Checking the bottom

[LakePirate]

I'm pulling the boat out today to check the bottom for redoing. My marina boat yard is doing it. What should I be looking for to compare to what they tell me it may need. I don't think they will try to mislead me but I would like to know ahead of time what they will be or should be looking for.

[MARC2012]

Ck for blisters,cutlass bearing.Ck hose on stuffing box.Make sure all seacocks work.Ck rudder,pintels if applicable.I ck around thruhulls to see if leaking around them.Shaft Zn replace.Status of prop.Good luck.marc

[sailingdog]

In addition to what Marc said, if your through-hulls are bronze, check them for dezincification. This is done by cleaning them thoroughly and inspecting them for "pinkish" spots. If you see this, that means the bronze has been attacked galvanically and is probably due for replacement. Same with any other underwater metal pieces that are bronze, like props, struts, etc.

This photo, by Maine Sail, shows the dezincification* of a prop that was painted with standard bottom paint, and the copper in the paint attacked the metal of the prop.




Also, check to see if there is any "weeping" of water from the hull, especially around the through-hulls. This can often mean that water has gotten into the laminate or core material if the boat has a cored hull, and can be signs of far more serious problems like hull delamination. We had a SeaRay powerboat at my marina that dripped for days--to the point the owner had a surveyor come down to look at it. The surveyor found high moisture readings throughout the hull and drilled two large holes into the hull near the keel, and water poured out for over a week. The boat was declared a total loss by the surveyor as the entire hull was starting to delaminate due to core rot.

*Dezincification refers to the leeching of the zinc from the bronze alloy, which basically leaves a fairly porous and weak copper sponge behind. Some alloys do not contain zinc but suffer from a similar process when the aluminum, another cathodic metal, is attacked and results in much the same end.