Considering the age of my Centurion 32, 35 years, it occurred to me that it might be a good idea at some time to change the boat's thru-hulls. But how to do that? It was clear that the old Wauquiez shipyard hadn't followed the mainstream on this issue: Wauquiez thru-hulls are glassed in!
So I consulted Centurion expert David Merlot on this subject. His answer was blunt: "Do NOT change the Wauquiez thru-hulls!". Here's the story.
The original thru-hulls are made of high-quality sintered bronze ("bronze fritté", the material used in transformer bearings) and have a thickness of 5mm! They were put on the boat mold before the gelcoat is applied and the hull is stratified around them. On the old B&W photograph of the mold of the Amphitrite you can see the thru-hulls at the right side (to protect the thread (BSP) it's covered with a plastic cap during the stratification).
David predicted I would find my 35-year old thru-hulls intact and healthy (no pink colouring indicating any electrolytical damage) and so it was. So I didn't change them. Btw, the photograph at the top-left is from another Wauquiez owner on the web, who did take the trouble of taking them out. I hope this blog entry will avoid others making the same mistake.