Fiberglass Repair...How Bad is It?

[DiverChick71]

First off, I'll say I'm new to boat work and ownership.

We pulled the headliner off of our Downeaster 38 last week to see how things looked underneath. We knocked down a lot of gunk. Around the big windows in the cabin, there is a lot of discoloration. I wasn't surprised, as this is a known issue with our boat. My question is...How bad is this? (See attached pics...the first two are around the windows and the white areas are where I pulled out staples. A third picture is discoloration around the screw for the companion entry.

It's not wet or soggy. There is no visible blistering around and nothing is visible from outside. It doesn't feel "soft". My guess is that water has entered around the windows and that the plywood core back there has water damage. And again my guess is that the fix involves digging out that damaged core, fill with epoxy, and rebed windows. How would experienced DIY'ers go about fixing this before replacing windows?

[skipmac]

From what I can tell from the pictures it does look like you have moisture in the core. If it is limited to the dark areas you see in the photos then I would do as you mention dig out the wet stuff and fill with epoxy. Looks like you can remove the window frames to expose the edge of the core.

Depending on the size of the wet areas and load it bears I would choose an appropriate thickener or maybe even build up layers of wood in the epoxy.

Do make sure the entire area is very dry before closing it up again. Open up the wet areas and leave open for as long as it takes. Maybe heat with a lamp (of course take care not to set the boat on fire ).

[DiverChick71]

Thanks. And I'll try to not set the boat on fire. I forgot to mention that given the size of the area, I planned on putting marine plywood coated in epoxy in as well. Is it possible that the fiberglass would be bad? My understanding is that the core is the problem, not the fiberglass, but someone else on another forum mentioned checking the fiberglass. We just had the boat hauled and there are no blisters anywhere, nor were there any blisters in a 2007 survey we saw.

[Krogensailor]

I would drill some 1/4" holes from the inside, not all the way through. I'd want to see the condition of the ply. You can probe with a pick to see if its soft or what have you. Plywoods outer veneers will discolr with minimal amounts of moisture, yet not be weakened. Also look into System Three Borate rods. Look for minimal invasive work before pulling things apart.

[skipmac]

Very unlikely the fiberglass is bad unless there is an area that was not properly done at the factory where it could be resin starved, voids left, etc. Otherwise it usually takes some kind of impact to damage the glass.

Krogensailor has a good point on minimally invasive/destructive examination of the areas to determine the extent of the moisture intrusion and potential damage to the plywood core. However, you do need to do something to prevent further water soaking into these areas which will probably require removing the window frames, screws or fittings in those areas anyway to stop future leaks. This should give you a good look at the edge of the core. If the edge isn't rotted or delaminated then drilling holes into the core further from the opening will dramatically speed the drying time and let you see how wet the core is in those areas.

The real belt and suspenders repair is to remove a little of the wood core around any holes and replace with thickened epoxy and then rebed the item that goes there. That way the core is completely sealed off in case the fitting leaks at all BUT still bed the fitting to keep the water out.

Mainesail (forum member) has an excellent tutorial on his website on how to seal deck fittings. Re-Bedding Deck Hardware Photo Gallery by Compass Marine at pbase.com
Are you familiar with butyl tape for this process? Great stuff. I have become a true believer. Mainesail's website tells you all about it and you can order it from him as well.

[tamicatana]

Here's some info from the source:
WEST SYSTEM | Use Guides

[beverley]

That was a great link on the Butyl tape. I have bookmarked it.

Thanks!

[DiverChick71]

Thanks all! I will have a good look at those links. I like minimally invasive for starters as well...and if it can be fixed thoroughly that way...all the better :-). Appreciate the info.

[skipmac]

Originally Posted by tamicatana

Here's some info from the source:
WEST SYSTEM | Use Guides

Great link. West Epoxy is a great source of technical help.

[Sandero]

If water got in... presumably it can be driven out... and then the assembly properly sealed against further infiltration. no?

[Tia Bu]

I'm looking at that and thinking Git Rot might be a good solution. You'd have to get the plywood dry, first. Maybe you could get the leak fixed, so no more water is coming in, then drill some holes through the fiberglass from the interior and let the whole thing dry for a few weeks. Then inject the Git Rot to restore structural integrity to the plywood. That would be minimally invasive.

