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sync 07-22-2010 04:32 AM

Cored deck soft spot repair
I know this has been asked here before, I did a search on this forum and many others but still have a few questions. Iím new to doing work on boats and I just recently moved into my í76 Catalina 27. I got the boat for a pretty good price and it seemed very solid. I also did have several people in the know (as far as boats are concerned) tell me the same.

I have been noticing a few smaller soft spots on the deck lately (forgive my terminology or lack there of) near the edge of the deck on the side where the mast stays are bolted down. I have one soft spot on the port side that is about 2-3 sqft and another in the same place on the starboard thatís about 1 sqft. Iíve been doing a lot of research about how to fix this. I am a bit concerned with the location of the spots due to the fact that my rigging is bolted there, which is most likely what caused it anyway (water seeping through the bolt holes.) I did notice that it looks like some glass work has been done in that area on the port side before so maybe its possible it wasn't done right the first time. Either way, Im planning on waterproofing all my bolt holes on deck when I figure out what Iím going to do about the soft spots.

Iíve read about the ďdrill and fillĒ options where you basically pump epoxy into the core but have found very few people actually advocating this. I know that injecting epoxy into a hole full of wet (Im assuming) plywood isnít going to solve anything, but I live aboard in a marina in the Tampa area, it rains a lot, and if I start cutting my deck apart to replace an entire section of core, I have no idea (whether being in a boat yard, or in my slip) how Iím going to keep everything dry. Im not even totally conviced I can do it myself. Im pretty handy but Im not completely sold on the idea of tearing into my deck. Is there anyone out there who has done this themselves or who has had success with the drill-and-fill method? Any thoughts at all? I am planning a haul out towards the end of the year (after the rainy seasion) so I could do the work while on the hard but it will all still be weather permitting.

Any advice or comments would be greatly appreciated.

CaptainForce 07-22-2010 05:20 AM

I would first suggest that the rigging attachments of your shrounds to the chainplates and the security of your chainplates is most important; however, the soft spots in your deck would be more of a cosmetic than a structural problem. I'm assuming your chainplates pass through this deck and are fast secured to structures beneath the deck. I have repaired several areas of my deck across the state from you, but also in rainy Florida. I far prefer the removal of the layer of fiberglass above the wet core and replacing the core. I used a rotary tool (like a Dremel) with a cutting wheel to remove the deck top layer and scraped out the sodden core. After this task, that can be completed in a couple hours, you can brush in a thin layer of epoxy to seal your work from the afternoon thunderstorm. After positioning your new core and grinding it to a level prepared for replacing your deck plate, you can again finish your morning work with a brushing of epoxy to seal for rain. Be sure to "feather" the seam at the perimeter of your repair to extend the surface area of the bond between your new deck surface and the old so that cracks won't develop outlining your repair. Take care and joy, Aythya crew

sync 07-22-2010 02:32 PM

Well, I have 3 side stays on that side, and all of them are in the area of the soft spot. They are bolted directly into the deck with a small piece of aluminum ( about 4 inches long) on the inside of the cabin as a backing plate. Ive looked at other setups of chain plates where they are built into the corner of the structure and mine are not light that. My deck is just glassed into the corner of the hull and I have a single timber support right under the mast that holds up the deck. My prime concern is that if the deck gets too soft, those stays might start to come up and then Ive got a full thickness problem. My second concern and the only reason I got this deep in thought about it, is if there is water in the core causing the delamination, its only a matter of time before it spreads across more of my deck. Am I right? I am perfectly comfortable in leaving it and writing it off as a causmetic issue if it doesn't get any worse. I just won't step there if I don't need to, but Im concerned that next year, theres going to be another square foot worth of soft and the job gets bigger.

I appreciate that you walked me through the job, that helps a lot. Thanks, I guess I just needed to hear from someone who's actually done it out in the elements. I know I can attach the stays to the toe rail to do the job and I will definitely make improvements to my chain plate situation when the job is done. I plan on painting the entire deck shortly after I finish the job.

You mentioned feathering out the finish to prevent cracking, but you never mentioned actually glassing over it after its done....Would you glass it or just epoxy it since Im basically just replacing the old glass back in its place? Also, as far as getting a new piece of core to fit, is there any trick to that? There is a slight curvature to the deck and I have a feeling that its not going to be the easiest thing in the world to get a brand new piece to just fit in nicely. Any thoughts on this?
Thanks a lot for all the info so far.

casioqv 07-22-2010 02:35 PM

I've had excellent luck using a "drill and fill" technique for soft decks on my 1974 Catalina 22. It's important to dry the deck core completely first- I was lucky and mine was already dried out. I've heard you can dry it out with many small holes, and displace some of the water with a solvent, like acetone.

