Fly bridge soft core

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Bay Retriever

Senior Member
Joined
Oct 13, 2019
Messages
150
Location
USA
Vessel Name
Bay Retriever
Vessel Make
2004 Mainship 400
I recently purchased a 2004 MS 400 Trawler that I knew had soft core issues on the fly bridge deck. The flybridge deck is now exposed and the moisture seems to be coming in from somewhere in the front of the flybridge on the port side. Apparently, the rotten core goes underneath the seats.

Has anyone ever experienced moisture coming from the front of the flybridge? I have not yet seen the boat as I am traveling and will see if later this week to personally inspect and discuss with my Marina and Fiberglass techs the options and cost estimates for finishing the repair. The moisture has reportedly wicked from the port side of the helm station and runs front to back with the softest areas from just behind the Captain’s Chair towards the entry way at the top of the stairs.
 
Have not had any experience with that boat but if it were mine, I would keep pulling things off until you reach the entry point for the water. It could be any point that a hole was drilled into the flybridge deck. Manufacturers don’t do well when they bed fittings. Suggest you go to Compass Marine website and read his articles on bedding fittings.
 
I recently purchased a 2004 MS 400 Trawler that I knew had soft core issues on the fly bridge deck. The flybridge deck is now exposed and the moisture seems to be coming in from somewhere in the front of the flybridge on the port side. Apparently, the rotten core goes underneath the seats.

Has anyone ever experienced moisture coming from the front of the flybridge? I have not yet seen the boat as I am traveling and will see if later this week to personally inspect and discuss with my Marina and Fiberglass techs the options and cost estimates for finishing the repair. The moisture has reportedly wicked from the port side of the helm station and runs front to back with the softest areas from just behind the Captain’s Chair towards the entry way at the top of the stairs.



Here are some pics of the fly bridge that has been opened up.
IMG_1889.jpgIMG_1890.jpgIMG_1891.jpgIMG_1892.jpg
 
Is that your boat TMac? That's way worse than my problem. In my case it didn't see to wick to port like yours did. It was confined to a rough rectangle going from aft of the helm seat back to the top of the stairs, about 18-20 inches wide. My repair guy felt that the holes for the screws that hold the base of the table were the entry point for the water. In my case the PO didn't have a full enclosures, no windows, just a bimini top so any rain that wasn't vertical would wash down the upper deck. He also explained to me that he has seen decks get water saturated just from hosing it off to clean it.

Once you get this done it should last for quite a while. Ask your guy to epoxy the screw holes for the table and also for the stanchion on the left at the top of the stairs, as Mainship didn't bed those screws at the factory.
 

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Yup. That’s my flybridge all excavated. Hope to see it first hand on Thursday. Would like to get to the source so I feel better about spending all this Mula!
 
Where are you having it done?
 
Wow, that is a lot of area that was removed. When it is all reglassed, make sure that they bed all the fittings properly so it does not happen again. They should reef out the core around every hole they drill and fill with thickened epoxy and then drill the epoxy for the screw or bolt. They should bevel every hole so that the bedding can form an O ring around the screw or bolt. Check Compass Marine web site for the correct process.
 
Moisture

I am in the process of purchasing a MS 400, 2004 as well. The Surveyor reported that he detected some moisture around the radar mast on the flybridge and in the cockpit area near the transom door but the areas are not spongy or soft.
Is it acceptable to seal the areas of water intrusion without doing any other work to get the moisture out of the deck? Will it dry out on it's own once the source of moisture is eliminated?
 
I am in the process of purchasing a MS 400, 2004 as well. The Surveyor reported that he detected some moisture around the radar mast on the flybridge and in the cockpit area near the transom door but the areas are not spongy or soft.

Is it acceptable to seal the areas of water intrusion without doing any other work to get the moisture out of the deck? Will it dry out on it's own once the source of moisture is eliminated?



Captain Mike,

Based on what I have learned, I would make sure you really want the boat taking into consideration all the updates done or not done by prior owners. What I am finding out is that Mainship did not do a good job laying up the fiberglass, particularly on fly bridge.

My repairs are ongoing and more extensive than I had estimated. The moisture damage we are finding seems to be related to areas around and protruding downhill from every screw-based fitting.

