Supporting Hunter 170 for centerboard removal

Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
My '98 Hunter 170 (which I have sailed only in light winds since I bought it about a month ago) is taking on water at about the rate of 1/3 gallon per hour. I have sealed everything I can find close to or below the normal waterline, so I am considering attempting to apply sealant at the seam where the Luran laps over whatever makes up the inside of the centerboard hole. There are also penetrations where the supporting hardware attached to the hull that I cannot get to without removing the centerboard.

I am seeking recommendations as to how to do this while causing the minimum amount of stress on the hull. I have considered beaching it and pulling it over on its side, but that would put all the weight of the hull on one point on the gunwale, and all my water access is public, so I cannot leave it unattended while the sealant dries.

Even if I had the manpower to lift the boat and set it on cradles, that would place the stress in two locations fore and aft of the center. Constructing a cradle with runners similar to those on my trailer would require time and materials that don't make sense for what I hope is a one-time operation. Again, without the manpower (or mobile crane) to lift it, this does not seem like a viable option.

I could rent a lift from a local construction rental concern for $375. I have access to enough open area to do this, but would prefer not to spend the money.

I could set up a few gin poles and cable hoists with properly-rated lifting straps placed fore and aft of the center of the boat (two fore, two aft to spread the load). I would place hefty sawhorses beneath to protect me should they fail.

This all seems like a lot of work to prevent taking on a mere 16 pounds or so of water in the course of a 6-hour excursion, but when I drain the bilge, I am getting little pieces of wood coming out with the bilge water, and wonder if the water getting in is compromising the exposed wood within the hull. I am making a practice of leaving the access hole in the cockpit open during storage to help dry things out.

What say you experienced skippers? Don't sweat it, just drain the bilge and let it air out? Attempt the repair? If so, any advice on how?

Thanks in advance!
 
Feb 21, 2019
42
Catalina 30 TR 3571 Cocoa, FL
As far as CB removal is concerned - for other reasons I've contemplated pulling the CB in my Hunter 18. My current thinking is (3) 2X4X8's joined at the top to form a tripod with 2 legs shortened to sit on each side's cockpit seat with the forward leg pinned to, or sitting over the mast step so the top of tripod is centered over CB pivot bracket. I'd put some plywood scraps or other shim material under the cockpit legs more to protect finish but also spread the load and make sure the forward leg is secured in some manor to the mast step to prevent shifting. Tie the legs together down towards the tripod base with 1X2, old pvc water pipe, etc to keep them from spreading. Fashion a lift point at the top connection point to attach your mainsheet / block assembly and use enough removable fastening hardware to facilitate transport to your launch area. Launch w/o the mast in enough water to lower the CB, attach boom block hanging from tripod to ftg on the board, remove the CB pivot bracket fasteners and lift the assy' out. Not sure about the 170 but the 18 has a flap assy that has to come off the bottom to get access to the trunk /hull joint now working from below with boat back on the trailer.
While cheap, this approach may still be too much effort depending on your frustration level at taking on water.
Let us know if you do pull the board and how you went about it as I still haven't pulled mine. Good luck!
 
Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
OK, that could work. I would have to give everything time to dry out before I seal things up, but this would save me the hassle and hazard of lifting the boat and working under it.

Thanks!
 
Sep 22, 2018
1,869
Hunter 216 Kingston
I’m curious why you have concluded the water is coming in from the centreboard trunk? I know you mentioned you have sealed up some areas but that doesn’t necessarily mean they stay sealed when under load. For example the force of using the rudder could be opening up an area you think is sealed and letting water in that might not happen if the boat was just sitting at the dock.
 
Apr 16, 2017
841
Federation NCC-1701 Riverside
My '98 Hunter 170 (which I have sailed only in light winds since I bought it about a month ago) is taking on water at about the rate of 1/3 gallon per hour. I have sealed everything I can find close to or below the normal waterline, so I am considering attempting to apply sealant at the seam where the Luran laps over whatever makes up the inside of the centerboard hole. There are also penetrations where the supporting hardware attached to the hull that I cannot get to without removing the centerboard.

