E38 Keel Bolt Project

Thanks John, I may take you up on that offer!

Here are some more shots of the keel bolts. Should be better quality. Input is appreciated. Thanks, RT

And more...

And more.... If you haven't figured it out I'm signed in under my wifes account. She was online before me, etc. RT

Although the keel bolts look in pretty good shape for an older boat, it seems that the minor corrosion on some of them is about half way up the visible part of the bolt--my guess is maybe at the bottom of the nut once reassembled.

That would suggest that the corrosion was caused by water in the bilge getting at the bolt just below the nut, rather than water coming into the keel/hull joint. If it was the keel/hull joint, I would anticipate the corrosion to be just at/above the keel, not a few inches up, but the first inchabove the keel on all the bolts looks free of any corrosion.

Does my logic make sense, or are there other factors at play.

Thanks,
Frank.

Frank,
You are correct. There is really no way the keel joint was leaking given how aggressive the bond was. I think that water in the bilge did the damage seeping down from the top. This would indicate that simply removing, cleaning, rebedding and retorqueing the nuts every few years is a good idea.

The metal repair compound is called "Belzona" I just remembered the name. Looks like an interesting product.

RT

Update:
Three of the keel bolts have been welded up and the threads then re-cut with a special die. Other than the welded area being slightly shinier you cannot tell where the repair occurred. The keel bolts were passivated with a brush on gel. The results were amazing. Very clean metal when it was all done. The remaining keel bolts with minor pitting are now being coated with Belzona and the keel sump was filled with epoxy, filler, etc. After 72 hours the Belzona will be cut with the die to reform the threads. The keel shoe on the hull has been chiseled clean, ground down and then coated, filled and smoothed with colloidal silica thickened epoxy. If all goes well the keel will be reattached on Thursday 2/28. Initial torque to 50ft/lbs and after a 7 day cure time final torqued to 250-300ft/lbs. Then the nuts will be sealed with a coating of epoxy. Pics of the keel resto shortly.

RT

Here are some pics of the keel ready to be reinstalled. You can see in the first pic the welded and re-threaded keel bolts. Notice the little locating tabs the yard screwed into the keel? Make perfect alignment a no-brainer when it happens. There is some goop on a few of the keel bolts as they were prepping for installation and then decided it was too cold. It will have to wait for warmer weather next week. I am looking forward to having the boat back in one piece. RT

Those keel bolts look good, RT. You might want to build a temporary "fence" around the keel with thin sheet metal or stiff cardboard. That way, when you put your goop on and drop the hull, less goop will escape from the hull-keel joint and more goop will be forced up into the keel bolt holes to better surround and protect the keel bolts, IYSWIM.

John,
Actually that has been considered. The keel will go on and be snugged up with just 50ft/lbs and left for at least 7 days to cure. Then each nut will be removed and the sealant/adhesive will be injected from the top. Finish off with final torque to 250-300ft/lbs. The sealant/adhesive will be injected through a drinking straw attached to the end of the caulk tube. Why? Well the straw can be pressed flat and slide straight down between the keel bolts and the keel shoe. This will deliver the sealant/adhesive to the bottom of each bolt and fill from the bottom up. Seemed like a neat trick to me. RT

Rob, glad to see all is going well with the keel job. If you can, please keep track of how many tubes of beding compound you use, so I'll have a better idea of how many I'll need.

Thanks,
Don

Well, the keel went back on today! There were some issues that I thought were interesting:

When the hull was lowered onto the keel, both the aft and forward ends of the keel shoe met the keel first. There was almost 1/2" gap in the middle! In reality that is not very much over 7+feet of keel length. The hull moves considerably when removed from the keel and the rig is not pulling on it. I am guessing that a fiberglass boat, even with a TAFG grid, is quite flexible. The hull hung in the Travelift the whole time the keel was being repaired so I think the support was quite adequate. The keel and standing rigging when installed, including the water supporting the hull is what holds its shape. Given the issues others have had with furniture moving after adjusting the rig, sailing hard, etc. I am not overly concerned.