We have ripped off almost all of fiberglass in the seating area under the Bimini and are now examining the area close to the stairs and hope to find an end to the wet core soon.

Everyone tells me that if you leave it unfixed, eventually it will totally fail and crack. Also, make sure you take up all the screws and inspect the areas around/below IMG_1903.jpgIMG_1905.jpgIMG_1907.jpgIMG_1911.jpgIMG_1912.jpgAdjustments.jpgIMG_1929.jpgand reseat them using a strong sealant.
 
Capt Mike, I have to say my experience is not as bad as Bay Retriever and I don't feel the lay-up was deficient. The problem I had seemed to be related to the screw penetrations in the upper deck and these were not adequately sealed.

There are probably others who know more than me about this, but to answer your question, I don't think the moisture will go away after the source has been sealed. A better approach might be to protect the area from moisture for a period of time to let it dry out and then seal it up. Any boat you look at that is 15 years old will probably have some moisture showing up and that doesn't mean it is a major problem. Keeping additional moisture out would be a good thing, however, so you should build that cost into your offer.
 
I don’t think the moisture will go away either. If it is not a large area I have seen some people drill some holes and hook up a shop vac and run it for several days to help dry it out. They drilled and tapped the fiberglass and made a manifold for the vac to hook to. After the area was dry then fill the holes and repair the finish. Not as good a repair as cutting out the fiberglass and replacing the core but may work if the problem isn’t large. Then reseal every penetration in the deck. Reef out the core and fill with thickened epoxy per Compass Marine web site.
 
Depending on how wet, a vacuum setup may work. Personally, I'd use a vacuum pump and catch tank hooked to fittings in the deck, rather than a shop vac. And let it run for a while. Ideally you pull from as close to the intrusion point as possible and if water could migrate to get in, it should migrate and evaporate to get out.
 
This is an interesting thread to me as I once owned a 1978 Mainship model 1.
It also had core damage that I repaired myself.
When at the Mainship factory in 2000 (I think) we were told by Mainship chief engineer that the current layup process and materials would eliminate any core problems.
Of course we experienced Mainshippers just laughed at that.
We knew that all the soft flybridge deck issues were because the boats were shipped without the flybridge attached and the dealers didn't take the time to properly caulk everything that was installed at their location.
It's a shame really.
It will be better than new once it's all repaired. I know mine was.
 
Capt Mike, I have to say my experience is not as bad as Bay Retriever and I don't feel the lay-up was deficient. The problem I had seemed to be related to the screw penetrations in the upper deck and these were not adequately sealed.

There are probably others who know more than me about this, but to answer your question, I don't think the moisture will go away after the source has been sealed. A better approach might be to protect the area from moisture for a period of time to let it dry out and then seal it up. Any boat you look at that is 15 years old will probably have some moisture showing up and that doesn't mean it is a major problem. Keeping additional moisture out would be a good thing, however, so you should build that cost into your offer.


As most east coasters know, we had some snotty weather pass through last night. Unfortunately, the fly bridge repairs took a hit and water pooled on the fly bridge temporary cover and made its way into the Salon through the ceiling. The water dripped through the headliner in the aft port corner of the salon.

Hoping to get the fly bridge fully enclosed or at least tented within 24 hours before the next weather system passes through Mobjack Bay tomorrow night.

My questions are/does anyone know:
1. If there a bulkhead on the sun deck behind the mast that leads/forces water that’s in the core towards the aft-port corner of the salon ceiling?
2. Now that water has penetrated the salon ceiling, what’s the next step? Should we remove the fiberglass deck behind the summer cooking station?

I’ve attached two pics: one showing the water pooled on the fly bridge temporary cover and another showing water on the floor of the port side aft corner to the salon.

Any suggestions will be appreciated.

IMG_1979.jpg
IMG_1980.jpg
 
TMac, sorry to hear about your calamity. Here are my thoughts:

Firstly, my repair guy Mark explained to me that there was a rib running side to side in the area just to the top of the stairs, roughly where I marked your photo. He told me that was all that prevented the entire top deck on my MS from becoming completely waterlogged. Based on your issue, it appears that the rib may not run all the way to the port side by the summer kitchen and thus allowed the water to flow back to the rib, then to port, and subsequently back to the aft corner. If it were me, I would not tear up that area if isn't soft. I don't think a one-time shot of water is going to do lasting damage, and, as long as you tent it, it bet it will dry out sufficiently.

