Central Heating Rad Problem

[raybush]

I'm looking to change a small central htg radiator ,but have a problem with a valve spindle ,the problem being that when I close the valve I get a small dribble of water through the spindle which gets worse once it's closed.I'd normally give the small nut on top of the valve a quarter turn ,or remove it and re-pack around the spindle, unfortunately where the spindle has let water escape it has slowly turned to scale and the nut cannot be moved .
I don't want to drain down as it's now the wrong time of year (should have done it in summer) and wondered if anyone has an idea how to remove hard scale that looks like it's in the thread of the nut .........I suppose a freezing kit could be used???? ,if that worked i'd wip the old valves off and change the pair ...anyone used a freezing kit?? and would it work on about 6" copper tails that come out of the floor.
Thanks

[alavahalf]

No ... dont use a freezing kit or it will end in tears. You will still need to drain the rad down if you are changing the valve. What is the issue with draining the whole system, it shouldn't take more than 10 minutes to drain down.
I could tell you a story about me a frezing kit and a 6000 gallon tank of water.... but I wont.

[The Builder]

I think Homer's right. Freezing kits are not for the faint-hearted, especially if you're not used to them.

I've used freezing many times to do something like this. It would be fine on the tails you have, but you do need to have had some experience of them.

It really would be easier for you to just drain down. There's no panic then.

[malagabob]

Try WD 40 or a little heat from a blow lamp and I mean a little. Then repack with a few turns of PTFE tape.

[raybush]

Thanks for the replies .
I'm currently trying the WD around the nut in the hope that it may loosen the scale ,i'll give that a go for a few at and then have another try, failing that i'll wait and drain down in spring .