Ideas on repairing Cuddy crown

[Lil Maggie]

Howdy folks! Long time no post!
I have finally come to the point where can't delay this repair any longer. The rear edge of the cuddy on DS#2313, where the original rebar reinforcement has burst open the f/g due to internal rust. That rust, I'm sure was caused by water seeping through the holes on top of the cuddy where cleats for halyards/lifts were attached. This, if done properly (bedding compound) shouldn't be much of an issue, except the P.O. obviously didn't do that.

I'll post some pictures of the damage....

So, I'm looking for suggestions/ideas on how to tackle this. I have been collecting western red cedar strips from my workplace to possibly laminate a beam molded around the back lip of the cuddy, then glass it in place; has anyone tried this? I remember someone using empty paper towel rolls to reinforce the cuddy, but a quick search on this sub forum has left me empty...maybe I didn't look back enough?

Thanks for the advice ahead of time
Mike

[Lil Maggie]

The promised pictures...





CHeers
Mike

[GreenLake]

First, the bad news. Once the rebar starts to rust, the rust will continue to expand; I don't see a practical way to permanently halt that process. With the rebar "overhead" as a it is positioned, you can't even soak it in acid to attempt to get rid of the rust. I'm afraid that encapsulating it will not really prevent further deterioration. Also, the bulkiness of the rebar and inability to get to its upper / aft side where it touches the cuddy edge will mean that any treatment based on rust converter followed by encapsulation is likely to be doomed.

From a strength perspective, I think a hollow (or foam-filled) profile as deep as the cuddy lip and perhaps 2" wide might be strong enough, especially if you use biaxial or similar for the glass. Now it looks from the last photo as if the damage already extends to the exterior (there seem to be some vertical cracks in the aft face of the cuddy lid). That would argue for adding some laminate there as well.

The big question would be the best approach for removal and restoration of the cuddy edge.

You could remove the hardware, fill all holes and cracks to get the smooth surface on the outside, then coat in several layers of release agent and lay up a mold of the cuddy edge, say 4" wide. You could then, at your leisure, lay up a new cuddy edge that uses a hollow foam profile instead of the rebar, and once it has set up, you could cut out the entire old cuddy edge, and glue your new piece in its place. When you lay up the new piece, you can give it a "lip" that covers the connection from underneath.

This technique would require the least effort in removal (just cut out one large piece) and any layup is against a mold (or plug, for creating the mold). You would be doing the layup twice (you'd not use epoxy for the mold, but cheaper polyester and you could use glass mat for the mold).

All alternates require you to somehow get the rebar out without damaging the cuddy lip further. If something like a Dremel or a Fein multimaster allows you to cut cleanly between rebar and deck, then you can contemplate going that route.

Assuming you removed the entire rebar, you'd probably want to turn the boat upside down and suspend it on something so it's high enough for you to work underneath. You could lay up a foam-filled hollow shape in the "L" formed by the cuddy lip. The strength comes from there being two layers of glass when you are done that are 1" or so separated. One layer is the deck, and the other is the new layer on top of the foam. Together they form a beam (with the foam, the vertical face of the lip and the forward face all transmitting the shear forces). That kind of structure will be way stiffer than if you simply added a layer or two of glass where the rebar was.

Because of the cracks in the exterior aft face of the lip you need to either put some glass on the inside, or add some on the outside (which would require that you paint that area later and the repair may be visible (but it's easier to do; you could even run it a bit over the top edge to add a bit of strength there.

Final alternative would be to not worry about hiding your repair and simply lay up the reinforcements on the top of the cuddy crown (with a final layer of glass (or two) that wraps all the way around the lip to help cover the cracks and restore strength to that lip). In essence, such a repair would be similar to how the DSII cuddy is molded. It's crown extends upwards a bit, probably to gain extra strength?

Instead of a narrow rise right at the lip (as the DS2's have) you may want to make a strip that forms more of a 2-3" wide platform so you can re-mount your cleats there.

Instead of working with foam, you could use a strip of 1/4" or 1/2" plywood. That would allow you to drill out ahead of time the areas where you later want to mount hardware and to fill those with some epoxy/fiber mix or thickened epoxy before you cover with the outer layer of glass fabric. That way, when you drill the mounting holes, you don't drill into the plywood.

