In the series: "What the heck is it?"

[Oscar]

The hull to deck joint, as well as the boom pivot attachements on the floats are caulked, glued, with something odd.... It is (now) rock hard and brittle..... Anyone have any idea what it is? (The boat was built in Canada in 1990)

[Quetzalsailor]

Polyester bonding filler. Sometimes rock-hard and heavy. Sometimes darned hard but very light (like in my old 1968 Newport-built Flying Dutchman). Depends upon what the filler is in the resin.

[Oscar]

Thank you!