Hi All,
I am re building a very tired wooden 'double ender' fishing boat built 40
years ago in Redcar UK.
Along each side of the keel / stem, is a gap between keel & first plank
which is packed with caulking cotton covered with putty mixed with lead
powder.

Question, In what proportion does the lead powder get mixed with the putty?
( I understand it keeps the putty flexible)

All suggestions appreciated ( well the clean ones anyway)

Best regards,
Stu Knowles.
Doncaster UK