I have just purchased a number of second hand cast iron radiators that were removed from a house and kept in a shed for around six months - I think they were being used for around six years prior to this. I ran a hosepipe through the radiators and one has a couple of leaks which I would like to tackle. The first leak is within one of the section joints and as the radiator is used/rusty internally, I think it will be difficult to unscrew (I plan to purchase a radiator "joining tool" so any ideas on the best place to purchase one of those would be appreciated) so any tips on how I might go about loosening the rusty joint would be appreciated (heat it with a standard plumbing gas torch perhaps). The second leak appears to be within the seam of one of the sections. I have seen on-line examples of people using epoxy to effect a repair but am not sure if this is a good idea. As it is a large radiator I may just take this section out - any ideas/opinions as to whether it is worth trying an epoxy repair?