Rebedding a Keel

Hi All. I'm new to the forum and am hoping I'm not out of place in this request for assistance.

I have an Olsen 911SE which has leaked at the keel bolts for the past ten years. (I won't get into story of the rocks that initiated the issue.)

The question is, Is the lowering of the keel to rebed it something that can be done outside of the experience and equipment of a boatyard? The boat is on a trailer with adjustable (screw type) pads which permit me to release the weight from the keel. My intentions would be to loosen the nuts to allow the keel to drop a couple inches, clean out the old bedding, add fresh and tighten it back up.

Problems? Any insights into feasibility or the difficulty of the task would be appreciated. What is the bedding material that should be used?

Thanks in advance.

 

This isn't a task for ill equipped folks to try. Tightening up the bolts, sure, but dropping the keel on the trailer isn't a real good idea. Trailers don't support boats very well, but enough to putter from the driveway to the ramp, with reasonable safety. This is a job best left to a travel lift or fork lift (or two) and a gig to hold your keel upright as you clean off the hull bottom and keel top at the mating point. This is dangerous work. You don't want the keel to fall over on you, nor the boat. Even if you had several people all turning each screw at the same time, I'd be afraid there would be too much local loading stresses on the areas of the hull the screws are pushing against.

Most any boat yard with some sail experience can do the job. This is a common task for them with sailboats. I like travel lifts holding the boat and a fork lift with a gig holding the keel, though some yards don't like to leave their equipment tied up to long. It's a job that shouldn't take but a few hours and I'd use 3M 5200 if your sure about the condition of the bolts and seal, 3M 4000 if your not.

A boat on stands, the keel in a gig, clean up both surfaces very well, apply bedding and marry the two back together. It's easier to lift the keel to the boat then lower the boat to the keel. Tighten, paint and splash . . .

 

I will respectfully disagree with PAR's argument. I have separated keels with Travelifts, and cranes, and the more laborious method suggested by Trevs. I completely agree with PAR in saying that this is dangerous work and due care must be observed

With patience and persistance, the keel of a small sailboat can be separated with less risk of damage than with the utilization of heavy equipment. LIFT THE HULL. The keel must be supported precisely with shoring and wedges, and the (many) screw poppets turned regularly. The hull should be prevented from movement as much as possible with a few lines thrown over the decks and secured to the trailer. Merely loosen the keel bolt nuts at first. When separation begins to occur, the nuts can then be removed and the hull preventer lines loosened incrementally. At this point, nobody should board or otherwise disturb the boat. If the keel really only needs rebedding, I would try VERY hard not to allow the keel bolts to emerge from the hull, rather, I would allow only enough room to clean the mating surfaces. I would use a 2-part polysulfide such as Detco rather than a needlessly high adhesive polyurethane. The keel shouldn't be glued to the hull, just bedded. I hate finding 5200 used as a bedding compound, as the discovery usually leads to otherwise unnecessary localized repairs. My sympathies if you discover that your own keel is stuck with polyurethane.

I have encountered catastrophic hull damage after hard groundings, usually aft of the keel. Are you sure that water is entering around the keelbolt(s)? You may want to have a surveyor give an eyeball. Removal of the antifouling should allow the detection of any damage to the glass.

Should you decide to ask a yard to make the repairs, they will use the most time efficient method available, usually a Travelift or crane. You can do it yourself, if you possess the care and patience necessary.

DC

 

I saw a 5000 pound fin keel hanging off the bottom of a modern, narrow root design held on with only it's 1/4" bead of 5200 around the top of the fin, as the yacht hung in the travel lift. The bolts had all sheared in a grounding with all standing and except for some distortion of the forward end of the glue line, the bead of polyurethane was all that was holding the lead on.

I agree with betelgeuserdude we all hate to see 5200 bonding anything that needs to come apart at some point. Mostly because we've also had to get it off, but it's hard to argue with it's sealing or holding power. 4000 (polyether) has less of a bond, though is near as difficult to remove from a surface. Personally I use Dolfinite with a small amount of 4000 around the bolts on the keel top, but this means the fin I spoke of earlier would have fallen off and the project for it's repair involving divers. Some swear by roofing patch compound and it has some merit on wooden boats, though hard to paint.

I removed hulls from their keels' by lifting, and keels from their hulls' by dropping (under power) the keel, but when tiring to jack the boat off the well bonded keel with maybe a few bent bolts binding up in the holes (likely after a good grounding) you get lots of local delaminating where the pads are bearing against the hull. You hear plenty of ill sounding cracking, popping and delaminating glass directly over those pad contact areas. This can be kept to a minimum if the jacks are directly under a full width bulkhead, or if there are many more jacks but they rarely are.

I'll bet this boat is supported by four jacks and reasonably blocked at the keel bottom with angle iron or similar, right? I'll also bet the jacks don't land on bulkheads and there real propose is to keep the hull from swaying back and forth while the weight is born by the keel as the bow (maybe a roller) and stern hang in mid air with no support at all. How close is this description to the trailer you have? Ever seen a sail boat left on the hard in with this type of support for some years? I have and it's clear what support the hull is really getting.

