I'm the new owner of a '86 C36. I was checking and mopping up the bilge yesterday and I found that the aft keel bolt under the fuel tank is corroded. Unfortunately was not found by my surveyor now I'm stuck with the problem. My question is how concerned should I be? Does it need to be fixed emedietly or can it wait for the next haulout? I can see 8 others that look good. I did not look at the one forward of the mast yet but plan to inspect on my next trip out to the boat. Not sure why the one aft bolt would be so corroded while the others look good. I also think there might be some water coming in from around the aft bolt. Hard to tell without pulling the fuel tank but there is always a bit of water in the bilge. I sponged it all dry yesterday and there was a small puddle starting to form after 3 of 4 hours. Is this normal for an old boat?
Checked the forward keel bolt today. Looks ok and forward bilge was dry. Took a picture of the aft keel bolt. Not much there. Anybody ever dealt with this issue?
The water could easily be coming from your prop shaft packing. These will drip 4 or 5 drops per minute when they are adjusted properly. This water will end up in the area of your keel bolt.
Your keel bolt problem is outside of my experience. A good start would be contacting the surveyor (or another trusted surveyor) and ask him/her for advise. If they are good they can point you in a path to get this fixed (either profeshionally or DIY). It could be as easy as removing the old corroded nut, chasing the threads and torquing on a new nut (work best done on the hard). If keel stud is bad then the repair becomes more complex.
I’d be interested to see a photo of the side of the nut with the water removed.
Good luck,
Ray
Ray & Janice Taylor
"Mizu"
Hood River, Ore.
#2113 2002 TM
It looks like an aerial view of Mars. What are we looking at? Maybe send another shot that shows more of bilge area. Is the nut still attached to the stud? Do you see any sign of a nearby electrical wire that perhaps grounded out on the stud?
I agree that the water is probably from the stuffing box.
Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B
From the photo, it looks like a washer is imbedded in the bilge floor and only remnants of the stud exist with no nut? Out of curiousity, see if a magnet sticks to the stud. If so, it indicates the stud is not made from stainless steel as it should be.
Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B
Wow, tough to understand what we're looking at with water over top. Suck out the water with a drill pump, or small wet/dry vac or other suction device and dry the spot and re-take the photo and post please.
Appears that the boat/nut are totally corroded away. if all the other bolts are OK, then it probably isn't a big deal UNLESS when you haul the boat out you see a crack between the lead keel and the fiberglass skeg at that spot. Given that this is unlikely (the numerous bolts are over-engineered to accommodate one failing), it appears that your vessel unfortunately either had a stainless steel bolt that was bad (it can happen, bad mixing of the zinc in that batch or a regular steel washer or nut or both will et off the rusting), or they mistakenly used a regular steel bolt in that one spot.
It does look like there's a build-up of corrosion around/over it that requires cleaning up and then sealing with sealant or fiberglass resin after applying Rust Converter or similar.
Kevin Lenard
"Firefly"
'91 C-36 Mk. "1.5" Tall Rig, Fin Keel, Hull #1120, Universal M-35 original (not "A" or "B")
CBYC, Scarborough, Lake Ontario, Canada
Tough to reach my hand thru the space under the fuel tank. I was able to clean up most of the water and snap this pic. I can make out a slight hex pattern around the nut now. I can see that the washer is still there. Not sure what else I can do to fix this problem. Not sure if it's even worth fixing if it is still doing it's job. Has anyone seen a keel bolt like this?
Some of the older boats put gel coat over the nut and stud. That might just be a very dirty area and the coloring is from other debris and such from the engine giving the rust color.
That's the good one.
The bad option can be bad. Is the rest of the bilge that unsightly?
Thanks for the response. PO installed a new fuel tank over the top of the keel bolt in the last few years so they must have seen the issue. They had access to the bolt but decided not to replace it for some reason. The keel to hull joint looked good at haul out in Jan. The rest of my bilge is clean and the remaining 9 keel bolts are shiny.