# Chainplate rebedding with mast up



## josrulz (Oct 15, 2006)

Hi all,
I need to rebed some chainplates on our "new" boat. I've done the procedure before on this boat, but the mast was out. 

The part I need help with is the "mast up" thing. My shroud configuration is the standard single spread rig, with fore and aft lowers (3 chainplates each side). I've been told I can run the main halyard to the rail, then mark the turnbuckle position with tape, and remove the shroud to do the chainplate. This makes sense on the upper, but what about the lowers? Can I remove those (one at a time of course) without slacking the lowers on the opposite side? The main halyard will support the top of the mast, but not the middle where the lowers attach.

I just want to make sure that I can safely remove one shroud at a time, replacing before moving on. Or do I need to take some other precautions?

For what it's worth I'll be doing this at the slip on a calm day (it's well-protected where the boat is). 

Thanks for any advice you may have on this.
-J


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## US27inKS (Feb 6, 2005)

Sounds like you're on the right track. This is exactly what I did 3 times before I discovered the wonders of butyl tape. Now go get busy.


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## RainDog (Jun 9, 2009)

I would skip the halyard. I do it this way:

1) Loosen and then disconnect the uppers. 
2) Rebed their chainplates. 
3) Wait until the bedding cures (if you are using bedding that cures). 
4) Reattach and tighten the uppers5) Loosen the lowers
6) Rebed their chainplates
7) Wait until the bedding cures (if you are using bedding that cures). 
8) Reattach and tighten the lowers

You can do them all in 3 days (assuming a 24 hour cures). The stays + uppers is far more than what you need to support the mast at your slip. The same is true for stays + lowers.


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## jackytdunaway (Sep 11, 2006)

What if the upper and lower tie into the same chain plate? You have to do the halyard thing then.


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## josrulz (Oct 15, 2006)

RainDog said:


> I would skip the halyard. I do it this way:
> 
> 1) Loosen and then disconnect the uppers.
> 2) Rebed their chainplates.
> ...


Well, I am planning to use 3M101, which is what I've used before. Can't use butyl tape here because my chainplate covers are not through-bolted, so polysulfide is my preference. It cures over several weeks.

So my assumption was that I could just rebed one at a time, and put everything back together without waiting, since there's really no way to take the boat out of commission for weeks anyway.

Not sure I like the idea of loosening both sides without halyard reinforcement...makes me nervous, even if it does make sense.
-J


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## gtod25 (Aug 5, 2000)

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## RainDog (Jun 9, 2009)

I did mine with 3M 4000 UV. I did the first chainplates and all the stancions on Saturday. On Sunday I reattached the lifelines and the upper shrouds and rebedded the lower shroud chainplates. Monday I just had to reattach the lower shrouds and tune the rig. 101 has a longer cure time than 5200. I would not want to load the rig until the sealant cures, but maybe I am just being superstitious.


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## donradclife (May 19, 2007)

a typical mast will be fine supported only by the lowers or uppers, as long as the wind is less than hurricane strength.

My boat got a new (keel-stepped) mast because the yard disconnected ALL the shrouds and went home for the night. It then blew over 40 knots and folded the mast over onto the neighboring boats.


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## josrulz (Oct 15, 2006)

donradclife said:


> a typical mast will be fine supported only by the lowers or uppers, as long as the wind is less than hurricane strength.
> 
> My boat got a new (keel-stepped) mast because the yard disconnected ALL the shrouds and went home for the night. It then blew over 40 knots and folded the mast over onto the neighboring boats.


I see your point that only the lowers or only the uppers would be OK.

My main question is, do I need to disconnect lowers on both sides evenly, or is it OK to leave them on one side, but disconnect the other to work on them? I wasn't sure if the lop-sided pull would be problematic, or OK for a few hours of work.

By the way, the stinks regarding your mast, but I'm glad to hear you got a new one out of it!


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## sailingdog (Mar 19, 2006)

Not a good choice. First, 5200 isn't elastic enough for the purpose, since the chainplates will move a bit. Second, removing the stuff in the event that they start leaking is going to be a royal nightmare. 5200 and silicone have very, very, few legitimate uses on a boat IMHO.


