Tube bending

[Anthonyexmouth]

What's the best diy technique for putting a large/slow bend in a 4m tube to follow the line of the gunwale?

 

[Davy_S]

You don't say what diameter, it could be worth a try if you get two tight fitting wooden bungs for each end, then hammer/ram it full of wet builders sand, then gently try to bend it.

 

[Anthonyexmouth]

Thinking something like 25mm.

 

[PCUK]

Fix a railway sleeper , drill a 25mm hole in it and gently make the curve (it's not a bend) an inch at a time. Worked for us before we got a tube former.

 

[Seastoke]

Thinking something like 25mm.

Depending on what gauge you could use a conduit bender , or a piece of 4x3 wood drill a 25 mm hole on the 3 inch end then taper the hole both sides one one way and one the other , then you can bend the tube

 

[BruceK]

I believe it's an artform getting the railings to match either side. I'd be more concerned about getting a jig perfect than the actual bending.

 

[plumbob]

What's the best diy technique for putting a large/slow bend in a 4m tube to follow the line of the gunwale?

You say "something like" 25mm..............copper?? So much will depend on the material used. Sand loading a length of copper is a good way but I would use dry sand and wooden bungs. Heat to a dull red and use a former made for the job. Done it several times on steam traction engine jobs but only very "slow" bends. Used wet casting sand once .3 weeks in a horse trough to shift it. Good luck.

 

[Anthonyexmouth]

Gonna be stainless or galvanised. I've got to make a handrail to make the gunwale height up to 1m for commercial coding. It's only a work boat so doesn't have to be perfect but good would be nice.

 

[Bandit]

A ring rolling machine.