The easiest way I've found is to lower the keel after the boat is hanging in a sling (I'd use a chain fall for a boat this size) whereas the boat can be supported properly on bulkheads in the sling or a cradle. If I need to "talk to it" I then can use the weight of the boat and pry or lift. This is what I've found to be safest and most reliable. The keel is then dropped into a cradle to hold it while the work is done. I rarely keep them in contact or the bolts in their holes. It's hard enough to get the goo off the bottom of the hull without the damn keel in the way of good power tools, let alone the dancing around the bolts that has to be done on the fin. This is much easier and faster when you have the room to work.

If you lower with a wrench on each bolt you'll be asking a lot more of those threads then they were intended. Ever seize one under an unduly heavy load? Get out the nut splitter and have the weight on the keel at that point (back to where we started)

I'll bet even further, that if you remove the nuts while the boat is resting on her keel in the trailer and try to jack with a person at each jack turning at the same time, you'll just lift the boat and fin (with lots of very uncomforting cracking and popping sounds coming from the glass) You could then start prying and beating with heavier then you should things at the keel and hull, just to have it drop a bit (very dangerous) till it breaks a weakened bolt or binds one or more bent ones real good in their holes (you really don't think it'll drop straight down nice and even do you). You could lift the boat on the jacks and then loosen the bolts a bit at a time, but this isn't good for the threads in the nuts or on the bolts. You will not have much reach with the lowering of the fin on be backing off the nuts method as there will be little thread to work with above the nuts. So you'll be lifting an inch or so and dropping it down that amount until it hits the trailer again. Then there's more jacking. This sounds like a lot more forethought and planning then necessary, also a bunch slower, little control of the appendage in general scary stuff.

He wasn't willing to talk about the embarrassment of the reasons behind this issue, but as betelgeuserdude suggested, it should be checked out before anything gets tried. If it was beat hard enough to move things a bit, making this issue, it was hard enough to bend things as well. The area behind the keel will be the first place I'd look (as has been suggested) The keel rocks back during a grounding and pushes up at the aft end of the appendage into the hull bottom. Stress cracks, surface deformation, broken away tabbing, etc. form and will give you an idea how hard a shot it took. The bolts will stretch, bent and shear off under these loads, making fin removal much more difficult.

Controlled force is what will separate to two. Control is the key word. You can move the appendage around much easier then the boat, this is why I like the drop the keel from the boat method. I can cock, cant, flex, pivot the fin on a fork lift with full control, knowing the weight will be handled if all, suddenly come away (which is usually the case when you get it positioned just right) The Golly Green Giant isn't around when you need him . . .

 

Huh? No, I've nothing to be embarrassed about. Fortunately, with respect to groundings, I've never owned a high aspect fin keel boat. All of the broken laminate that I've encountered was due to the unfortunate errors of others, or there truly is an abundance of "uncharted rocks", or neutrally buoyant flotsam at 4'-6'.

I think that the first order of business after a hard grounding, besides inspecting the bilges, is removal of the antifouling at the keel root. This gives the best indication of damage. It's always a good idea to call the white haired surveyor that you have on retainer.

Bent keel bolts are indeed a *****. More times than not, I've found keel bolts bent from the manufacture of the ballast keel, and/or the initial installation. This is why I find it easier to work on the mating surfaces with the bolts still within their holes. The most difficult aspect of rebedding a keel is the seemingly simple task of lining up all of the bolts in their respective holes.

The original post was an inquiry as to whether simply rebedding a keel could be undertaken without the services of a boatyard. I say emphatically, yes. I've done so on trailers, on elevators, and on a drydock. It can be done. Now if Trevs lacks sufficient mechanical aptitude that he requires his shoes be fastened with velcro..., well then resorting to the yard may be the best bet.

And yes, PAR, you are entirely correct regarding the poppets landing under bulkheads. I would also add that shoring/wedging the forefoot area and aft of the keel root can be beneficial.

I bet that if they took away your forklift and Travelift, you could still accomplish this task.

DC

 

PAR and betelgeuserdude-

Thanks much for the responses and advice. Yes, I was assuming / hoping that the keel would nicely stay in place as we lifted the hull by use of the pads. Judging from your comments, this is too optimistic?

I have not seen there to be any damage to the hull from the grounding. The bottom is covered with VC17 so its thickness (or lack of it) doesn't cover up cracks. The hull - keel joint's bedding compound is dried out. I've been using the bandaid of Boat Caulking the joint before each season. By season's end, this caulk has for the most part separated from the joint.

The boat's support on the trailer is quite like you described - four one foot square pads per side with an adjustable front support. Last season, we did raise the boat by tightening on the pad screws to lift the boat and keel a couple inches to see if this project was a potential. There was no indication of damaging the hull (cracking or popping sounds).

Again, thank you.

Trevs

 

Well hell, Trevs, you should have no problem since you mention that you've raised the boat already with the poppets. If you really have 4 per side, you're doing better than most. This information leads me to believe that you may have an easy time of it. The point of no return is if you can separate the keel from the hull. Up until that point, you could deliver the boat to a yard. After separation, it's all pretty straightforward, provided you are able to work around the keelbolts still in their holes.

