[Rangerkris]

Wast water pipe compression fittings would last outside, i have found that they fit perfick on some steel tube that i can use on a fruit cage 

[Lardman]

I've had some outside for 3 years without problems. Id expect them to be UV stable as they're often used outside.

[Rangerkris]

Good stuff just need to get all the tube's to the plot and do some work roll on Monday its my day off.

[wozza]

Depends how UV stable they are as they do go brittle in Sunlight over time and the weight of steel tubes may cause them to snap, but how long this will take is the peice of string answer!