RainDog said:


> I did mine with 3M 5200 UV. I did the first chainplates and all the stancions on Saturday. On Sunday I reattached the lifelines and the upper shrouds and rebedded the lower shroud chainplates. Monday I just had to reattach the lower shrouds and tune the rig. 101 has a longer cure time than 5200. I would not want to load the rig until the sealant cures, but maybe I am just being superstitious.


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## RainDog (Jun 9, 2009)

Sorry, I meant 3M 4000, not 3M 5200. I agree 5200 would be a very bad idea.


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## sailingdog (Mar 19, 2006)

That's a different story.  much better choice... 


RainDog said:


> Sorry, I meant 3M 4000, not 3M 5200. I agree 5200 would be a very bad idea.


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## knothead (Apr 9, 2003)

josrulz said:


> My main question is, do I need to disconnect lowers on both sides evenly, or is it OK to leave them on one side, but disconnect the other to work on them? I wasn't sure if the lop-sided pull would be problematic, or OK for a few hours of work.


I would recommend first easing all the turnbuckles a few turns just to take the strain off. Then you will have no problem removing shrouds either in pairs or singly. Halyards aren't really necessary, but they sure can't hurt. Sometimes, you can hook the shrouds back up temporarily to the rail too. Just don't load em up.


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## josrulz (Oct 15, 2006)

RainDog said:


> I did mine with 3M 4000 UV. I did the first chainplates and all the stancions on Saturday. On Sunday I reattached the lifelines and the upper shrouds and rebedded the lower shroud chainplates. Monday I just had to reattach the lower shrouds and tune the rig. 101 has a longer cure time than 5200. I would not want to load the rig until the sealant cures, but maybe I am just being superstitious.


I've been told before that with 3M 101, you want to load everything up before it cures anyway (just relaying info here). As one Sailnet member stated at the time, _if you're chainplates are moving enough to break the seal, then you have bigger problems than choice of sealant_.

I rebedded a very leaky chainplate with 3M 101 this spring, a few days before the mast was stepped. We sailed the boat offshore to get her home in pouring rain and waves, and have since had days on the Chesapeake, pounding to weather with green water over the decks. That chainplate still isn't leaking.

Of course, that's no scientific test--it was only been a few months, and I'm no expert here. But I'll try this again, and see how it goes. I'll report back if I run into problems down the line.

Sooo, any votes on whether I should remove the lowers on BOTH sides at the same time, or can I do one side at a time and leave the other side connected? Or does it matter?


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## knothead (Apr 9, 2003)

SD, How do you figure that 5200 isn't flexible enough to bed chainplates? How big a gap do you leave around them anyway? I'm holding a cured chunk in my hands right now. Squeezing it between the jaws of my Leatherman. The stuff feels like a piece of rubber. 
If you have a gap of about a 32nd to an 1/8 of an inch around the plate, how could it not work?


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## scottyt (Jul 19, 2008)

hell i sailed my boat home with out an upper shroud, granted i did it under a reef and no head sail and 5 knot winds


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## sailingdog (Mar 19, 2006)

How old is that chunk, the stuff loses flexibility and elasticity as it cures and ages...


knothead said:


> SD, How do you figure that 5200 isn't flexible enough to bed chainplates? How big a gap do you leave around them anyway? I'm holding a cured chunk in my hands right now. Squeezing it between the jaws of my Leatherman. The stuff feels like a piece of rubber.
> If you have a gap of about a 32nd to an 1/8 of an inch around the plate, how could it not work?


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## mitiempo (Sep 19, 2008)

I think the best reason not to use 5200 is that it's so adhesive, if you ever have to remove it (and you will eventually) that it will pull gelcoat off underlying glass structure. Sure you want the sealant to stick to what you're bedding, but not to that extent. 5200's 700 psi is not needed, 4000/4200's 
300 psi is plenty.
Brian


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## sailingdog (Mar 19, 2006)

Exactly... and for something like chainplates, where the fit depends on the strength of the pieces, and does not rely on sealant for strength... butyl tape is an excellent choice, since it is very elastic and sticky, but not very strong.


mitiempo said:


> I think the best reason not to use 5200 is that it's so adhesive, if you ever have to remove it (and you will eventually) that it will pull gelcoat off underlying glass structure. Sure you want the sealant to stick to what you're bedding, but not to that extent. 5200's 700 psi is not needed, 4000/4200's
> 300 psi is plenty.
> Brian


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## US27inKS (Feb 6, 2005)

I tried several of the sealants mentioned in this thread. Butyl tape finally sealed it for good.


