ground plate problem

[oldshell55]

does anyone know what might cause a calcification build up on dyna-plate between haulouts?, the plate becomes completely encrusted about 1/4 " thick with a hard white bone like substance. it's the only part that is affected

 

[Keelboater]

Is your boat wood by any chance? This could be the formation of sodium hydroxide. When wood becomes saturated with salt water and there is no sea water to constantly flush the area of the grounding plate, it can create that build up you described. But launch the boat and it disolves.

 

[oldshell55]

ground plate

thanks keelboater, no its glass and the deposit on the ground plate needs to be ground off to expose the metal, its been going on since I first put boat in when new, 20yr