Captain Robert

You most likely don't need to heat the metal at all. The most weight you probably want on a bike trailer is 100# or 45kg so even metal conduit will handle the load. Borrow someone's pipe bender (check your local tool library). There's no need to over think or over engineer the hitch.

Thank you! Three years on, I recall the making of the video with greater fondness than the making of the boat.

Well, I'm the terrible dad who'd be yelling at the kid to get out of the way you're blocking my view.

Thank you for offering your expertise! You've described exactly what I'm doing: pushing on the tube past the point of elasticity and just to the start of plastic deformation. A 20 foot stick of cold-rolled steel up to about .090 wall thickness will deform permanently with just careless handling!So what I'm doing, without using calculations, is feeling for the moment that steel begins to give way. One just has to be sensitive to the "shoulder" of the stress/strain curve.The geometry makes a difference because a piece of 1" x 2" tube is much much harder to bend in the 2" direction. I can barely do it with a stick of .065 wall.