Also, here's a link to the Stella Blue web page showing what it looks like above the vinyl ceiling, in the event you have to get up there to dry something out.

"www.scyr.org/stellablue/headliner2.htm"

Are you going to have your guy replace the diamond non-skid? On mine Mark just sanded off the diamond pattern and applied a sand texture non-skid for a lot less money. It looks factory and even cleans easier than the diamond stuff.

Good Luck!
 

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We have one of the first 350's, hull #32, a 1997. No issues at all with soft decks, flybridge or otherwise. Our boat never was shipped, so the bridge was never detached, and has had a full enclosure since new. Been in our family since new.

Sorry to hear about your issues, I hope it all works out for you. Love our Mainship and I'm sure you do too.
 
I recently purchased a 2004 MS 400 Trawler that I knew had soft core issues on the fly bridge deck. The flybridge deck is now exposed and the moisture seems to be coming in from somewhere in the front of the flybridge on the port side. Apparently, the rotten core goes underneath the seats.

Has anyone ever experienced moisture coming from the front of the flybridge? I have not yet seen the boat as I am traveling and will see if later this week to personally inspect and discuss with my Marina and Fiberglass techs the options and cost estimates for finishing the repair. The moisture has reportedly wicked from the port side of the helm station and runs front to back with the softest areas from just behind the Captain’s Chair towards the entry way at the top of the stairs.


Mine was fixed before I got it. But the entry for the water was the bolts that held the helm seat to the deck. Easy to understand.....and fix by just doing a better job of bedding the seat.
 
I'll take every opportunity I can to remind TF readers of this simple truism where cored composite is concerned, never rely on caulk, sealant, bedding etc to keep water out of cored structures. Caulk is a temporary affair, it dries out and fails, sometimes in a year, sometimes in 7 or 10 years, but in most deck cases it eventually will leak.

This article goes into some detail on the subject. https://stevedmarineconsulting.com/cored-composite-deck-hardware/

(Attending the Marine Equipment Trade Show, Amsterdam, the Netherlands)
 
TMac, sorry to hear about your calamity. Here are my thoughts:



Firstly, my repair guy Mark explained to me that there was a rib running side to side in the area just to the top of the stairs, roughly where I marked your photo. He told me that was all that prevented the entire top deck on my MS from becoming completely waterlogged. Based on your issue, it appears that the rib may not run all the way to the port side by the summer kitchen and thus allowed the water to flow back to the rib, then to port, and subsequently back to the aft corner. If it were me, I would not tear up that area if isn't soft. I don't think a one-time shot of water is going to do lasting damage, and, as long as you tent it, it bet it will dry out sufficiently.



Also, here's a link to the Stella Blue web page showing what it looks like above the vinyl ceiling, in the event you have to get up there to dry something out.



"www.scyr.org/stellablue/headliner2.htm"



Are you going to have your guy replace the diamond non-skid? On mine Mark just sanded off the diamond pattern and applied a sand texture non-skid for a lot less money. It looks factory and even cleans easier than the diamond stuff.



Good Luck!



We found the source for the water penetrating the headliner in the salon (port side). Water made its way into the seat compartments on the fly bridge during the heavy rain/snow we had a week ago here on Mobjack Bay.

Below is a picture of the drain hole inside the seat compartment. Water penetrated between the outer fly bridge skin and the inner seat compartment skin. My fiberglass technicians plan to reseal the drain hole so it doesn’t happen again.
 

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Bay Retriever: what are you going to do about accessing core under the fibreglass furniture ? Also, if your deck has white painted perimeter edges and boundaries which are free from non skid, when the upper deck layer is removed do they stand off those smooth boundary borders or cut them out with the rest of the top layer ?
 
Bay Retriever: what are you going to do about accessing core under the fibreglass furniture ? Also, if your deck has white painted perimeter edges and boundaries which are free from non skid, when the upper deck layer is removed do they stand off those smooth boundary borders or cut them out with the rest of the top layer ?



The core material under the fiberglass furniture will not be excavated because not much moisture damage was found. Also, the smooth transition boundary borders around the furniture bases will be sanded down and beveled into to fiberglass skin that’s being reused.
 
