Even stainless steel fasteners corrode in a wet, oxygen-starved environment such as our Southwest Florida region. It’s called crevice corrosion. If you see streaks of rust emanating from fasteners or fittings, remove, replace and rebed with a sealant such as 3M 4200. This will hopefully cure the cause of the wet core and rust stain problem. If you'd like us to evaluate your vessel's core and rust stain issues, call us today at#MarinerServicesInc. at (239)776-4253 for a no-cost, no-obligation estimate!