Scupper Styles-- Long Term Feedback?

[Dave-in-RI]

I need to restore function to my 2010 Sun Cat scuppers; they're the original rubber flaps which have turned up. I've read everything here, watched some videos online, and scoured various reviews on product sites. What I'm hoping to find now is some anecdotal feedback on various styles. On my Picnic Cat, you had to put plugs in for practical sailing. I don't want to do that on the Sun Cat; I want better-working yet self-draining scuppers.

Here are the options:

1) Turn the curled-up rubber ones around so they curl inward / seal again. I've read you can keep doing this.

2) Replace rubber flaps with new of the same style.

3) Replace rubber flaps with hard plastic flaps of this style (can be bought w/ or without the rings, and in white or black):
https://www.hopkins-carter.com/thmaflmoscva.html
https://www.wholesalemarine.com/t-h-marine-scupper-repair-kit/
https://www.wholesalemarine.com/th-marine-flush-mount-scupper-adapter.html

4) Replace rubber flaps with ping pong / flomax style:
https://www.wholesalemarine.com/t-h-marine-flow-max-ball-scupper/?gclid=EAIaIQobChMI1cjmmMzP6QIVGcDICh0XtgAqEAQYBSABEgJMLvD_BwE

5) Replace rubber flaps with duckbill style:
https://www.wholesalemarine.com/th-marine-duckbill-overboard-drain-scupper.html


The various styles have pros and cons each. For the well above-waterline cockpit draining, speed and volume are most important, so I'll try flipping the rubber ones around first. For the lower / waterline ones, I've read the ping pong ones are noisy while sleeping on the boat (not something I plan to do often) and that they can let water in while underway above certain speeds. For the duckbill ones, i've read that the bills can come with sloppy manufacturing tolerances that are hard to check or trust, but they are generally the most one-way-value style available. They're not fast draining, either. I'm not sure if the hard plastic flaps would form as tight a seal as a rubber one, though they claim to (and once the rubber hardens, it's more plastic than gasket anyways). Aesthetically, to my eyes, the OEM rubber flaps-- or the hard plastic flaps-- are the most attractive, then ping pong, with duckbill last. But, when it comes to holes in a boat, function beats form.

Prices are cheap enough for these things where it doesn't matter to me, I just want the "best" option, if there is one.

I also can't get a handle on whether you're supposed to add sealant-- and what kind-- to these when you replace them (or flip the originals around so they curl up toward the transom). Sealant sounds like it makes sense, but is it necessary or would it just goop things up for next time around? Or do you just add some into the screw holes like this (vs "caulking around it" like a bath fitting): https://www.boatus.com/expert-advice/expert-advice-archive/2013/october/how-to-install-a-one-way-scupper-valve

Thank you.

Dave

[bruce]

I don't know how common the problem that we see on the PC of water entering the scuppers is on the SC, or the pitch of the drainage tube for the water to get up to the cockpit. The rubber flaps on my new PC never did their job and I replaced mine the first season with the T-H ball scuppers that have worked very well. The fastener holes matched perfectly.

To your options:
1) The rubber has curled and is no longer flat. The plastic seat is still flat. I don't see this sealing much better.

2) New rubber will help, but mine were never effective even when new. How critical this is on the SC I don't know.

3) I don't see how hard plastic will seal better than rubber. Both seem better suited to resisting a surge of water with some pressure. Without any pressure on the seal I think it will leak.

4) The ball scuppers use a soft silicone rubber seal. The balls float very high, providing a positive force on seal. Underway, the balls do get sucked off the seal if they are underwater. I would expect the same thing would happen with other flapper-style scuppers. Trim is critical here, to keep the scuppers out of the water.

5) I haven't seen these. Duckbills are used on marine toilets, and there are failures. The link says the flapper is made of thermoplastic rubber. That doesn't identify the type of rubber used which is critical in determining UV resistance. The rubber flappers you have have deteriorated likely at least in part from UV exposure. Silicone has good UV resistance.

Regarding sealant, the BoatUS link shows what I think is prudent. You don't really care if water leaks around the flange between the scupper and gel coat. What's critical is preventing water from getting into the plywood core in the transom. Com-Pac would do better by providing a proper thru-hull fitting in the transom rather than just trying to glass and seal the PVC drain in place. Renae had a significant problem with gaps around a drain pipe exiting the transom. Sealing the core from any water intrusion is important, including at any fastener screws.
https://cpyoa.com/forum/index.php?topic=11486.0

[Jim in TC]

I only read to "option 1" since that is the one I selected for the same issue in our Sun Cat. I figured that was the first and easiest thing to try and it worked! The seal is not perfect, but it has been adequate for the 4 or 5 years since I flipped them.