The keel fits to the hull with a slight "step". The layer of epoxy was quite thick and the result is the keel is slightly smaller, maybe 3/32", as it is pulled up closer to the hull. The gasket of sealant is 1/8"+ or so max. Some minor fairing work will be required after full cure.

Regarding the keel bolts and the sealant making its way up into the keel bolt holes. I was informed by one of the techs that almost all of them had copious quantities of sealant squishing out on the inside. The aftmost smaller bolt is the only one that will require attention/filling. After full cure each nut/washer will be removed, the area checked for voids and then final torqued.

Currently the boat is still in the Travelift with the keel blocked so some weight is on the keel but most in the slings. The idea is to allow the sealant to cure for 48 hours before dropping her full weight on the keel and poppets.

For those that are wondering what sealant was used I settled on 3M 5200. I know some will not agree with this choice. I understand why. I did more reading than I care to about tensile strengths, elongation, etc. and 5200 beats all others in most categories. I understand that it is a bugger to remove. Given how difficult it was to remove the keel this time I can't see how it could be worse! There was also some concern about 5200 hardening over time. I have had to remove 5200 that was 10+yrs old and it was still quite pliable. That to me is acceptable lifespan. Likely it will double that figure and in 20 yrs there is a good chance the old girl will be put out to pasture anyway. 5200 may not be the perfect solution but the keel will not leak or fall off so mission accomplished.

So its almost over and the hard work is done at this point. This project has been a bear. Probably one of the worst things, as in most difficult, that a boat owner can get himself involved in. I'm I glad I did it? Yes, very much so. I am much more confident in the keelbolts after seeing them up close and knowing the repairs were done well. I also think it will add somewhat to the desirability of the boat should I ever have to sell it. All in all, if you think you should do it, then go for it. Just be prepared for some frustration. You do feel much better at the end though....

I hope everyone enjoyed the "ride"!

RT

Dferr said:

Rob, glad to see all is going well with the keel job. If you can, please keep track of how many tubes of beding compound you use, so I'll have a better idea of how many I'll need.

Thanks,
Don

Click to expand...

Don, I'll have to ask. I didn't actually watch them do it. I think they have the industrial 5 gallon pail of 5200 anyway.... If I had to guess 6-8 tubes should do it. Remember, you can buy more and return what you don't use! RT

I final torqued the keelbolts today to 250ft/lbs. The 5200 was allowed a 9 day cure time. It is supposed to cure in 7 days in optimal conditions. After torquing there were three little "geysers" of 5200 erupting out of the keel seam on one side. Didn't look like much product, maybe a cubic inch at each location.

The reason is clear, the 5200 had not completely cured. Two reasons for this: 1, it has been relatively cold here. 30's at night and 40-50's during the day. 2, the product on the interior is sealed by the product that touches air on the seam. Kinda like when the tip of a tube cures but the rest is still good.

I have asked several people whose opinions I trust and they said not to worry, it will be just fine. I can accept that. I don't want to take it all apart again anyway! A full cure may take many, many weeks.

RT

Hi Rob,
I just did the keel bolts on my 32-200 in May. I have the wing keel with two bolts in bad shape the rest were ok. I took the keel off, it came off no problem and took it to Mars Metals in Burlington Ontario and they replaced all seven bolts by cutting them out from the side. This way they line up when you put the keel back on. The cost was $1600 US. I brought it up from New Jersey myself they quoted me another $1500 if they arranged freight. The people at mars are some of the nicest people I ever delt with it's worth looking into. The keel fit perfectly and was in brand new condition.

Ed, I came very close to sending the keel to Mars when I did it. The yard I was in was confident that they could rework the existing bolts, they did and all worked out okay. Glad to hear your project worked out for you. Keel work does suck. RT