The plywood should still bend easily and you can glue it in place first and then laminate around it.

Here's a crude drawing.

Repair option, outside

CuddyTop.JPG (10.89 KiB) Viewed 24252 times

The last option would seem the easiest to build, but you will need to then paint it (to protect the epoxy from UV) and it will be a visible change. However, as the DS2's have that raised ridge there, your repair wouldn't be totally unlike anything found on some DaySailers.

Note that the DS class rules say: "No changes are permitted that modify the exterior lines of the hull, deck, or cuddy." If you are racing, you might need to get a waiver. Given that the DS2 has a raised ridge in that location, it would be tough to argue that making an exterior repair gives your boat a competitive edge. But, if that applies to you, I would contact the class measurer first.

[Lil Maggie]

I think any attempt to save the existing rebar is out of the question and it wasn't my plan at all. I may not even cut it out, but instead I was thinking of a laminated beam made of western red cedar to fit between the support jack and the cuddy on the inside. Sure the support would be transferred forward a few inches but that wouldn't be too bad (better than what I got now). the other would be, along with that beam, replace the edge rebar with a glass fiber rod, lay mat around the lip of the cuddy and fix the cracks on the outside to boot....got the rest of the summer to think about it...

[GreenLake]

I concur that you will need to remove the rebar due to the fact that if it is left in place it will expand as it continues to rust, and that will put further stress on the cuddy crown. The question is whether you can cleanly remove it from the inside, which would maintain the outer surface of the top and edge of the cuddy or whether you'll have to cut a bit of the deck out with it, and then deal with reconstructing that.

The cedar strips sound like an interesting approach. They should bendy enough that you can laminate them by clamping each directly to the inside of the deck and then build up sufficient layers that way. I think you have about 1.5" of space under the deck without encroaching on the opening. My guess is that 3/4" wide and 1.5" deep will make a strong enough beam to easily replace the contribution from the rebar.

You are right, in that placing that a few inches further forward shouldn't matter greatly. The edge is pretty strong on its own, but not strong enough to hold the weight of someone stepping on the deck, that's what the beam is for. Because you are adding a cedar beam, there's no need for a fiber rod, but 2-3 layers of cloth on the inside corner (after taking out the rebar) might not go amiss to stabilize it (esp. given the cracks).

The thing about mat is that it's great for a first layer when the substrate is rough, but -- unless you buy mat especially designed to be used with epoxy resin, the binders in the mat require the chemicals in the polyester resin to dissolve. And because your repair is against an already cured deck surface, it's usually thought better to use epoxy resin because it is the better glue and because it doesn't shrink while curing. (That said, I believe I've used the "wrong" resin for the mat on occasion and not observed any ill effects).

Alternative to laminating a wooden beam you might get away with an approximately 1" diameter hollow tube nestled into the corner where you cut out the rebar. It's OK for the tube to be somewhat flexible, in fact you'd want that to more easily place it. For strength, you'd add several layers of cloth on the inside, about as much laminate as the deck. By separating the two layers of laminate by the diameter of the tube, you'd create strength way in excess of the strength of the tube material on its own. Something as simple as PVC conduit would probably do the trick.

You can nestle it in the corner where you cut out the rebar, or you could place it where you planned the cedar beam to go. There's 6" cloth tape with mat backing sold by West System (it didn't say that it's for epoxy, but given the vendor it would seem likely). 2-3 layers of that would probably give you enough laminate and 6" width might just be enough for the job. That might be both cheaper and easier than a wooden beam.

To be stiff, a structure doesn't need to be solid.

[Lil Maggie]

Alternative to laminating a wooden beam you might get away with an approximately 1" diameter hollow tube nestled into the corner where you cut out the rebar. It's OK for the tube to be somewhat flexible, in fact you'd want that to more easily place it. For strength, you'd add several layers of cloth on the inside, about as much laminate as the deck. By separating the two layers of laminate by the diameter of the tube, you'd create strength way in excess of the strength of the tube material on its own. Something as simple as PVC conduit would probably do the trick.

You can nestle it in the corner where you cut out the rebar, or you could place it where you planned the cedar beam to go. There's 6" cloth tape with mat backing sold by West System (it didn't say that it's for epoxy, but given the vendor it would seem likely). 2-3 layers of that would probably give you enough laminate and 6" width might just be enough for the job. That might be both cheaper and easier than a wooden beam.