[Dave-in-RI]

Thanks, Jim. That might be what I try first, then. Does the Sun Cat have much of an issue with water coming in underway (if sitting in the far back corner, for example) or at a dock/anchor/mooring? Like Bruce, I had a Picnic Cat and if you even thought about having more weight in the back, water would come in (I would just plug the holes since it was a sunny day sailboat anyways). I haven't been able to take mine out yet to know firsthand.

[bruce]

Good to hear that the Sun Cat doesn't feature the self-filling cockpit!

I've drafted a press release:

"Always the innovator, in the Picnic Cat Com-Pac provides a novel self-filling feature, designed to replenish the cockpit live well and foot wash with locally-sourced, fresh and sparkling water. Farm to table for your summer dining!"

[Bob23]

Great write-up Bruce!

[Jim in TC]

I have experienced no issues with a "self-filling cockpit" while at rest, and she is in a slip all season long. Big rains drain well (some into the cabin...dripping from a source that continues to evade me). There are some conditions that allow some water into the cockpit while under way. Steep heel can bring water into the low side (I tend to heel a bit more than is optimal). With a heavy crew load it can become a bit more troublesome with potential for some damp shoes (we do not have a floor grate, which I think would alleviate that considerably). The only time it became a real issue was the overloaded boat, with 4 passengers who were not lightweights plus our regular crew of two (two were in the cabin to make room). This was probably well over 300 pounds in excess and we got quite a bit of water in the cockpit that evening...as I recall it 4 inches or so.

[MacGyver]

When I did the ones on my 19 I used the original style, which has the plastic white rings and the rubber center flap. The rubber went between the rings with lets say 75 to 80 percent cut leaving a small top part that held the flap. that being said, I use a rubebr conditioner to help keep that rubber soft, and that seemed to help for a while. Overall they should dump all the time but sometimes I think it is the nature of the beast to age and kind of warp outward or inward dependent on the lay of the rubber itself.

Mac

[bruce]

Jim,

We've all seen boats that take on water while at rest, and, in the absence a working bilge pump, sink. Clearly scuppers should never be relied upon to keep water out when the boat is unattended.

I see the Sun Cat has SS drain covers in the forward corners of the cockpit. Nicely finished, though not as easily plugged if you are taking in water heeled over with extra crew. I'm glad it's usually not a problem. Tom Ray talks about the PVC drain tubes glassed to the transom as the source of a leak to the bilges in one case. Fiberglass does not bond to PVC well.
https://www.tropicalboating.com/2015/09/sun-cat-wily-conch-for-sale

[Dave-in-RI]

I was just taking the dog out and peeked inside & up the scuppers. They dont go where I thought they did; need to map out.

[Jim in TC]

Jim,

We've all seen boats that take on water while at rest, and, in the absence a working bilge pump, sink. Clearly scuppers should never be relied upon to keep water out when the boat is unattended.

I see the Sun Cat has SS drain covers in the forward corners of the cockpit. Nicely finished, though not as easily plugged if you are taking in water heeled over with extra crew. I'm glad it's usually not a problem. Tom Ray talks about the PVC drain tubes glassed to the transom as the source of a leak to the bilges in one case. Fiberglass does not bond to PVC well.
https://www.tropicalboating.com/2015/09/sun-cat-wily-conch-for-sale

The scuppers on the Sun are above water, when at rest (something I wondered/worried about and checked before purchase). I agree that these flaps would not be up to the task if that were not the case (or at least, not to be relied upon).

[Ken J]

Anybody concerned about the pvc tubes that go from the scuppers to the floor drains - I?m concerned about storing much in those lockers for fear of those tubes breaking and possibly sinking the boat :-(

[Dave-in-RI]

I am, Ken! Like I wrote, I've only had it a couple weeks, and on land the whole time, but they're so long and flimsy and right there in the way of cramming soft coolers, backpacks, extra PFDs etc down there (like I could on my Picnic Cat). I wonder if there's a way to create a divider/wall/false floor (angled).

[bruce]

Dave, I know you've spent some quality time reviewing the archives. The topic of drain piping has come up, I don't recall any posts focused on the issue of cockpit piping vulnerability to damage. The use of glassed PVC pipe rather than real thru-hull fittings is often mentioned, as is the lack of access.

I'm sure there's a way to improve things, but not sure of the best approach. Boxing things in would work, but you'll lose some storage...too much?

[Jim in TC]

I have never exactly crammed stuff into those lockers but cushions, a bag of life jackets + a couple loose ones, and fenders go into the starboard side without incident (and that stuff gets messed with every time out). Next time aboard I will look to see just how close I am to the piping. And see if I can find a simple way to make it less vulnerable if it looks problematic. Since we primarily take water in via the scuppers on steep heels (with a bit of a load) or when just plain overloaded there is a fair chance you wont sink the boat with a compromised pipe, especially if you noticed it in time to pump it out with the bilge pump. When I was younger "fair chance" somehow seemed less scary...

Like Bruce, though, I do not recall any mention of problems with the piping in this or in the Trailer Sailor forum.