Pop-pop boats are a neat little science teaching tool that many children end up playing with at some point or other. They’re normally sized to float around a sink or bathtub. [Steve Mould ...

You didn’t say, but David Brunatti of Brunatti & Sons, a boat fabric maker in Parry Sound, Ont., suspects that they’re from mould or mildew. The harsher the cleaner, the better it will get rid ...