One of the (many, many, many) problems with moving the kitchen (at the last minute) into the dining area is that the newly fitted radiator ... the 8mm and 5/16" one with the problematic elbow, would have to be removed. In its place would go the plinth heater we bought to go under the unit I was making in the old kitchen before we decided to redesign the entire ruddy house.
Trouble is the plinth heater is no longer going under my unit, its going under one the missus bought ... so it doesn't fit. Useless. We'll have to do without a radiator here.
What to do with the troublesome pipes? I need the shiny new radiator stop valves from the end. No way can I remove the unions I struggled to put on and cap them off. The pipe us too mangled and I'm not convince the union ever sealed properly.
Knowing I only had one shot and that the heating system was live and I didn't want to drain it, I practiced some ideas with a bunch of tools to crimp the pipe. Wire terminal crimp too - not strong enough. Small vice - not strong enough to seal. Hydraulic crimp tool with a specially made flat anvil- not convincing and a bit big to fit in where I needed. Mole grip ... surprisingly effective.
With nobody at home to help if it went wrong , I unlocked the front door and put my phone within reach with my 85 year old neighbour on speed dial. Not enough material left to use a pipe cutter, I positioned my mole grip, whipped the union off using an oscillating multitool and quickly squeezed the moles ince the end was free.... it worked ... save for a needle thin stream of high pressure water that could have gone anywhere but instead chose my eye.
Then I reached for the fall back option .... and hammered blue blazes out of the pipe end til the water stopped, then folded over the end and soldered it shut. Result.