I briefly mentioned polysulfide last month (see “A Refreshing Caulk Tale,” September 2016), noting some of its attributes, including resistance to UV light, fuel and many cleansers, and its facility to be sanded and painted. Above all these, however, is its ability to remain flexible for years. Unlike polyurethane, polysulfide doesn’t dry to a hard, eraser-like consistency. It’s therefore ideally suited to applications where it’s exposed to flexing or movement, UV light, deck or teak cleaners, or petroleum products. It’s also ideal for bedding antenna bases, searchlights and fuel-fill fittings that might at some point require disassembly or be exposed to certain chemicals, including fuel.