Newbie looking for keel bolt advice (E38 1986)

[EricFox]

I bought my E38 last spring and have had a great time sailing her this summer. When I bought it I knew that there were some issues with the keel/hull seam at the back of the keel going back 5+ years. A flexible sealant had been used on the hull to in an attempt to seal that seam at the back (~18" long). The surveyor wasn't concerned - he suggested to sail it over the summer, then to pull out as much of the sealant as I could once back on the hard to let it dry out over the winter, then repair the seam next spring. Below are a few pics of what was under the sealant - a bigger gap than I was anticipating. The rest of the keel/hull joint looks good.

Seeing that, I went to remove the but on the rear keel bolt to see what was there. There was zero torque on the nut. There were 4 washers under it, and then flexible black sealant down into the hole. There was nothing solid for the nut to seat on hence the lack of any torque. When I dug out the sealant, I saw what appear to be missing chunks of fiberglass at the bottom of that bilge compartment that had been filled with sealant. That appears to be where the standing water around the bolt was coming from. I also found significant corrosion on the bolt where the washers were.

I'll head back next week to investigate that sub-bilge area more closely - where are the access points within the boat for water to enter that void, what does it look like in there with a borescope, etc. I will also take off the nut on the keel bolt immediately ahead of the rear bolt to look for any signs of corrosion (didn't have the right socket last weekend).

Re: the bad bolt, my current plan (after having read almost every post on keel bolts) is to do the following in spring: 1) have a local machinest make a sleeve to make up for the corroded section of the bolt, then build up a resin/glass seat around the sleave for a fastener to seat on; or 2) simply fill the rear keel bolt hold with resin. The first option still allows me to drop the keel down the road - the second would make that a bit more difficult.

Re: the outside work, my plan is to fill the gaps with sealant (4200? 5200? other?) as best I can, then fill the seam either with glass + fairing compound, or used G/Flex epoxy.

My only real concern now is the status of the other keel bolts in areas that I won't be able to see. There is externally or internally to suggest a problem. Given that, I'm reluctant to drop the keel right away. But I don't know how easy it is for water to migrate along the keel/hull joint from the rear of the keel where there is an obvious route for water ingress forward to other keel bolts. The sealant in the gap looks to be holding, but that might not be meaningful. Is it likely that water would make its way forward?

For those familiar with the grid for the E38, is that sub-bilge void supposed to be sealed, or there access points within the main bilge that could feed that area with water? Also, from other posts, it looks like I'm not the only one who has discovered that the nut on the real keel bolt has nothing firm to seat on - does that make sense?

One final question, does anyone know the approximate length of the rear keel bolt? I have seen a picture in one post that makes it look like it might be 6 to 8 inches long.

By the way, for context, the boat is only used in the Great Lakes. It saw some ocean use 25 years ago, but none since. And looking at pictures the previous owner took when he bought it in 2018, I'm pretty sure this damage was all there then.

Any advice most appreciated! Thanks.

Eric

 

[Nick J]

There's been a lot of conversation around the integrity of the bolts and the joint as a whole, but I haven't heard much on the integrity of the hull and TAFG where the bolts are secured. It'll be interesting to follow and see what you end up with.

There's some information on this resources page about the keel and location of the bolts:

Ericson Document - E35 TriAx Grid Crack

E35 TriAx Grid Crack

ericsonyachts.org

The top of your bolt looks a lot like a few of mine.

 

[u079721]

We had that same gap aft on our 1989 E38, and quite a bit of leaking at the keel hull joint. From calling around I got the impression that that gap on the aft edge of the keel was not uncommon on the 38s, suggesting that the placement of the bolts wasn't quite up to the challenge. The advice we got was to drop the keel and rebed with epoxy. Which we did. After that the bilge was "bone dry" and the aft edge of the keel was tight up against the hull.

 

[EricFox]

Thanks for the relies, trickdhat and Steve. I haven't been able to get back to the boat since I posted due to a combination of weather and a death in the family. I'm hoping to get out tomorrow to do some more investigation of the grid in particular.

Trickdhat, thanks for that link to the document on cracking in the grid. I wasn't aware of that. I'll have to take a look to see if I can see any evidence of that.

Steve, it indeed sounds like this is a common problem. I had just assumed that a previous owner had hit something going in reverse, but the high incidence rate makes me think that it might simply be a design issue. I'll see what I uncover tomorrow, but if I can't find any clear evidence of damage to any of the other bolts then I'm thinking that I'll use fiberglass to make a platform for the rear bolt, sleeve that bolt, fill the gap from the outside with 4200, then fill in seam with fiberglass/epoxy. If everything stays dry with that next season then I'll leave it as-is. If I still have water ingress then I suppose I'll have to drop the keel the following year. Does that sound like a reasonable plan?

 

[G Kiba]

I don't know if you saw this Blog post by Goldenstate (who will likely chime in soon). It's the most work I have ever seen posted on a boat. And... Its really well documented. Good job Tom! He has several blog posts covering the damage and repairs as well as some great projects he did prepping his boat to sail to Hawaii. Not that you have the same damage or issues. Just thought the Keel bolt repair might interest you.

