Deck Repair Question

T

thompsdw

Member
Joined
Nov 29, 2003
RO Number
12507
Messages
57
Hi guys and gals. I have a '92 Wellcraft with a fiberglass overlayed wooden floor. I have noticed a very small area (during a carpet change job) where the floor is soft. Obviously the wood is softened or rotted below the fiberglass overlay. It is not bad enough to compromise the seal by cutting up the fiberglass to address the wood, however, I am not a fan of soft floors. Assuming that the wood is dry and rot halted, can a guy inject rigid foam and then epoxy seal the holes to repair softening like this? Is there any other solution versus cutting into the fiberglass overlay???
 
West System does a great job of describing this repair (and many others) in their book...

'Fiberglass Boat Repair & Maintenance' P/N 002-5500.

The procedure I remember for your type of repair is to drill several, small holes on the top side - DRY the core very well - and inject epoxy resin into the holes with a plastic syringe.

You can add a solvent to the resin to let it penetrate into wood better, but I'm not sure if it would be appropriate here, the core would probably be very porous already.

Good Luck!
 
You have to check for water. If it's wet, there's no cure until it gets dried out. The cure can get extremely involved so many people just live with it.
 
I am pretty sure that it is dry, but no so sure that there is wood below the fiberglass to strengthen. There was a hole through the fiberglass that had a foam plug I pulled out with my finger. I cannot feel a thick plywood deck under the fiberglass. This is like a boat detective - how the hell did they build this thing? That is why I had the idea of rigid foam. It would support the section between the hull and the fiberglass overlay and stiffen the floor. If I have too little wood to work with, that is the only option I can see versus cutting out a section of the floor.

I did purchase "Fiberglass Boat Repair" from West Systems.
 
Those holes are for pouring foam below decks. Also, if you have carpets and it gets wet, eventually, so will the foam or wood below the deck surface.

I dislike foam anywhere in boats because if it ever gets wet it will never dry out and any raw wood that's touching it will eventually get wet and rot.

You can fill the void with anything you want. One of our distinguished RO's found cement used to fill the void of his deck.(not a recommendation)
 
That is certainly what appears to be happening. The floor in that section is not solid, I believe most of the floor strength is coming from the fiberglass shell. I believe there is risk in cutting the fiberglass shell to access the wooden plywood, because I am just not certain what I will find (might not be enough wood to attach a filler patch to the deck). I am a capable woodworker, but if there is nothing there I am not certain what I would do because I loose the integrity that it currently has. Any other suggestions on filler that would expand and fill the entire void? Is my foam idea a bad one?

Question #2 - should be much more concerned about the overall integrity/rot of my wooden boat based on this finding? I have found wet (but never rotted) wood before.
 
you said glass over wood - not wood cored? if it is in fact glass over wood the drilling hole trick will not work, that only works to some extent (and luck) for cored areas. If you have glass over wood, my guess is the wood and glass may have separated, your foam idea to push up from underneath might work, but I'm not a fan of injecting it in an area that I can't see, and the moisture issue mentioned above.

If cored, cutting out and recoring with plywood blocks & resin is not that difficult
 
Bob, you could be right on the coring. All I have to make a determination at this point is what appears to be a foam filled hole. I can stick my finger down into the hole by at least 1" or more. Maybe that hole is a drill location down into the stringer and has nothing to do with the deck. I guess in that case I wouldn't feel the lower fiberglass layer. How could I tell what is on my boat? How would you repair a rotten core?
 
Sounds like you have a smaller boat and the plywood decking is what makes up the strength. The fiberglass is just supposed to be a covering to protect the wood. If that fiberglass covering of your deck doesn't have gelcoat covering it then that's all it is. Drill1 /4" holes around the soft area to find out the extent of the water intrusion. Ask the company to send you diagrams of the bulkheads and stringers. You can cut out the wet wood. You might be able to cut out a section between stringers/bulkheads, remove foam and sister in 2x4's along the stringers/bulkheads to support another deck section. And you get a chance to dry out any wet wood.

Pretty much what I had in my boat(1978 24' searay). All the wood in the aft half of the boat got wet and was rotten and had to be removed.
 
I'm not sure what the issue is here with cutting out a section and finding out for sure what the hell is wrong!
You're carpeting back ocer anyway right? Just cut a clean hole and make the hole capable of receiving and access hatch. Fix the issue, close the hatch, drop the carpet and you're done.
 
Well, this is the first wooden boat I have had. I don't have much experience in repairing, however, I am quite a woodworker. The section is in a crampt section of the boat (at jumpseat where you get into the boat wet - imagine that) and seems to stretch from sidewall to main stringer. I am wondering if I begin to cut, will I find a point where I can rabbit in a replacement pannel? I do not really want to add supports between stringers (just makes more holes). So, the answer to your question is that I am trying to plan before diving into a mess. I think the 1/4" drills are a good idea. So far, I am not finding foam below deck other than sealing the deck penetration. I really don't know what is below, but I believe Charlie is right. I don't think in a Wellcraft 20' runabout that the deck is cored. I think it is a skin. If it were cored, this would really be quite easy to fill between.

I do appreciate all the pre-planning help. I am going to do the right repair, but this may be my prelude to new boat this season. I have yet to find something that I cannot repair on a boat, but this seems kinda scarry how far it can go. All fiberglass has a lot less risk (but knowing what I would do, a hell of a lot more cost for a new one).
 