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## mitiempo (Sep 19, 2008)

Butyl tape is also my first choice as my boat (CS27) had most deck hardware and hull/deck joint sealed with butyl 32 years ago. The hull/deck joint butyl bedding is still flexible after this time and there are not too many other issues except those that are due to poor maintenance by previous owners. My second choice is Sikaflex 291 as I find that some items are not able to be tightened enough to fully squeeze out the butyl when installing such as access ports made of plastic.
Brian


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## knothead (Apr 9, 2003)

josrulz said:


> Sooo, any votes on whether I should remove the lowers on BOTH sides at the same time, or can I do one side at a time and leave the other side connected? Or does it matter?


You might have missed my post.



knothead said:


> I would recommend first easing all the turnbuckles a few turns just to take the strain off. Then you will have no problem removing shrouds either in pairs or singly. Halyards aren't really necessary, but they sure can't hurt. Sometimes, you can hook the shrouds back up temporarily to the rail too. Just don't load em up.





mitiempo said:


> I think the best reason not to use 5200 is that it's so adhesive, if you ever have to remove it (and you will eventually) that it will pull gelcoat off underlying glass structure. Sure you want the sealant to stick to what you're bedding, but not to that extent. 5200's 700 psi is not needed, 4000/4200's
> 300 psi is plenty.
> Brian


It's adhesive quality is the thing I like best about it. 

I've used it, removed it and wore it for years, along with just about every other goop out there. It's certainly more resilient and stubborn, but it comes off. And if you tear up the boat in the process, it's not the goop's fault, it's because you didn't take your time and do it right. 
5200 is not invincible. 

There are applications where it is more critical to use a specific substance or material. But for the most part, it's not the goop you choose it's how much you choose to ooze. HA. 

Seriously, it's usually not the fact that the wrong product was used that is causing the leak, the problem lies in the fact that the thing is really overdue for maintenance.

But everyone has their opinion.


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## lancelot9898 (Dec 30, 2008)

knothead said:


> It's adhesive quality is the thing I like best about it.
> 
> I've used it, removed it and wore it for years, along with just about every other goop out there. It's certainly more resilient and stubborn, but it comes off. And if you tear up the boat in the process, it's not the goop's fault, it's because you didn't take your time and do it right.
> 5200 is not invincible.


I agree and have used 5200 and it has held up well on the chainplates and also the stantions. When I had to remove the radar pole which was also beded with 5200, the attachment point came apart without use of heat or chemicals. When I use the stuff I don't expect to take it apart again, but it is doable with some effort and care.


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## josrulz (Oct 15, 2006)

Thanks everyone. I didn't reply sooner since I was out on the boat this weekend.  I appreciate all the responses and help.
Best,
J


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## jackytdunaway (Sep 11, 2006)

Originally Posted by *knothead* 
_I would recommend first easing all the turnbuckles a few turns just to take the strain off. Then you will have no problem removing shrouds either in pairs or singly. Halyards aren't really necessary, but they sure can't hurt. Sometimes, you can hook the shrouds back up temporarily to the rail too. Just don't load em up._

_Knothead,_
_You must be speaking of a keel stepped mast. Certainly a deck stepped mast will have to have something holding it up. On a deck stepped mast are halyards OK while the chainplates are rebed. My upper and lower both go to the same place and i need to rebed but am nervous about taking the shrouds loose_


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## josrulz (Oct 15, 2006)

jackytdunaway said:


> _Knothead,_
> _You must be speaking of a keel stepped mast. Certainly a deck stepped mast will have to have something holding it up. On a deck stepped mast are halyards OK while the chainplates are rebed. My upper and lower both go to the same place and i need to rebed but am nervous about taking the shrouds loose_


Hi jackytdunaway, I certainly can't speak for knothead, but your question made me realize I should have specified that I have a keel-stepped mast. You're absolutely right that would make a huge difference.


