Water in the cabin top core

[chiefaponte]

When I purchased my boat, over a year ago, I noticed that the bow pulpit was not very secured on a couple of the holddown plates. so I sealed it with a marine sealer and moved on; thinking to tackle that project in the furture.

Today removed the pulpit and found my balsa core under the aft port plate was water saturated. I removed about one inch of the rotted core into the fiberglass sandwich.

I left it open to allow it to evaporate as much as possible before I fill the entire void with Six10 epoxy.

I have walked the cabin top hundreds of time and neven noticed any soft or blistering fiberglass.

my concerns are:

what now?

does the water have any way to drain?

should I drill holes in the interior to provide drainage?

all sugestions are welcome.

 

[Calypso]

If you want to fix it correctly, remove the inside layer until you get to dry balsa, replace bad balsa, then epoxy it back on. Depends how long you want to keep the boat.

 

[chiefaponte]

I have an instruction book from West Systems that provides two alternatives.

first-it says to drill a 1" apart patterns on holes from the top, use a wetvac and fill holes wil epoxy

second-remove top skin and replace damaged core.

my problen right now is time. I am a navy officer due to deploy for six months in april and I do not think I have the time to do it right.

anyone has an idea of how much it would cost to have a boat yard do this work assuming I would have to replace 4 ft. sq.?

thanks

 

[BobM]

I don't think the swiss cheese it with holes an inch apart and fill approach really does much. My friend got a big price break on a 37 footer because a yard quoted 7000 to do a much smaller area than that, but it depends on your expectations. If it is the yards job from start to bristol finish it can cost a lot. If it isn't a structural issue I'd suggest fixing the areas under the pulpit mounts, backing them appropriately and then waiting to do it right later. In actuality I spend very little time leaning on the bow pulpit. From a safety perspective the stern pushpit is much more important to me.

 

[ewoden1]

Ah the joys of old boats!

Rotted balsa core at the mast step, I have a big hole in the deck right now and waiting for two days of warm weather to get the glassing done. I'm working from the outside in my case as the outside glass is trashed by the compression of the mast and quite frankly working upside down from the inside is a PITA for me.

Recommendation to work from the inside is a good one if you don't mind working from that angle. Select your resins for slow flow and you won't have a drippy mess. If working from the outside, if you are careful you can pop large areas of the outer skin off your boat if the core is really failing. By being strategic about making the cuts, you can preserve large areas of that "fantastic" feaux wood deck texture on the boat.

My step is a smooth glass area with a beveled transition. I can duplicate that no problem so cuting from the outside was a no brainer, given the sad state of the outside glass. I am gonna make it wider and longer than the original to accomodate an idea for a through-deck fitting for mast wiring. The trick will be getting some gelcoat to match the just slightly off-white color of the rest of the boat or painting thestep area with a matching color.

I agree with others, that vacuum extraction followed by injected high flow epoxy in a pattern of holes is usually a short-term measure. Wet balsa loses it's adherance for the glass sandwich, pumping in epoxy may be no guarantee that there will be good adhesion. Oh and some texts talk about flushing the wet area with acetone to solubilize the water, and then extracting the resultant mix under vacuum. I'm suspect about using an aggressive organic solvent around the old polystyrene composite and I am absolutely terrified at the prospect someone might do that with a non-explosion proof shopvac

 

[ewoden1]

Working from the inside on a 4 square foot area. You could do a respectble job in a day or two. Especially since it is Florida, lucky you. I'm with the first resonse, peel off the inside glass. Replace core material. Rebond the old inside glass. Smooth the transition. Trick will be leave enough of the inside glass near the hull deck nounting. Don't cut it all away at the edge of the deck as you are gonna need that integrity.

You are likely to reinstall the cabin mouse fir anyway, so your work will be covered. Just make sure the outer skin is not crazed at the mounting plates, and that you use something like butyl tape and camfered mounting holes to rebend the hardware to maintain water tight seals or you will just allow water back in.

 

[sailcruiser]

Run a normal household humidifier to help speed the process. Cover the holes with vinyl tape if the boat is exposed to the elements. Scrape all bad balsa out to dry, replace with chopped mat and epoxy, seal hardware with butyl tape and return to your normal activities. SC

 

[Calypso]

A dehumidifier would be good if working from inside. I would go from inside to preserve the gel coat. If the outside will need to be painted you might as well work from there and then paint. It would be easier.

 

[chiefaponte]

Yesterday I had a chance to put a "band aid" on this problem. I filled all the holes and voids with six10 epoxy and remounted the hardware. I also fabricated backing plates for the top and inside and sealed it with polysulfide. The funny thing is that my deck has no soft spots or obvious delamination. I believe the backing plates did the trick because the pulpit is solid. As you know S2 did not use backing plates at the pulpit. Photos attached

 

[BobM]

Looks pretty good to me. Should get you through a season or two. Never knew about the faux wood planking...that's a riot.

 

[ewoden1]

Looks pretty good to me. Should get you through a season or two. Never knew about the faux wood planking...that's a riot.

Ha not so much a riot when ya gotta work on that outside glass Ifigured I coul d spray down a section with mold release, lay a fram of one by's in a couple of food square and pour in some latex moulding compound. Peel it off and voila I've got a texture mold for when I ever want to duplicate that deck glass. Ha maybe I could sell 'em....though I imagine the market is rather small ;-)

 

[mark_swart]

What does the bow pulpit have to do with the cabin top? Did I miss something or did you just mean the foredeck?

I did that same repair on an O'day 23 about 10 years ago, it worked fine and the pulpit was solid years later when I sold the boat. I think you did the right thing. I probably wouldn't have even used the backing plates, unless the glass was cracked around them. Seal with 3M 4200.