Keel to keel stub joint renovation

[Suijin]

Hello folks. I'm in the process of redoing my bottom, having taken off 29 years of bottom paint as well some of the barrier coat. Doing so revealed some work that needs to be done to seam where the keel stub meets the lead keel. Some of the barrier (or fairing) coating on the lead keel has chipped away in spots, and particularly at the top of the keel where it adjoins the stub.

I have received one recommendation to not simply epoxy over the joint to form one contiguous surface, but to instead repair each surface independently and then simply calk the seam in between. The logic given was that a crack will invariably develop in the epoxy if I fair the seam.

Pictures below. Any recommendation on how to proceed based on prior experience would be most appreciated.

[barnakiel]

What condition are the bolts when you look from the top?

Is the bilge dry?

b.

[Suijin]

The bolts look good (no rust) and the bilge, where there are bolts, is dry (there is a "sump" in the aft-most section of the bilge, there the stub is deepest.

The issue I'm contemplating is not leakage, it's just the cracking of the epoxy which may lead to the same deterioration and separation of the epoxy from the keel. It may be ultimately cosmetic, I just want to take the approach that leads to the greatest longevity of the repair.

[barnakiel]

OK. So dry bilge and sound bolts = no leaks.

At this stage I would dig out, at one place only, as much of the old stuff as you reasonably can and inspect how wide and deep the gap between the stub and the ballast is.

Why?

Because I have just finished repairing a keel where the ballast and the stub were not matched flat all the way to the edge but rather there was a groove - half of it on the stub the other on the ballast. The caulking was nearly all on the outer edge only. Now you can imagine this keel had next to nil 'free play' with bolts tight. No movement = can be laminated over ... no cracks. But with the groove so deep, we simply cleaned just the groove, tightened the bolts and applied new caulking into the groove. Job done. No leaks nor anything to pop off.

If your ballast is sitting with more than only filler amount of caulking then there may be some movement as the boat sails. This would render any epoxy/glass fillet last only till your first blustery day on the water.

With good new sealant, laminating over should not be necessary. But from my experience about the only way to apply new sealant well is to lift the boat, clean the ballast and the stub, apply new sealant ... - not worth the effort if there is no leak and the bolts look clean.

PS My boatyard staff used some magic goo for the new seal - not what we typically get off the shelf in our corner chandlery.

b.

[George DuBose]

I used GFlex by West Systems to patch my keel joint. It sticks to metal and to plastics and is quite flexible.

I will have to wait until the next haulout to see how it held up.

The boatyard workers here in Holland recommended Rotobond.

[rognvald]

Suijin,
I had a similar issue on a previous boat. I removed the old fairing compound the full length of the keel, created a shallow "v" with a grinder exposing the keel/hull joint, sealed it with several coats of epoxy barrier coat and then filled the "v" with bedding compound. It was perfect when I sold the boat ten years later with only an occasional touch up of the compound needed. Good luck and safe sailing.

[Scaramanga F25]

What was successful for me was that I put a string around the joint and then I faired the joint with an epoxy filler. As it was almost cured I removed the string
leaving a fine line that I later filled with 5200.

There may very well be some flex at this junction.

[reed1v]

Unless you have water coming into the boat, might just leave it alone. Most likely the flange is well sealed to the hull and what you see is where the excess caulking has been squeezed out over time. Just do a flexible caulk over it and be done with it. Epoxy most likely will crack over time, gaining nothing.

Otherwise drop the keel, get rid of all the old compounds, reseal with new caulking(the keel does flex so rigid stuff will not work), raise the keel and spend a week tightening the bolts, caulk outside, and paint.

We did both methods on a Ranger 26 and a cal 20. Either way works. One is cheap, the other laborious and potentially expensive. Raising a keel back up and keeping all bolts aligned is not a cake walk.

[Suijin]

Originally Posted by Scaramanga F25

What was successful for me was that I put a string around the joint and then I faired the joint with an epoxy filler. As it was almost cured I removed the string
leaving a fine line that I later filled with 5200.

There may very well be some flex at this junction.

This is exactly the procedure suggested by the contractor. You make it sound easier than I had expected, lol. I think I'll give it a shot.