I really like the PVC idea!...1/2 PVC would work just fine....as for the laminate beam, in my case I already have a bunch of western red and white cedar strips that I got from free scraps at work; but it is true that if I do the cedar think I won't necessarily need to do anything but a few layers of tape/mat over the removed rebar end. I can easily cut that out with an angle grinder (which I already have), clean it out and lay it with epoxy and use wax paper/masking tape to keep the f/g tape repair tight against the cuddy lip....oooh! I am liking this! AND, adding the 1/2" pvc conduit in there will not only be a cheap but effective; turning that lip into a brick-you-know-what house!

I like it!

[GreenLake]

Sounds like you are all set.

[Lil Maggie]

Started to clean out the rebar today....and cut the first strips of W.R. cedar to fit the cuddy. I think I'll stick with the laminated wood beam and just f/g tape over the inside edge where the old rebar was )I'm not quite done cutting the ends toward the cuddy sides and right over the middle, where I'll need a reciprocating saw from work to finish. Once that is done I'm grinding the inside of the cuddy edge smooth and laying a couple of layers of f/g cloth tape over that and over the beam (once in place)

M

[GreenLake]

Hope you'll share some pix with us of your progress.

[Lil Maggie]

Hope you'll share some pix with us of your progress.

Well Greenlake...if you insist:

First the cutting of the rebar off...harder than it looks and it took an angle grinder with a cutting disk AND an oscillating saw for those hard to reach places




once out, I ground the rebar pocket smooth and plan to stuff it with a little pool-noodle foam, then the f/g cloth over it...or just the cloth, because the beam is massive!





Once dry I'm sanding it smooth and radiusing the edges prior to a saturating coat and when still tacky, then the cloth commeth!

Materials used:
1-1/2" x 3/8" western red cedar strips (4 layers)
West system epoxy and "regular" hardner
60 and 80 grit sand paper

Vacuumed and blew off what seemed like endless f/g dust and rust flakes off the old rebar....more tomorrow

[GreenLake]

You'll be able to host a hippo dance convention on that cuddy deck when done.

[fatjackdurham]

I was noticing your rigging in the one of the first pictures. It looks like you have it totally set up for solo sailing. When finish the repair, could you post a photo of the setup with notes on how you did it?

[carl10579]

I have an old cheaply built Chrysler boat that used the "paper towel" rolls for under deck re-enforcement. It was a cardboard tube cut in half lengthwise and lay'd on round side out and then glassed over. It worked okay I guess but in time they started to peal away. I think the wood would be stronger. Glue it up, cut it to fit, paint it with resin and hardener and epoxy putty it in place then glass it over. There are more sophisticated ways to make the repair. Check the video's on http://www.fibreglast.com/.

My DS1 (which is gone) and my DS2 both have cracks and they look like they could have come from the mast leveraging between the tabernacle and the cuddy edge while unsupported.

Good luck.

[GreenLake]

Carl, the purpose of a "paper tube" in this kind of repair is only ever to provide "scaffolding" for the laminate until it cures. (It would still be useful to saturate it with resin, so that it can remain in place without rotting). If the laminate peels off the surface, then I'd normally suspect poor surface prep as the culprit. Perhaps the underside of the cuddy wasn't cleaned or sanded well enough. It's also possible that whoever did the repair did not use enough layers - the strength of the hollow stringer ultimately comes from a combination of geometry and wall thickness.

The depth and width are given by the tube, and "paper towel" implies a reasonable diameter. I'd be surprised if this application required much more than 1/16". That's just 3-4 layers of cloth...

The tricky part of the layup comes from where the walls of your tube meet the deck at 90 degrees. That turn may be too tight for the laminate unless you fillet it first.

[Lil Maggie]

Ok...the beam has been faired, sanded, saturated in epoxy and glassed in...and the old groove where the rebar used to live has been glassed over as well. The cam cleats were relocated farther forward (the old holes filled and painted over)....some images:








Not the greatest glass job but it'll do...I cut off a lot of bubbles and did a fair amount of sanding...this one is definitely getting painted over!.....but the test: I put my 230 lbs right over the edge of the cuddy and didn't even creak!..Not quite a hippo dance party but it'll do