I am seeking recommendations as to how to do this while causing the minimum amount of stress on the hull. I have considered beaching it and pulling it over on its side, but that would put all the weight of the hull on one point on the gunwale, and all my water access is public, so I cannot leave it unattended while the sealant dries.

Even if I had the manpower to lift the boat and set it on cradles, that would place the stress in two locations fore and aft of the center. Constructing a cradle with runners similar to those on my trailer would require time and materials that don't make sense for what I hope is a one-time operation. Again, without the manpower (or mobile crane) to lift it, this does not seem like a viable option.

I could rent a lift from a local construction rental concern for $375. I have access to enough open area to do this, but would prefer not to spend the money.

I could set up a few gin poles and cable hoists with properly-rated lifting straps placed fore and aft of the center of the boat (two fore, two aft to spread the load). I would place hefty sawhorses beneath to protect me should they fail.

This all seems like a lot of work to prevent taking on a mere 16 pounds or so of water in the course of a 6-hour excursion, but when I drain the bilge, I am getting little pieces of wood coming out with the bilge water, and wonder if the water getting in is compromising the exposed wood within the hull. I am making a practice of leaving the access hole in the cockpit open during storage to help dry things out.

What say you experienced skippers? Don't sweat it, just drain the bilge and let it air out? Attempt the repair? If so, any advice on how?

Thanks in advance!
Just remove the safety lag screw on the centerboard and lift the whole thing up and onto the floor or bench. Place some padding on the trailer. It no more than about 70 lbs. Easy.

The rotten wood is from either a motor mount or rudder mount.

If you think its leaking from centerboard area then check the actual mount that holds the centerboard. There are vertical seams in there that go below the waterline too that might be suspect.
 
Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
I’m curious why you have concluded the water is coming in from the centreboard trunk? I know you mentioned you have sealed up some areas but that doesn’t necessarily mean they stay sealed when under load. For example the force of using the rudder could be opening up an area you think is sealed and letting water in that might not happen if the boat was just sitting at the dock.
The areas I have sealed - top of entire rub rail and bottom at and near transom, motor mount, rudder mount, and bilge plug housing, have all been sealed within the last month. I am fairly confident these are not the source, though I cannot be sure. It's a process of elimination, and I see more potential for leaks in areas that I have not recently addressed than those that I have not addressed at all.

The rudder mount was removed, surface and gasket cleaned, then re-set with sealant between the hull and the gasket, on the shaft of each screw, and around the entire rudder mount. Pretty sure it's sealed, or at least well enough that it's letter more than a quart of water in per hour.
 
Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
Just remove the safety lag screw on the centerboard and lift the whole thing up and onto the floor or bench. Place some padding on the trailer. It no more than about 70 lbs. Easy.

The rotten wood is from either a motor mount or rudder mount.

If you think its leaking from centerboard area then check the actual mount that holds the centerboard. There are vertical seams in there that go below the waterline too that might be suspect.
I was thinking that the centerboard needs to be in the down position to extract it, but looking more closely at the owner's manual, that may not be the case. I will see if it will slide forward enough to allow it to be removed.

I have recently secured a 4x4 timber to the trailer underneath the centerboard to provide relief to the the centerboard uphaul and the tabernacle to which it is attached, so the the centerboard is already well-supported. Hopefully it will not hinder removal. We'll see.

I did try sealing up the centerboard mount, but was not able to access anything more that what is exposed underneath. A crosspiece on the trailer is directly in the way there as well, but I will see if I can find a way to work around that.

Wood could also be coming from tabernacle mount as well, correct?

Thanks!
 
Apr 16, 2017
841
Federation NCC-1701 Riverside
I was thinking that the centerboard needs to be in the down position to extract it, but looking more closely at the owner's manual, that may not be the case. I will see if it will slide forward enough to allow it to be removed.

