Sealing Seam Below Waterline

[Kiggsia]

I have a 15 foot aluminum boat with leaking keel seams under the bow shelf, below the waterline. What would be the best sealant to use to seal these seams and around the keel mounting nuts, from inside the hull of the boat, per photos? The keel itself makes the seams inaccessible from outside the hull, underneath the boat.

 

[AShipShow]

Not a tinny expert, but 3M 5200 would be my best guess???

 

[jbcurt00]

Never seen a keel held on by nuts and bolts.... gotta a pix of the bottom side?

GluvIt might do it, but w out knowing why nuts and bolts not sure that'd fix it..

 

[Kiggsia]

Here are pix of the starboard side of the forward part of the keel, and the first flat head machine screw you see in that picture under the bow inside the boat. It is bolting the keel together, and taken holding a mirror under the keel. Definitely an "aftermarket" installation. I just wish they were stainless steel. Will probably have to try and replace them someday.

 

[Kiggsia]

A funny thing about this bolted area, i launched boat Tuesday to do a leak check but didn't see any leaks in this area. So i didn't caulk it. And the water was coming from loose rivets elsewhere in the bottom of the hull.

 

[Scott Danforth]

re-buck the rivets

 

[Kiggsia]

I agree, all the rivets shud b re-bucked, thanx 4 reply

 

[Kiggsia]

jbcurt00, here are pics of the keel and the rusty nuts and bolts holding it together showing a cast aluminum spacer in between, I got the rusty bolts out and bought stainless to be put in later today. Earlier in this thread, I had posted pics of the keel with the aftermarket bolts still in it, showing the head of one of the bolts. I'm wondering what kind of fasteners were there originally....

 

[froggy1150]

Put anti sieze on bolts so they don't gall

 

[Kiggsia]

froggy1150, thanks for your reply. I use neverseize regularly on nuts and bolts, yet for these 1/4-20 stainless nuts and bolts, I covered them with marine grade silicone sealant along with sealing the aluminum spacer seen in the picture of the keel with old bolts removed. I was able to do the job without an assistant to back up on the bolt heads under the keel, by pushing up on the bolt heads with a bottle jack, keeping them on a bind so I could tighten the nuts all the way. I plan to re-buck the rivets when I find an assistant to buck up on the rivet upsettings inside the boat.