PAR's suggestion of localized polyurethane sealant/ADHESIVE (only around the bolts) and liberal Dolfinite everywhere else would work, but I still prefer polysulfide. If you use polysulfide, resist the temptation to torque the keelbolt nuts for a week or so. When you finally do torque them down, the cured polysulfide will be under some degree of compression, offering a better seal. Polysulfide will last and last. Dolfinite craps out in a relatively short amount of time, and fairing compounds will not adhere to it like polysulfide.

DC

 

I do appreciate your confidence in me. A couple final questions:

What should be the material of choice? You mention the Dolfinite which I don't believe is a polysulfide as you earlier suggest, as well as your warning of it drying out is a concern. The other product - Detco gs1 hull Caulk is mentioned earlier doesn't seem to be available here in the midwest, Are you aware of any alternate?

How much is required for this application / how thick do I spread it?

Thanks again.

Trevs

 

Polyslfide is good for deck seams but not the best choice for keels. It's a two part product and there are better things available, some old, some new. Polydlifide is a relativity low viscosity material and I'd want a thick bunch of goo between me and Davie. Your trailer is above average and should be enjoyed for it worth let alone it's engineering. Sailer's should all be so lucky.

If nothing is amiss (bent or broken stuff) re-bed the beast with the goo of choice. I've pulled Dolfinite off boats that still was quite workable and it is the traditional way of bedding. There are a number of newish products available that out perform the stuff, but I'll bet on it more times then not. The trick is to seal the bolt holes and KEEP the appendage tight. If you're lazy use 3M 5200 as it will give you a few years of grace before you need to do this again, be advised it's a ***** to get off. Push in the bedding material with, a putty knife, well into the seam (after it's closed up) for a good fairing job and seam, to be covered with whatever sets your heart on fire.

Betelgeuserdude, you're quite correct, I'd still have the damn thing off and repaired (usually just before a show) in spite of missing fork lifts. I've lots of big oak trees in my yard and I'm not ashamed of using them.

 

Hi Trevs.

I like the 2-part thiokol polysulfides like Detco and Life-calk. Google each brand and you will get good links for purchase over the internet. If on the other hand, you are able to find a local source for either Detco, or Life-calk, you should be able to return any unused kits. I think that I would want at least two kits on hand, but honestly, I've always been in a position where I could walk over and pick up another kit off of the shelf. I hate to tell you that you only need one or two kits and read later on that you ran out, halfway through the job. Once the two parts are mixed up, the product may as well be applied and allowed to squeeze out, rather than going off in the can. Better more, than not enough.

I would dam the edge of the ballast keel with duct tape, so the material stays put until the hull and keel are mated. Depending on how well matched the mating surfaces are, I would apply 1/8" to 1/4" to the top of the keel. I'm being generous here. Like I said, this is a case where more is better than not enough. The waste will squeeze out and give you tremendous peace of mind. Best to simply contain the squeeze out, rather than try to clean it up. Once the rubber cures, it it easy to trim with edge tools and sandpaper.

Be sure to buy a few boxes of latex gloves, and a handful of tyvek suits. This stuff is incredibly pervasive.

DC

 

Life caulk is a deck seam sealant. It's a fast cure polysulifide, paintable, sandable deck seam goo. Is this want you want to use?

 

Here's your Detco literature. I prefer Detco to Life-calk, but Life-calk is still an excellent compound for bedding a ballast keel. How much time do you need to drop a hull onto a ballast keel, when the bolts are still in the holes?
http://www.detcomarine.com/dcaulkappl.htm
DETCO CAULKING PRODUCTS AND APPLICATIONS

PAR, I really don't have a problem with Dolfinite. Or 5200, or Sikaflex, or Lifeseal, or one part polysulfides, or.....whatever. I do rather enjoy using the best material for the job at hand. I have NEVER had a problem with any underwater bedding job when I've used polysulfide. Polysulfide has some adhesive qualities, while Dolfinite does not. Polysulfide is compressible, while Dolfinite is not. Polysulfide is resistant to petroleum, while Dolfinite is not, polysulfide is sandable and allows adhesion of fairing compounds commonly used at the keel root, while Dolfinite will not. I dare say, Trevs will never have to rebed his keel again if he chooses polysulfide, but I would not be quite so willing to offer my reassurances if he chooses Dolfinite and happens to have another hard grounding.

When I work on traditional wooden boats, I use Dolfinite almost exclusively. For bedding a lead ballast keel on a glass hull, I'll stick with polysulfides.

DC

 

I'm really enjoying the bantering back and forth between you two. I take it this isn't the first issue you both have responded to.

By the way, the trailer is a Coose Sailor's Trailer. Well over-engineered for the task. Complete with tongue extension for backing it into the pond to sail off of it. Can't quite imagine the vehicle needed to pull it back out when loaded.

Again, thanks for your help. This project has to wait for the temps to get above the current 17'F, but I'll let you know how it ends up. (Don't let this message stop your further barbs and suggestions.)

Trevs