I have recently secured a 4x4 timber to the trailer underneath the centerboard to provide relief to the the centerboard uphaul and the tabernacle to which it is attached, so the the centerboard is already well-supported. Hopefully it will not hinder removal. We'll see.

I did try sealing up the centerboard mount, but was not able to access anything more that what is exposed underneath. A crosspiece on the trailer is directly in the way there as well, but I will see if I can find a way to work around that.

Wood could also be coming from tabernacle mount as well, correct?

Thanks!
There might also be a plastic or nylon spacer around the lag screw. Remove both. Then lift the centerboard forward and up. the blade will get notched on the trailer if not careful. once off the pin it can also fall through. I have a trailer with a horizontal cross member that has notched my blade and the center beam forces me to pull the blade up onto the boat deck. I did have to muscle back of boat up and sideways on trailer to get access to the lag screw. Tie line to centerboard strap so that if the centerboad falls down its easy to get back out. Having help is nice.

Mast Tabernacle wood is enclosed in foam. The rudder and motor mount too, but they may also have additional wood exposed in the hull. I looked in the hull for the centerboard mount but didnt ever see anything obvious.
 

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Apr 16, 2017
841
Federation NCC-1701 Riverside
Drain the water before you go sailing by lifting the hitch over your head. Drain into bucket.

When done sailing and before cleaning drain the water the same way.

When done cleaning the boat drain it again, hitch up high.
 
Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
Drain the water before you go sailing by lifting the hitch over your head. Drain into bucket.

When done sailing and before cleaning drain the water the same way.

When done cleaning the boat drain it again, hitch up high.
I have a sawhorse I use when draining the boat, so I try to make sure to get all the water out. I have a 5-gallon bucket on hand as well so I can see roughly how much I am taking on.

I see your point with the three-part draining; to help figure out when/where the water might be getting in, right?
 
Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
There might also be a plastic or nylon spacer around the lag screw. Remove both. Then lift the centerboard forward and up. the blade will get notched on the trailer if not careful. once off the pin it can also fall through. I have a trailer with a horizontal cross member that has notched my blade and the center beam forces me to pull the blade up onto the boat deck. I did have to muscle back of boat up and sideways on trailer to get access to the lag screw. Tie line to centerboard strap so that if the centerboad falls down its easy to get back out. Having help is nice.

Mast Tabernacle wood is enclosed in foam. The rudder and motor mount too, but they may also have additional wood exposed in the hull. I looked in the hull for the centerboard mount but didnt ever see anything obvious.
Your photo has me thinking I should try to snake my borescope in and around the trunk in search or evidence (or lack thereof).
 
Sep 24, 2018
2,549
O'Day 25 Chicago
The boroscope is a good idea. You could probably use an automotive jack to lift the boat up off the trailer a tiny bit. I'm guessing you would only need to raise it an inch to slip a piece of wood under your keel to maintain a gap for the scope

I have hoisted a similar sized boat in the air for centerboard repair. There are a lot of things that can go wrong. If I were to do it again I would pay the marina $100-200 to forklift it onto a cradle. It's not worth the risk or the stress
 
Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
I tried getting the centerboard out by lowering it as much as I could on the trailer. Axle is in the way. I was still not able to slide it forward enough to get it free of the pin. Looks like I will have to put it in the water to get the centerboard out.

The boroscope exam was revealing. From the side I could view it does not look like there is any leakage along the trunk, just at the front, fore of the tabernacle mount. I will drop it anyway to remove and re-seal the mount, and insert any needed filler in the screw holes to make sure everything is tight.

Yeah, the hoisting thing is not worth the trouble or risk in this case. I will address what I can with my current resources.
 
