I have been watching a series on UTube by a guy who is rebuilding a wooden boat, the Tally Ho. One thing they do is bed the wooden pieces in what they call “red lead putty” as a rot deterrence. The use of red lead putty in wooden boat construction is apparently routine. One problem with wood-canvas canoes is rot setting in under the outwale affecting both the underside of the outwale and the covered canvas edge. I was wondering if red lead putty might not be adapted to this use. Or is use of lead in any form totally forbidden in the U.S.?