We read online about replacing keel bolts. I wonder how many sailors or actually doing this? And why? Is it a sort of routine thing... bolts need to be replaced after X years?
Are there signs that bolt(s) need to be replaced?
Are there catastrophic failures from bolt failures? How many?
Who has changed their keel bolts and what were the circumstances?
Is the keel bolt replacement thing more common for some manufacturers?
Iíve been away from internet for a bit and just catching up. If you started a new thread, let me know and Iíll move this post over.
As in all sailing related matters, this really depends. If you have stainless steel bolts and a lead keel, in theory, your bolts could outlast you. The risk is crevice corrosion, if they ever get wet in or below the bilge. We all know that stainless steel must be exposed to air to prevent rust. Submerged it corrodes quickly. They can get wet from a leaky bilge or through the keel joint, from below the waterline. Inspection makes sense. You canít tell from above the nuts.
Galvanized bolts into an iron keel are a different kettle of fish. More likely to corrode, even inside the bilge, which can be seen. However, whether they are corroded below the bilge is still hard to tell. I just replaced mine, which looked very badly rusted in the bilge, but were perfectly good below the nuts and in the keel. Itís great peace of mind to know they are new now and Iíll do a better job keeping the bits in the bilge corrosion free. Iím probably going to paint them with cold galvanizing.
While inspection is called for, itís actually tough to do. In our case, the keel adhesive sealant was pressed up the stud to the back of the nut, making it impossible to see below. I probably could have noted water seepage, or severely corroded studs, but would have no idea what was going in the portion mated to the keel itself.
Keeping oneís keel joint water tight is critical to the longevity of any form of bolt and hard to know if itís the case.