. Also, the smooth transition boundary borders around the furniture bases will be sanded down and beveled into to fiberglass skin that’s being reused.

Will those smooth boundary borders be preserved and repainted or will they disappear under the new non skid?
 
We found the source for the water penetrating the headliner in the salon (port side). Water made its way into the seat compartments on the fly bridge during the heavy rain/snow we had a week ago here on Mobjack Bay.

Below is a picture of the drain hole inside the seat compartment. Water penetrated between the outer fly bridge skin and the inner seat compartment skin. My fiberglass technicians plan to reseal the drain hole so it doesn’t happen again.

That's good to know, even though I have a full enclosure up there I think I'll try to seal those drain holes as well.
 
Will those smooth boundary borders be preserved and repainted or will they disappear under the new non skid?



We are using the old skin as It’s in pretty good shape. I checked with other repair yards. The technique for reusing the fly bridge skin is becoming more and more common. Some fiber glass techs still prefer to lay new fiberglass and put down a new non skid pattern. In my case, most of the old non skid will be used as is. In certain areas, like the entry way, new transition seams will be created based on the fact that some of the old fiberglass skin has to be replaced and the non skid will be repatterned using the same Mainship diamond pattern.
 
Y'all are scaring the crap out of me. What warning signs did you get that you were having core issues? Ours checked out fine with a moisture meter (which I know aren't infallible) when we bought it in 2013. I haven't worried about it much since.


I'm thinking I'll pull up the rail from around the stairs and epoxy/rebed the screws with butul tape. When you are talking about the table do you mean the table in the main part of the FB or the small table on the aft FB deck?


Thanks.
 
Probably the only warning will be a wet core. No real good way to tell it is happening until it is too late. Maybe an infrared camera will show the moisture but if it shows moisture it is probably too late. I would take all the screws and fittings loose and epoxy fill the holes and redrill and bed with butyl. Better do a small bedding job before it turns into a giant job of recoring.
 
Y'all are scaring the crap out of me. What warning signs did you get that you were having core issues? Ours checked out fine with a moisture meter (which I know aren't infallible) when we bought it in 2013. I haven't worried about it much since.


I'm thinking I'll pull up the rail from around the stairs and epoxy/rebed the screws with butul tape. When you are talking about the table do you mean the table in the main part of the FB or the small table on the aft FB deck?


Thanks.



The FB table had been taken out by a prior owner. It is now obvious that the screws holding the table down was the source of moisture getting into the fly bridge core and ultimately rotted out the FB entry way all the way back to the stairs.

The table on the sun deck was spared moisture damage as the water could not thankfully travel past the stairs because there is a “fiberglass bulkhead” just behind the mast.
 
Y'all are scaring the crap out of me. What warning signs did you get that you were having core issues? Ours checked out fine with a moisture meter (which I know aren't infallible) when we bought it in 2013. I haven't worried about it much since.


I'm thinking I'll pull up the rail from around the stairs and epoxy/rebed the screws with butul tape. When you are talking about the table do you mean the table in the main part of the FB or the small table on the aft FB deck?


Thanks.

Doug, my glass guy said it was from the folding table was screwed to the floor. Apparently they just screwed through the skin into the balsa. He epoxied it real well when he did the repairs. He also said the stanchion at the top of the stairs had the same problem. It can't hurt to bed all the penetrations on the upper deck including the round table. If you have the time and skill to do so, I would follow Steve D'Antonio's process and the deck should never have a problem, at least from those water sources.
 
When you say he epoxied it real well, did he reef out the coring and fill with thickened epoxy?
 
I'll take every opportunity I can to remind TF readers of this simple truism where cored composite is concerned, never rely on caulk, sealant, bedding etc to keep water out of cored structures. Caulk is a temporary affair, it dries out and fails, sometimes in a year, sometimes in 7 or 10 years, but in most deck cases it eventually will leak.

This article goes into some detail on the subject. https://stevedmarineconsulting.com/cored-composite-deck-hardware/

(Attending the Marine Equipment Trade Show, Amsterdam, the Netherlands)

Hi Steve. Thanks so much for your thorough article regarding composite deck hardware, hardware bedding, coring, etc. Much good stuff here!

Regards,

Pete
 
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