Sep 24, 2018
2,549
O'Day 25 Chicago
I'm not familiar with the setup on your boat but I know on both of mine, removing the centerboard while in the water would cause water to leak through the bolt holes
 
Apr 16, 2017
841
Federation NCC-1701 Riverside
I tried getting the centerboard out by lowering it as much as I could on the trailer. Axle is in the way. I was still not able to slide it forward enough to get it free of the pin. Looks like I will have to put it in the water to get the centerboard out.

The boroscope exam was revealing. From the side I could view it does not look like there is any leakage along the trunk, just at the front, fore of the tabernacle mount. I will drop it anyway to remove and re-seal the mount, and insert any needed filler in the screw holes to make sure everything is tight.

Yeah, the hoisting thing is not worth the trouble or risk in this case. I will address what I can with my current resources.
You are really close. Lift the bow up higher and block it. That should give you clearance.
 
Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
I'm not familiar with the setup on your boat but I know on both of mine, removing the centerboard while in the water would cause water to leak through the bolt holes
In the case of the 170, there is one large screw that passes only through the centerboard that keeps it from sliding free of the large pin it pivots around. It's impossible to tell from owner's manual drawings, but it would stand to reason that this pin is part of the mount that screws in to the bottom of the hull at the fore end of the trunk. Removing the large screw in the centerboard allows one to shift the centerboard forward, then up, freeing the centerboard.

Removing the centerboard by removing the centerboard's retaining screw would not entail removing any through-hull bolts or screws, thus would not allow water into the hull. If one were to remove the mount that (maybe?) holds the pin, then yes, it would almost certainly allow water into the hull.

This has me me thinking though. Perhaps freeing the mount would allow me to drop the centerboard and shift the whole mess back and away from its mounting point while still on the trailer, thus allowing me to reinstall the mount with proper sealing.

Hmmm.....
 
Apr 16, 2017
841
Federation NCC-1701 Riverside
Took some pictures today that might be helpful.

The drain and entire rub rail is usually above water.

There is bottom hull luran is cut open for the centerboard. Its just a "lip" glued to the centerboard housing. One picture wirh the front of the centerboard shows this.
 

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Apr 11, 2020
708
MacGregor 26s Scott's Landing, Grapevine TX
Success! Thanks to everyone for helping me think this through!

Turns out the key to removal of the centerboard on the 170 without having to hoist it or put it in the water is removing the four screws holding the mounting plate to the underside of the boat. Once that is done, the large retaining screw can be removed from the centerboard (actually, I removed it before removing the mount screws) and the centerboard can be removed by lifting it up through the trunk.

I started by lowering the centerboard so that it rested on the axle of the trailer (first photo). The second photo shows the fore end of the centerboard being supported by shims placed between it and the trailer crossmember. This allowed me to undo the four screws holding the centerboard mount in place without having it come down on top of me.

The third photo shows the mount and centerboard once freed. From there, the mount can be slid out of the mounting slot on the centerboard (photo four). I tied a rope to the bale at the top fore end of the centerboard and with a good deal of effort managed to lift it free and set it off to the side (photo five).

I sealed everything that looked like it might possibly allow water in with silicon sealant then re-installed the centerboard and mount, being sure to put sealant between the mounting plate and the hull, in the screw holes, and on top of the screw heads.

An important addendum to this is to take note of what BobbyFunn said earlier: "There might also be a plastic or nylon spacer around the lag screw. Remove both." If what he was referring to was the plastic sleeve seen protruding from the retaining screw hole on the centerboard in photo four below, then it's possible I might have been able to lift remove the centerboard without removing the mount. Turns out that sleeve is long enough to block the slot in the centerboard that slides over the pin in the mount, and very well might be what thwarted my earlier efforts to pull up the centerboard through the trunk. It had to be pulled out to the position shown in order to remove the mount.

Now to see if what I did has had any effect. Stay tuned.
 

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Apr 16, 2017
841
Federation NCC-1701 Riverside
Nice!

Gelcoat the nicks and polish it to mirror finish while its out.

When putting it back seal the centerboard up. The lag screw penetrates deep inside the core exposing a path for water to seap between the laminate structure.