I've done a lot of core repairs on decks. They're really not that hard. But you are right, I think, to start with minimally invasive attempts first. My first attempt, I yanked out the Skilsaw and cut off the top layer of fiberglass to do a full core transplant. This fixes the problem for sure, but it takes a LOT of fairing and sanding and painting to get the deck looking good afterwards.

[skipmac]

Originally Posted by Tia Bu

I'm looking at that and thinking Git Rot might be a good solution. You'd have to get the plywood dry, first. Maybe you could get the leak fixed, so no more water is coming in, then drill some holes through the fiberglass from the interior and let the whole thing dry for a few weeks. Then inject the Git Rot to restore structural integrity to the plywood. That would be minimally invasive.

Tried some Git-Rot on my house and a spot on the cabin sole where the PO let battery acid spill and rotted the wood. Ask me in 5-10 years and I'll let you know how it worked out.

[David_Old_Jersey]

Given you are starting out on the fun of messing around with bits of boat..........

TWO questions you should ask at the outset (of any job):

1) has the cause stopped?
2) is it structural?

For no.1 I am guessing the PO either fixed the leaking windows long ago - or you will be doing so! and for No.2 that your fix won't be structural (obviously important that it have rigidity into the sides - but nonetheless even if you "fixed" the problem with a tin of white paint (pre sale?!) the keel won't be falling off!).

In which case I would also treat it as an ideal way to get hands on with fibreglassing / Epoxy! Really not that hard to use, reading up and patience goes a long way - what makes these jobs ideal is that the results will not be structural and will be hidden from view so neatness of finish not a consideration!

So whilst the previous ideas have much merit me would be tempted to get the angle grinder out (or the Dremel!) to cut the fibreglass away and have a damned good looksee (and poke with a screwdriver).....if the plywood is rubbish chop out as far as needed (in depth and width and either scarf in a piece of plywood (saves on epoxy - $$). Scarf does not have to be neat (or even that close!) as will then use Epoxy filler to fix in place..........to finish off then simply need to lay on some layers of fibreglass / Epoxy (read up on how to do that and prepare the surrounding edges).....being out of sight means the patch does not have to be invisible / flush (although good practice to try doing that) and also IMO a good idea to start to learn how to use a disc sander gently (really shifts dried epoxy).......and if you want the results hidden then add a coat of white paint (I use bilge paint - including on the ceiling!). WHite paint likes hiding sins!

For those windows, what you may want to consider during replacement is fixing the edges (when the frames are removed), if open plywood at the hole edges then no surprise that water has crept along......my fix would be to scrape / drill out a 1/4 inch of even the good plywood and replace with Epoxy filler so that even if (when?!) a window frame does leak again that it "only" comes inside! Better than new!

LATE EDIT: Just re-read the OP, not sure whether window removal is going to be happening anyway - if the PO fixed the problem and windows don't actually leak anymore I would monitor the situation - and for that I would make sure the headlining could be easily dropped (in fixings = screws and in size of panels), likely find that useful anyway (cable runs / deck fittings).....and have a looksee every couple of years. or so .

[DiverChick71]

Sorry so slow...work is killing me. :-). I will research Git-Rot. The windows will be removed and fixed. The plywood is exposed (boo hiss) and that will have to be sealed or it's pointless to "fix" the offending area. When I pulled off one frame, there were actually several areas that had no problems, but the one with the pictures was the worst. There is an area on the bow that has to be re-cored and fixed, a pretty big area. So I'll get my chance to play with fiberglass. :-) My inclination around windows is still to dig out that whole area (with a dremel, wood chisel, etc) and dry then refill with marine plywood/epoxy. But I am not a dictatorship, unfortunately and boyfriend liked the drill out some plugs and see if it's wet. It honestly doesn't look wet from the outside or the edge. (i could see when window was pulled out.) The boat was in Florida til 2007 and then Guatemala for 2 years then here since 2010. It could be that it was fixed...or more likely that time just dried it out since our climate here is so much drier. Either way..on THAT section I'm pretty sure the leak was at the windows (SOURCE) and the fix is removing windows, replacing any rotted wood, re-sealing, and replacing windows. The windows are all crazed anyway. The bow however...yikes. It's going to be a doozy, I'm pretty sure. Maybe not difficult but time consuming and expensive for sure. On an up note...a week ago I didn't know the difference between roving and mat strand and so I'm learning lots of cool stuff. :-)

[DiverChick71]

I'm more worried about finding the source on the bow...