On mine, I drilled a few holes, and glued film canisters over them with a hole drilled in the bottom- as funnels. I kept these full with unthickened west system epoxy, and pushed on the deck with my hands to "pump" the epoxy between the fiberglass and the wood core. After hardening, I removed the film canisters, chamfered the holes with a drill bit, and filled with gel-coat patch. It's been one year, and these parts of the deck feel more solid than the rest of the boat still.

casioqv 07-22-2010 02:42 PM


Originally Posted by sync (Post 624884)
You mentioned feathering out the finish to prevent cracking, but you never mentioned actually glassing over it after its done....Would you glass it or just epoxy it since Im basically just replacing the old glass back in its place?

If your deck core isn't rotted away or wet, but just delaminated from the fiberglass skin- then just filling with epoxy will be a permanent fix, without any glassing.

If the deck core has been left flexible long enough, the flexing can fatigue crack the fiberglass under and over the core. In this case, you'll need to re-enforce these cracks with new cloth, especially from underneath. On my C22, one of the cockpit benches would flex like 1" down when stood on, and I found the fiberglass underneath the core cracked through. After epoxying it back together, and covering the crack with new cloth from underneath, it's good as new.

ffiill 07-22-2010 03:07 PM

As an alternative filler consider either chopped glassfibre or chopped carbon fibre in resin which you can buy in large amounts quite cheaply from automobile repair supply shops. I have used the carbon fibre variety as a core when filling in a cut out in a sandwiched ply and glassfibre bulkhead.

sync 08-05-2010 10:51 AM

Awesome info....Ill look into the chopped glass and resin. Im sure my core is wet, before I do the repair, I need to fix a lot of improperly installed hardware on the deck thats been leaking. (Im almost positive its the chainplates leaking most of the water.) Anyone ever used CPES? Ive been reading about it and it seems like it works really well if the deck is dried completely. Also, Im planning to hollow out and make an epoxy bed around my chainplates so this doesn't happen again.

how big were the soft spots you fixed? I have a pretty large but narrow area, approx. 5 ft. x 1 ft. along the portlights where the port stays are bolted into the deck.

Im looking seriously into CPES but Im thinking it would be better, and not much more work or expense just to recore.....I just dont like the idea of cutting up my deck when Ive never worked with fiberglass before.

Thoughts anyone?

Wingnut247 03-03-2011 10:48 PM


How did your repair go?

I have recently purchased a 1974? Catalina 27. Guess what... a soft spot around the stanchion nearest the side stays. Fortunately it is small and contained to that area immediately around the stanchion. However, the proximity to the stays does concern me. The last owner lived aboard and did not sail or maintain the boat as she should have. It looks like the stanchion should have been re-bedded or at least sealed because it appears to have been leaking for a while. The soft spot appears to only extend about an inch maybe two from the base of the stanchion.

I am curious to hear about the experience, technique and results.

Anyone else with Catalina soft spot experience is welcome to chime in.

My previous boat (the one soon to head to craigslist) is a Catalina 22... love/d it... but I wanted a little more room inside.


Wingnut247 Washington State

travlin-easy 03-04-2011 10:41 AM

I have some wet spots on my 33 Morgan's deck near the mast boot. The boot is completely sealed, but nonetheless there are wet spots. I talked with a fiberglass repair guy at the marina who said he can fix the problem by drilling a few holes in the top of the cabin, then attaching a Hi-Vac to the lowest hole and over a period of a few days, draw the water from the balsa core. He then pours acetone into the highest hole while the Hi-Vac is still running and draws it through the core to finish the drying process. Next, he pours a very slow drying Epoxy into the highest hole, again while the Hi-Vac is still running. When the Epoxy resin reaches the Hi-Vac he shuts it down, waits about 4 days, then seals the fares the openings. He said the process essentially solidifies that portion of the core that was previously wet, adheres it tightly to the surrounding fiberglass, and does not add a significant amount of weight. No, it's not as good as new, but if everything goes well it should last about 20 years, which is longer than I'll probably be on Planet Earth.

Good luck, and keep us posted on how the repairs progress,

Gary :cool:

JKCatalina310 03-04-2011 11:30 AM

A couple of steps I would take
Congrats on the recent purchase. Good luck with her.

If it was me, here is what I would do:

1) The water coming into the deck is the first problem. This is likely leaking around penetrations for deck hardware (i.e. the bolts that hold down stanchions, cleats, jib tracks, chain plates, etc.). This is called "re-bedding" and is not uncommon; I have a 2001 Catalina 310 and I have to deal with this issue this spring. I would suggest you go to Maine Sail's site and searching these forums for details on how to do this.

2) If you core damage around the deck hardware, you should fix this before you re-bed the hardware. Again, not uncommon (I have this issue around one of my stanchions). And again I would recommend you look at Maine Sail's site and search the forums for details on how to do this. It is called "potting".

3) Then, if the deck damage is bad enough, look at the epoxy injection or core replacement.

Hope this helps.


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