Can I successfully cut down the size of an antique cast-iron radiator?
Maybe. It all depends on how the long-gone manufacturer assembled the radiator. A cast-iron radiator goes together in sections, like a loaf of sliced bread. Each section attaches to the next with round metal fittings called nipples. Nipples looks like very short pieces of pipe, which may or may not have threads on them. Threaded nipples are unusual in that one side has a left-hand thread, while the other side has a right-hand thread. As the manufacturer turned the nipple one way between the two sections, it pulled both sections tightly together. After a few years of normal use and corrosion, the threaded nipples and radiator sections became one, never to separate again. Because of this, threaded nipples aren’t available anymore. If you’re looking to reduce the size of one of these old beauties, you’re out of luck. And then there are push nipples, which are still available. A push nipple is a smooth piece of pipe that’s beveled. The bevel makes the push nipple wider in the middle than i