E32-200 - Keel Bolt Replacement

After removing my keel from my boat as part of my hull fiberglass repair, it was revealed that my fore and aft keel bolts had weathered excessively. For the forward bolt, given the slope of the leading edge of the keel, the yard decided the...

ericsonyachts.org

 

[Christian Williams]

Does that sound like a reasonable plan?

It does to me.

 

[EricFox]

Thanks, all, for the helpful feedback.

I checked things out further yesterday. The holes in the fiberglass just ahead of the rear bolt are in the rear wall of the transverse TAFG cell immediately ahead of the rear keel bolt. What I discovered is that those transvserse cells have a bottom that is effectively flush with the bottom of the bilge pan. I was concerned that rather than a floor, those cells might be open space down to the keel and therefore a path for water to get to the other keel bolts. That isn't the case.

I also removed the nut on the 1" bolt immediately ahead of the rear bolt - no visible issues - the sealant that would have been squeezed up during the original bedding is still in good shape. Of course I have no idea what the bolts look like further down, but at the least the top looks healthy in a way that the rear bolt didn't. I checked the tightness of all of the other accessible buts - everything is solid.

The one disappointing find is that the corrosion of the rear keel bolt extends down further than I initially thought. I'm no longer optimistic that a sleeve can be part of the solution. I may have to be satisfied with making a platform for the nut to seat against and use what threads remain at the top of the bolt (all the while hoping that what is further down doesn't look quite as bad as Golden States - BTW, thanks for that link, Grant - I had indeed seen those pics previously - largely why I dug down further to remove sealant). I could use epoxy rather than sealant to fill in the void between keel and hull from the outside to compensate for the weakened rear bolt, but that would make dropping the keel if needed in the future more difficult - I'm inclined to instead live with the weakened rear bolt knowing that the other dozen bolts can more than do the job of keeping the keel firmly attached. Based on the lack of a seat for the nut, I'm guessing that the rear bolt has played zero role in helping with that task for the past 5 to 10 years.

Thanks again, everyone, for the advice and links.

 

[Christian Williams]

There is hardly a 30+ year old boat with our keel bolts that does not show some depletion of the metal of the keel bolts result of oxygen deprivation, especially in the bilge. The bolts are oversized, so can accept some loss. It is a matter of degree and probability tempered by owner psychology and acceptance of reality. In the dead of night it helps to believe that no keel has ever fallen off an Ericson as result of rotten bolts, and when you see hulks of cruising boats washed up on the beach they still seem to have their keels on.

 

[EricFox]

The level of overengineering that many have pointed to is a source of comfort. As you suggest, Christian, probability is firmly on my side. I'll fix what I can with the keel intact and channel my late night worrying elsewhere!

By the way, I quite enjoyed your latest video. I counted 11 or 12 on board. That's impressive - the most I've managed is 7, and that felt crowded - much different than when I'm out solo. It's also nice to see video of people still out sailing well past the end of summer - everything up this way is unfortunately packed away until next May - time to live vicariously through those in warmer climes.

 

[Christian Williams]

Thanks, it works if they'll get out of the cockpit. And you probably noticed a reef in 10 knots of wind, which I often do in the slip before guests arrive just to take the edge off. It's fascinating to realize how half the people in the world are unfamiliar with vector analysis, which makes them fearful of collision, and anything that "tilts," which I guess otherwise in daily life is nonstandard. Instant exceptions are anybody who played or plays sports, which apparently educates balance and expectations.

 

[u079721]

Thanks for the relies, trickdhat and Steve. I haven't been able to get back to the boat since I posted due to a combination of weather and a death in the family. I'm hoping to get out tomorrow to do some more investigation of the grid in particular.

Trickdhat, thanks for that link to the document on cracking in the grid. I wasn't aware of that. I'll have to take a look to see if I can see any evidence of that.

Steve, it indeed sounds like this is a common problem. I had just assumed that a previous owner had hit something going in reverse, but the high incidence rate makes me think that it might simply be a design issue. I'll see what I uncover tomorrow, but if I can't find any clear evidence of damage to any of the other bolts then I'm thinking that I'll use fiberglass to make a platform for the rear bolt, sleeve that bolt, fill the gap from the outside with 4200, then fill in seam with fiberglass/epoxy. If everything stays dry with that next season then I'll leave it as-is. If I still have water ingress then I suppose I'll have to drop the keel the following year. Does that sound like a reasonable plan?

That does seem like a reasonable start. But here is one suggestion. See if you can find a way to do some of the final work with the boat in the slings and no weight on the keel. With the weight on the keel that aft edge tends to close up - only to open back up after the full weight of the keel pulls down on the hull. With the boat on the slings you'll have full access to any gap that forms, giving you a better chance to fill it with caulk or filled epoxy or whatever.

