[QUOTE=Jim Cate;3073524]That seems an odd statement. What is different about "modern plastic boats" that causes this phenomenon? And how new must a boat be to require some other form of anti foul paint? And how does copper oxide attack my bronze
No argument that copper based paints should not be applied to saildrive housings... that's a no-brainer, but not what the OP is on about.
The vast majority of "modern plastic boats" use copper oxide based anti fouling
. Perhaps you could advise them of a better alternative.
Modern boats are sailing with aluminum
rudder stocks, aluminum
lower rudder bearings and aluminum sail drive legs
All this aluminum is wet ,submerged in an electrolyte
When you use copper oxide antifoul you have essentially built your boat out of copper
This copper overloads the anodes and attacks wet aluminum , galvanic action
This is The reason you void the warranty on a Saildrive leg when you use copper oxide
“ do not use copper oxide antifoul on the BOTTOM OF THE BOAT “