I've not had experience with deck repairs on older boats, but have seen problems with new boats that used expanding foam injected after the hull and deck were joined. A bit too much foam was injected and it pushed out a section of the bottom so it created a rocker near the transom. Created a champion porpoiser, nearly leaped out of the water at speed! Just be careful with foam in an enclosed area.
 
I don't know much about the construction of a '92 Wellcraft but I can offer that plywood is a good boat building material and it can be glassed to last almost forever. The problem is, not all boat builders are that careful. Any void in the fiberglass covering can result in the condition you have. Plywood wicks up moisture only a little slower than traditional hardwood and once the moisture is there, the spores grow into that we think of as rot.

If you decide to cut out the soft section, go further than what is obvious, maybe by 3 to 4 inches, all the way around. Developing rot isn't obvious in its early stages. I wouldn't rabbet in a patch, because that leaves too many edge surfaces, all of which can collect water over time. I'd tab in the replacement plywood piece after carefully coating it with good quality epoxy and letting it cure.

Whatever you do, it won't be a final cure. Some time in the future, some other spot will turn up soft. That's just a fact of life with boats that use gass over plywood and are put together quickly. But don't go crazy over this. Make the repair and enjoy your boat. With your careful eye, it will probably give you many years of fun on the water.
 
How about a 3/8 hole, bend a snake or even a coat hanger in there and twist it around? If you pop a seat out you might even find a pre drilled hole already there to try it. 1/2 ply? 3/4 ply?
Figure that out then short shank a jigsaw blade or roto saw to that depth then cut away. If you have a stud finder, run it all over the area. Wood floor I'm sure you'll find some screws. That's where your stringers are. If it's soft and gooshy, there's a good chance that spot is not sitting on a stringer. If it is that's a whole different issue.
 
Well, I did some investigative work tonight through the existing foam filled holes. I also have a stringer plan. The most significant damage is where wellcraft used wood screws throught the fiberglass cover to attach the rear transom wall to the deck. There is no foam hole there for injection and I haven't drilled it out yet. I used a borescope that I have with a 90 degree mirror. I popped out 4 injection plugs (what a stupid idea, they drilled through the fiberglass and used foam to seal the perforations. In several cases the foam plugs were hardened and loose in the drilled hole. Between the screws in the deck and the foam plugs (added to this is the side of the boat with the transom entry ladder - everyone wet into the boat) and it is no surprise where the deck rotted. Here is the interesting part. The plywood decking appears to be very thin in this area. I would say 1/2" max with some deterioration. I can feel and remove foam in multiple places. All wood is dry and foam does not appear to have moisture content. There is about 3/4" of air space between the foam and bottom of the plywood. An accelerated degree of rot is in place around the holes and screw locations (no surprise).

The decking damage is not even and is sporadic over about a 16" x 24" area. No surprise, thinnest at fastener locations or foam plug locations. It is definitely not cored. There is really only one stringer location anywhere around. Here is where I get a little weak legged on cutting through the deck. There are spots that are OK and spots that are not OK. Given the air space between the foam and ply, I am not sure that I will have a good area to attach the new decking to. There is not a good stringer area to attach to without my adding some cross braces. This is kind hard to explain, but I am concerned in this back boxed corner to find enough to get ahold of to patch the deck. If I drill a few holes and don't find residual moisture (remember, screw holes and foam plugs were allowing some drying effect) would polyurethane foam provide enough support to give me a stiff floor?

Now I know that this is not the "right" fix, but hell it is a $6,0000 boat and it is not our dream yacht. It won't last (in our house) more than a few more years (but I don't want to screw someone I sell it to either). Here is why I am wondering if this is OK. What I am seeing so far is that water has slowly passed the screws and plugs just enough to saturate the ply and cause it to deteriorate over time in a very localized fashion. What if it never made it to the foam as evidanced by my inspection in multiple locations.

So again, given the localized effect, I am wondering if the foam would fill the 3/4" void and provide enough support to stiffen the deck. And YES, I know part of this is justification, but I have a bad feeling about cutting out the deck in the absence of finding evidance of water in the foam. I still very much appreciate all of the dialog. I don't want you to think I am not listening, but I have a funny feeling about whipping out the rotozip.
 
Foam can be used to support a soft deck but it is a poor fix. Don't scare yourself from cutting out a section of deck. Stringers sections can be removed and replaced, too. I tried looking for some pics of my deck repair project but they're not showing up. If you need some to see whats involved, I think I still have some at photobucket.
 
Charlie, I would like to see the pictures if you can give me a link to them.
 
I have been there. I ripped out the entire floor on a 17 foot boat about 18 years ago. Ripped out most of the foam, encapsulated marine plywood in fiberglass and glassed it in. Also had a Wellcraft two years ago with a soft floor

I am going to go out on a limb here. Think about just going over top of the old floor with a new one. The underlying problem may still be there, but you may get another 10 years out of a new deck on top. The rest of the boat may just fall apart around it in that amount of time.
 
I bet you can find a nice access hatch 16x24 to close the sucker out after you cut out the section. Seal it up and carpet over it. The hatch might also provide a nice way to run wires and/or hoses for future up grades? I know. Cutting has a point of no return aspect to it.

If you do elect to cut. Make a ledge inside the cut out by attaching 4" 3/4 Starboard, then drop in a piece of 1/2 Pressure treated Ply. seal it or glass it then you're done
 
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