and plugging the ends helps with bodge-bending, but with stainless I'd still expect it to kink more readily than bend.
Talulah
Well-Known Member
Lakesailor
Well-Known Member
That video proves that it's sensible to take it to a specialist 
Blueboatman
Well-Known Member
Just take it to the local spray dodger maker and ask nicely for a note or two to change hands..?
uxb
Well-Known Member
That sounds like a good plan.
Lakesailor
Well-Known Member
Wish I'd suggested that.
paul-essex
Well-Known Member
some electricians have good benders for metal conjoint / steel round trunking
Graham_Wright
Well-Known Member
Didn't see it in operation though.
Did on this one ;- http://www.youtube.com/watch?v=6ge6oWOzu9s&feature=fvwp
Talulah
Well-Known Member
I see a business opportunity for you selling kits.
chuzzlewit
Well-Known Member
I did a gentle(2' radius?) 90 degree bend in 1" stainless tube by pulling it transversely round my car's front tyre. The rubber spread the load and stopped any kinking.
AntarcticPilot
Well-Known Member
Wouldn't hiring a pipe bender be cheaper?
James_Calvert
Well-Known Member
Would sliding a plumber's spring inside.the tube stop kinks forming, like it does in copper pipe? But it would have to be the right size. 3/4 inch is the equivalent but not exactly the same aa 22mm copper as I recall. You can wind it out anticlockwise if it jammed after bending. Not something I've tried myself though.
Talulah
Well-Known Member
The issue is pipe size. Typical Plumbers pipe benders do 15mm and 22mm. Pushpits, Pulpits, Stanchions are often 25mm so it's difficult to hire one the correct size.
grafozz
Well-Known Member
as long as the pipe wall is not heavy guage you will be able to bend a small radius such as 15 degs by hand in a vice or inside a larger diameter pipe
if you apply heat to both inside and outside the radius it will help and if you use a longer length of pipe it will add to the leverage .
I have bent several ss tubes by hand after seeing how a tube bender kinked a 25mm pipe !
most recent was a new lightweight 22mm tube anti roll bar for my old sportscar .
if you apply heat to both inside and outside the radius it will help and if you use a longer length of pipe it will add to the leverage .
I have bent several ss tubes by hand after seeing how a tube bender kinked a 25mm pipe !
most recent was a new lightweight 22mm tube anti roll bar for my old sportscar .
rustybarge
Well-Known Member
My boaty nextdoor neighbour was a industal plumber, the big stuff like gunbarrel etc. He told me a story about how they used to amaze the new apprentices with majic. They would give a long lenght of pipe to the new guys to fit to a curved wall, and walk away. The apprentice after a few minutes would lay down a straight run of pipe, thinking it was necessary to get a pipe bender. But where do you get a bender for 3" gunbarrel?
Answer: apply heat from a oxyacetylene torch one just one side of the pipe, quite hot over most of the pipe and white hot in several places, and with practice you can get a constant radius curve.
Would it work with small dia. Pipe?