 

[EricFox]

I never did a follow up at the end of last season, so here it is now. When I hauled out there was still some cracking at the aft end of the keel/hull joint - not as bad as previously, but enough to let water in. So I repeated the process of removing material and re-glassing, but this time I used GFlex with hope that the extra flexibility will keep it from opening up again. If it does open up again I'll look for something that has no rigidity but that does seal - based on a recent article in Practical Sailor it might end up being something like Shoe Goo.

I also noticed that the plate that I made to hold the rear keel bolt was warped - I had used 3/8 aluminum plate and it wasn't stiff enough. So I have now replaced that with 3/4 steel - by my calculations it should have ~10x more stiffness.

I also just realized that I never followed up with more detail about the sleeve. It turned out that the rear keel bolt had two different threads - larger thread lower on the bolt (where the bolt wasn't corroded), and a smaller thread up top for the nut (that is the part that was corroded). I ended up welding a nut with the large thread onto a coupler nut threaded with the smaller thread, then screwed that assembly onto the keel bolt. Unfortunately it took me two tries to get the two nuts lined up properly (rotationally), but it worked in the end.

I'll find out in October if this fix is any better than the first one - in the meantime, I'm looking forward to some good sailing!

 

[Christian Williams]

For keel joints I use seam compound. It has been around for thousand of years, is flexible, and there are scores of brands and compounds. Shoe Goo I like for shoes.

 

[Kenneth K]

Brilliant idea about the welded sleeve and nut.

It might be worth considering one caution about the stainless steel plate, though. The outer edges of the plate (the edges bearing all the force from the bolt) are resting on the curved walls of the TAFG. While we know the TAFG solidly contacts the keel stub in the vicinity of the keel bolts (it has to, to bear all the pressure from the bolts), once it begins curving upward from the bottom of the keel base, it most likely floats above the hull by fractions of an inch to a few inches in some places. This is evidenced by the "tabbing" areas where the TAFG is cut away so the fiberglass tabbing can fasten the "floating" TAFG to the hull, as below.




My point is the TAFG, by itself, was probably not designed to take keel bolt forces. I'd prefer to see a solid filler piece (an appropriately shaped metal block, or a glob of thickened epoxy) between the bottom of the plate and the top of the keel stub, i.e.,

Just my novice $0.02....

 

[Prairie Schooner]

Eric, thanks for the update. We're redoing our bottom this season and I've been wondering what to use for that joint.
Ken makes a good point. At the least, you could grind a bevel on the lower edges of that plate to distribute the weight more.

When the boats were new and to proper spec, I wonder how much the keel would flex when heeling and bouncing.
Jeff

 

[EricFox]

Thanks for the suggestions, Christian (seam compound - I didn't know that such a product existed), Ken, and Jeff.

Re: the plate, I did file off the sharp edge to help distribute the load, but I think I will indeed go at it more aggressively with a grinder before I launch. Jeff, I'm very curious to see if the fix to the rear keel bolt reduces the flex that has been causing this cracking. Fingers crossed, else I'll go the seam compound route.

 

[Pete the Cat]

I have been a victim of obsessing over cracks in the keels to hull joint and think, after 40+ years, I have come to some peace. Here are my beliefs about this based on spending way too much money and time on them:
1. Most keel to hull cracks are not serious--though inexperienced surveyors love to list them to cover their butts, and boatyards will be mixed on their assessments of the same crack--generally depending on their workload at the time.
2. Cracks to watch: Ones that are the result of a known, significant bottom strike that leak as a result. Fractures in the leading edges of keel are actually less dangerous than those that show in fractured glass at the aft part of the hull/keel joint--this means the hull may have been compromised. Having said that, I hit a rock early in the season with my Tartan 37 at 7 knots and we had a small leak and fractured glass in the aft part of the keel; we pulled the boat at my boatyard and my long time boatyard boss said to put it back in and finish the cruising season and we would fix it over the winter. Which we did for $25k. It wasn't that the boat was not damaged, its just that a well built boat is not gonna sink or have the keel fall off like the flimsy racing boats we have likely read too much about. The boatyard caters to classic wooden boats and they always have cracks in their keel joints and need water in the bilge to keep them floating--so their context is different than those of us who value smooth, crackless, fiberglass surfaces.
3. Keels do flex and will likely have a crack if they are at all deep, bolted, not encapsulated, and if the boat is sailed in saucy conditions. Every boat I have had on SF Bay has developed a hull to keel crack of some kind and none has ever threatened to sink the boat.
4. Most efforts to seal the cracks will eventually fail. I do not have proof of this one, but it has been my experience using all manner of sealants, carbon fiber and fiberglass composites. I will admit, I probably sail a bit harder than average and I am also prone to test the limits of the charts, but I sort of expect some sort of crack every time I haul.
These are opinions, not facts.

 

[EricFox]

Ray, Christian and others helped me to understand that the cracking is less about structural integrity and more about aesthetics. I'm not worried that the keel will fall off - but it would be nice to keep the bilge dry (apart from what comes down the mast during rain). At times I feel like Sisyphus, but at least I know that I can choose to quit pushing on that particular boulder if I want to. Or at least until it comes time to sell the boat and aesthetics do matter!