Repairing cuddy roof stringers

[ctenidae]

You'll have the strongest foredeck in your fleet

Perfect for mounting my cannon. Avast, ye scurvy dogs!

[GreenLake]

Looks like you're all set, then. Post some pictures of your results.

Good luck!

[ctenidae]

So, laid in new fiberglass on the stringers. Filled the space between the two with polyurethane foam and laid 2 layers of chopped mat and 1 of woven. Hopefully will do the trick. I also made a mast guide that I need to attach to the deck hole to make stepping easier- my best piece of glasswork yet (formed it around the actual mast to get the shape and size right)

Also removed the board under the foredeck- interestingly, it wasn't 1 piece of wood that had cracked, it was 3 pieces just butted against each other, and the fiberglass (1 layer of light woven) had cracked at the unsupported joints. The board wasn't even attached to the deck, except by the glass.
Replacement board (1x6 red oak) has been cut and shaped, and will extend all the way into the point of the bow. Put two coats of poly on it, and will epoxy it to the deck, but haven't decided if it's worth it to glass it over as well. On the one hand, it's a tight space, but on the other glassing it in will help keep it dry (unless water seeps in through the deck cleat screwholes, in which case moisture is a bigger issue than if it's left uncovered).

I'll try to get some pictures that don't highlight just how bad my glass skills are...

[GreenLake]

You could simply coat your oak with epoxy - leaving out any glass. The advantage of such should be moisture seal, but be sure you don't drill into it w/o sealing the holes. A good laminating epoxy should be fine (for example, System Three's Clear Coat) but there are also penetrating epoxies as well (but unless you want to stock all of these, go for the laminating epoxy).

Wood/epoxy bonds, so I have read, are sensitive to the swelling caused by moisture, and can delaminate. Another reason why coating the wood is a good idea. (While under deck you won't have standing water, the worry with unprotected wood is about rain getting into deck openings and/or condensation during winter storage).

You should be able to treat the wood outside the boat and then glue it using the same laminating expoxy - following the epoxy makers instructions on whether you need to wash off any amine blush and/or sand the surface.

[ctenidae]

I ended up coating the whole board in resin, then glued it to the deck. To avoid delamination in the future, I also glassed in the ends. The foredeck cleat will also bolt through the board, so that should hold the middle. All in all, pretty happy with the results, though I haven't stood on the foredeck yet.

[GreenLake]

Make sure you thoroughly seal the holes for the bolts for the cleat.
For example:

• Drill a size larger, or two.
• Tape across bottom of the holes
• Fill with thickened epoxy.
• Drill the correct size.

Otherwise water can soak into your board from the fitting.

But you knew that already.

[ctenidae]

Thanks for the tip- I like the drill-it-bigger and fill-it-in idea. Hadn't thought of that one.

[GreenLake]

You're welcome and good luck. Let us know how it works out standing on your deck. I hope you'll get a very solid feel and no ominous cracking sounds...

[ctenidae]

http://picasaweb.google.com/alex.rogers/BoatPics#

Put some new pics up, couple of the foredeck support, others of painting.

As far as the work goes, 1-2 more coats of topside paint, and the remounting hardware, plus probably a zillion other small (ie large) projects, and she'll be ready to go in the water.

[Roger]

The original boats used foam as the basis of the stringers. You can replicate this easily (if you want to add a stringer; I would not) by cutting and shaping a piece of foam to size and soaking it into some fiberglass resin and hardner mix. Assuming you are repairing it with the boat upside down, gravity will be your friend by keeping your repair in place while you work. This might be a good idea to work with the boat upside down even if you are simply patching like the others on this thread have suggested. I would concur with their recommendations, especially the initial grinding and final feathering as it makes for a nice finish. If your were placing a new stringer in, then the wetted out foam will stay in place while you add wetted out layers of cloth over the foam. This is how the originals were made. A couple or three layers should be adequate. I would also grind out the crack, and patch it at least six inches to each side of the crack and a couple of inches to each edge of the rib or stringer.

The mast partner takes a lot of abuse, so I would add a layer there while I was at it. You can color your final layer of resin with gelcoat, to match the finish of your boat, thereby avoiding having to paint it.

[ctenidae]

Apparently Google has de-linked my pictures. I'll get around to uploading to my album eventually, but in the meantime, HERE are a whole bunch of pictures, some of which are referenced above.

https://picasaweb.google.com/alex.roger ... directlink

[Alan]

Alrighty, then. Cracked stringer photo as promised.

The foredeck flexes a tiny bit, so little that it's hard to distinguish between that and trailer movement. And there's no observable difference between the port side with the cracked stringers, and the starboard where they show no sign of cracking.The cuddy floor forward of the mast flexes a lot more, just for reference.

Seems to me that stringers that went all the way to the hull would be a lot stronger, but that would have meant more time and molding precision (i.e., money) in the assembly process. I could be tempted to fix that, once I find some spare time...

OK, it's late and I give up, after several attempts to post a thumbnail. It's in my personal gallery, for those interested.

[algonquin]

Alan - Personally I wouldn’t even classify them as cracks. Virtually no real loss of integrity. A little surface prep and duct tape
(I mean epoxy ) should take care of it. Brad

[GreenLake]

Alan,

I'm with Brad on this. I would go further and say that these seem to me to still be in the stage where I'd acknowledge their existence, but would not take action. Instead I would watch them for a season. If the cracks grow, it's still time to put an epoxy/fiberglass cloth patch on. If they don't grow, and if there's no cracking in the deck due to flexing, they may be benign. That's certainly my take on the smaller one in this picture.

[thumb=956]

The stringers don't go through. In that design, the edge of the deck must flex with load. However, that can make the end of the stringers a hard spot. It looks like the cracking (if stable) is serving the function of getting a more gentle load transfer. Adding a patch would make these points even more of a hard spot, hence my tendency to do a wait and see.

Looking at some other picture in your personal album, I see that your cuddy top has some bad cracks in a different spot (forward of the mast).

[thumb=855]

Have you done anything about them? They are in a curious location - what do you think is the cause?

[Alan]

Brad, GreenLake,

Thanks. Guess I'll have to find something else to worry about. And I can definitely find other things to do with the time.

Fortunately, the "cracks" in the cuddy top aren't really cracks (I checked just now; if I've only noticed the stringer cracks recently, who knows? - I could have missed cracks in the cuddy top as well). I think they're probably a couple of stray threads from the silver tarp in the photo.

GreenLake, I have your very good photo posting instructions from the DSII cuddy doors thread. They've worked just fine in the past, so I'm sure I'll be able to puzzle out what I was doing wrong last night.