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## knothead (Apr 9, 2003)

jackytdunaway said:


> Originally Posted by *knothead*
> _I would recommend first easing all the turnbuckles a few turns just to take the strain off. Then you will have no problem removing shrouds either in pairs or singly. Halyards aren't really necessary, but they sure can't hurt. Sometimes, you can hook the shrouds back up temporarily to the rail too. Just don't load em up._
> 
> _Knothead,_
> _You must be speaking of a keel stepped mast. Certainly a deck stepped mast will have to have something holding it up. On a deck stepped mast are halyards OK while the chainplates are rebed. My upper and lower both go to the same place and i need to rebed but am nervous about taking the shrouds loose_


You notice that I only recommended *"easing"* all the turnbuckles. 
You only *"disconnect"* them when you are ready and only, as I mentioned, singly or in pairs. One on each side at a time.
Sorry, I thought that was clear.
Since we are only talking about shrouds, not stays here, there is no problem removing both upper shrouds at the same time. Or both Aft lowers. Or the starboard aft lower and the port forward lower. 
You get the idea. Whether it's keel stepped or deck stepped, it makes no difference. As long as you have a couple of shrouds on each side holding the mast up, you're OK.

*The reason for easing the turnbuckles initially is simply to keep the mast more or less in column when you remove a shroud or two. *

I've had both uppers off and been hanging from a bosun's chair from the main halyard with both shrouds coiled and tied to the chair and about 20 lbs of tools while hanging from the main halyard. Lots of times. 
Although I usually, as mentioned, only take one of each off and duplicate it twice when making new shrouds. 
The point is, if you could take the mast and lay it on saw horses, you could support it in the middle and walk all the way out to the end and it wouldn't break. It's going to bounce like heck, but it's not going to break. 
Just like being up the mast on a Freedom or one of those freestanding Hunters. It's disconcerting, but hardly dangerous. 
And we aren't even talking about going aloft here. Just replacing chainplates.


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## jackytdunaway (Sep 11, 2006)

What i am trying to figure out is with a deck stepped mast and only a single chain plate on each side (the upper and lower both go to it) can i take both loose and leave only halyards to supprt the mast (along with the stays) while i rebed the chainplates


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## jackytdunaway (Sep 11, 2006)

i am bumping this back up. i really hope to hear from someone that has done this with a deck stepped mast


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## knothead (Apr 9, 2003)

jackytdunaway said:


> What i am trying to figure out is with a deck stepped mast and only a single chain plate on each side (the upper and lower both go to it) can i take both loose and leave only halyards to supprt the mast (along with the stays) while i rebed the chainplates


In a case such as yours where there is only one chainplate you must use halyards to support the mast. It's either that or just unstep the mast. 
What I do is hook up the halyards first. Then disconnect the upper shroud turnbuckle from the chainplate and hook it up temporarily to the toe rail, a midship cleat or something. It can even be lashed on. You don't want to load it up too much, but you don't need much just to hold the mast up. After you temporarily hook the upper back up, go ahead and remove the lower.


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## jackytdunaway (Sep 11, 2006)

Cool. So it sounds like it is not that hard to do. Thanks for all the input and advice


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## donlofland (Dec 8, 2008)

When I rebedded my lowers, I took them all off, one after another, did the "drill out the deck hole a size or two larger then fill the hole with epoxy and redrill it for the chainplate" thing, then rebedded each with 4200. I don't think it makes any difference if the (relatively flexible) mast is pulled a tad out of column as you loosen one lower shroud, then another, but you could always go around all the lowers loosening each turnbuckle a turn until they are all loose enough to disconnect. And counting the turns as you go would give you an idea where you want them when you put it all together again...

When I replaced the bulkhead to which the upper attaches, I first strung the halyard to the stanchion base near the upper shroud chainplate, then lossened and removed the shroud.


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