ask this old house
56 tips, tricks, and answers to your home-improvement questions
Q I have a magnetic pickup tool that I use to retrieve dropped fasteners and even metal tools. How long have such strong magnets been around?
—DAVE POLLACK, BROOKLYN, NY
A Magnetic pickup tools like yours, and the one at left, typically use neodymium magnets, which were first developed in 1982. Neodymium, a type of rare-earth mineral that’s alloyed with iron and boron, makes the strongest permanent magnets out there—up to 15 times more powerful than other magnets of the same size. It will grab on to most any piece of ferrous metal that it comes near. On the other hand, as you’ve probably discovered, brass keys, copper coins, stainless-steel screws, and gold rings are immune to neodymium’s magnetic attraction.
—THE EDITORS
Q I replaced my kitchen sink drains using the rubber gaskets provided, and had to retighten them three times in two days to stop the leaking. Should I have used plumber’s putty?
—JOSEPH HURD, SHELBY, NC
RICHARD TRETHEWEY REPLIES: In a word, yes. The gasket on a sink’s basket-strainer assembly cushions the top edge of the strainer’s bell—the shiny piece in my right hand, above—or a friction ring under the sink. But the only way to make a waterproof seal between the strainer and the top side of the sink’s hole is by using plumber’s putty.
When properly installed, this concoction of powdered limestone and oils or polymers will
