Having seen our alternate toilet wax ring use tip below, Bill writes: “Here’s a rubber cap to seal an open tube of caulk or pretty much anything you lose the cap to.”
He’s referring to the Little Red Cap, pictured above. Its manufacturer, CAP Products, says it “simply rolls on then off to provide a clean, easy solution to capping containers of caulk, paint, sealer, glue, chalk, or anything on your shelf that you wish to reseal and reuse.” They also list a number of more “creative” uses including terminating wire, capping a felt marker, covering the jaws of pliers to prevent marring, waterproofing switches, and so on.
We found an 80-pack of ’em on Froogle for $20, but if you want to give ’em a try we found a 35-pack via Amazon for under $5. CAP says they’re on shelves at ACE, Rockler, Do It Best, and other hardware/tool shops, too.