Page 1 of 1

Crack in DS2 cuddy entrance

PostPosted: Sat Apr 14, 2018 8:52 pm
by awrobatzek
Lower rim of cuddy entrance.JPG
Lower rim of cuddy entrance.JPG (238.4 KiB) Viewed 1315 times

I have ready through many threads about fiberglass repairs, but am unsure which method is right for this problem. This boat is new to me, and I am not sure how the previous owner caused this. The split seems fairly deep causing me to worry about putting this off and water getting down into it. Does this require fiberglass work, or would filling in the gap with something be sufficient? The new shape could potentially be a problem as I would like to add a door at some point.

Like I said, I have been reading through these forms for a while, but there are so many products out there that I am a bit lost on what to use.


Re: Crack in DS2 cuddy entrance

PostPosted: Sun Apr 15, 2018 4:09 am
by GreenLake
Not a critical repair in my book.

It's really not a place where water ingress is a problem (except perhaps from rain during storage) but you can drain the bilge.

Nice one to practice a bit of fiberglass work, though. So let's talk strategy.

You want to end up with a nice flat edge, so a door would fit against it, but it seems to me that retaining the "knife-edge" is misguided - the fact that it got damaged (most likely from dragging something out of the cuddy) doesn't recommend it as a design.

First, find a 2x4 and a large number of clamps. See whether clamping the damaged area will force it back into a straight line. If not, you would have to remove the damaged area and then rebuild it in place to get a straight line, not my preferred option, not least because you would have to do a bit of cosmetic work on the cockpit side -- always the lion's share of all such projects.

So, let's assume you can push the material back using clamps.

Now, I'm always in favor of any approaches that require the minimum in terms of wet layup in the boat -- that tends to always end up messier than planned.

You'll need some backing to stiffen the edge, not a 2x4, but perhaps a bit of 1/2" plywood (1/4" is too bendy). You'll need to do a bit of sanding with 40 grit to clear any paint etc off the backside of the damaged area. Next you tape off the area around the repair, including the cockpit facing side - I call it "front" side elsewhere - and wrap your 2x4 in wax paper or plastic - we'll need it for the clamping.

I would fill the crack itself with a bit of epoxy glue, like System Three GelMagic (or any other maker other than the twin-syringe hardware store brands). Thickened laminating epoxy would serve, if you have it, or have the microballoon thickening agent to mix it yourself.

Then you add the strip of 1/2" plywood on the inside, coated in laminating epoxy like System Three SilverTip (but you can also use the same glue, if you don't happen to have laminating epoxy). You want to coat that wood on ALL SIX SIDES without any gaps.

Clamp everything together with the wrapped 2x4 on the inside and perhaps another 2/4 on the outside. Wipe off excess epoxy. Repeat that process for a bit, because it will slowly drip and run for the first hour at least. Let everything sit overnight and remove the 2x4s.

While simply adding glue in the crack isn't going to restore the original strength of the laminate, we are adding strength with the new wood backing, and all the glue has to do is help it keep the unbowed shape. (During prep, you may have to peel a bit off the back end right below the crack line to expose a bit more surface area to glue the front part of the laminate to the wood backing; in the picture it looks like the crack line is only 1/8" of inch below the top. The length appears to be 4", over that distance an exposed strip of 1/4" would give you 1 square inch bonding surface, that ought to be enough if the wood backing takes all the strain.).

After everything has set up, and the clamping boards are removed, you need to check whether you need to retouch the epoxy coating of the wood, or fill any small voids were epoxy has run off between layers. Let sit overnight again, then sand and paint. (For the inside of the cuddy almost any paint will do, even a bit of spray paint - just as long as it blocks the UV from reaching the epoxy).

If you were not successful in forcing the damaged area into a straight line, you need to cut it out. You still provide the same wood backing, which you first glue in place as before. Then, with clamps removed, you need to rebuild the laminate (and the covering gel coat). More involved. Let's discuss that, when you've determined that it's the best option.

Re: Crack in DS2 cuddy entrance

PostPosted: Sun Apr 15, 2018 11:50 am
by awrobatzek
Thank you for the in depth reply, great info! I did some quick clamping, and I can get it back to about 90-95% original shape (possibly enough to sand the outside edge to 100% flat after). It requires a fair amount of force to close that crack and hold the shape, will epoxy alone hold it?

If you think that is close enough, I'll give the epoxy and reinforcement method a shot when the weather warms up. I have a workshop that I can can heat around 60 for small pieces, but outside temps are still in the 30's at night.

Re: Crack in DS2 cuddy entrance

PostPosted: Sun Apr 15, 2018 8:35 pm
by GreenLake
You can use SystemThree ColdCure if you feel your temps are going to be iffy. Need to mix that one with a thickening agent so it doesn't run. (Or: heat lamp, not too powerful, just enough to get he repair area at/above 70F).

Hard for me to be 100% sure, but my thinking was that you would get bonding between the layers of the crack by getting some non-runny epoxy in there first. (You would want to pry the crack apart a bit for inspection and getting glue in). On top of that, you should get bonding from along the part above the crack line directly to the backing wood.

Epoxy when it bonds well has considerable strength. I would be very surprised if you crack were to open up again.

The most likely cause for it, that I can come up, was that something was stuck when being dragged out of the cuddy. With a backing piece in that is level with the rim of the opening, that won't repeat. Another, more remote possibility is that something simply pulled asymmetrically due to some inherent tension in the various parts or because any loads from twisting/slamming the boat, or loading the cockpit floor weren't distributed well. In that case, it's possible that stiffening that edge on the inside might not be successful. Especially if the failure was due somehow to a failed bit of laminate (internal flaw).

However, in that case, you haven't lost anything. The new backing is still useful, but you would need to remove the failed laminate from the cockpit side and re-laminate it in place. So I see no downside of first attempting to glue the crack together.

Also, if you are getting the edge 90-95% straight, and the repair holds, think twice about the need to grind it to perfection, because suddenly you need to mess with gelcoat etc. to restore the surface. Better figure out a way how to make your door seal given a slight bulge. Car door gasket?