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.hopkins-carter.com/thmaflmoscva.html)
https://www.wholesalemarine.com/t-h-marine-scupper-repair-kit/ (https://www.wholesalemarine.com/t-h-marine-scupper-repair-kit/)
https://www.wholesalemarine.com/th-marine-flush-mount-scupper-adapter.html (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 (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 (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 (https://www.boatus.com/expert-advice/expert-advice-archive/2013/october/how-to-install-a-one-way-scupper-valve)
Thank you.
Dave
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
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.
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.
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!"
Great write-up Bruce!
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.
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
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
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.
Quote from: bruce on May 10, 2023, 08:49:55 PM
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).
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 :-(
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).
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?
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.
Like you I only keep a few soft things in there - this Suncat is my third - and best - Compac and they all have the same setup that I have wondered about - and have not sunk yet so I guess all is ok 😜😜
I've not thought about those scupper tubes on my SunDayCat.
Maybe I should; at least take another look.
Roland
Yeah, the critical thing is that the boat doesn't take on water at rest, i.e. the scuppers are above the waterline. If you do take on water underway, due to heeling, loading, or trim, as long as the there is net positive draining, it should be OK. Even if the drain tubes are compromised, as long as collecting water doesn't submerge the scuppers, at rest the water should still drain through the scuppers.
The other issue, of course, is making sure rainwater, or the odd encroachment by a wake or wave, drains adequately. Even on a trailer, if water builds up in the boat bad things can happen. Dave saw how this can happen rather innocently parked under a tree.
On the topic about Epoxy and PVC, I did use the combo to repair the rear outputs on my 19 back when I redid the whole boat, When I fixed them I used a product called GFLEX by West System, using it as a carrier, and mixed some glass chop fines into it, then glued that as a joint to the boat, absolutely no issues over the years which also included a few drives across a few states, no cracking or issues are evident.
GFLEX is a modified Epoxy Resin, meant to be flexible. When I was first a part of the product when I received it from West System, I told them I had some testing options to try it on, one test was a set of Rubber boots well past their useful life. That employee used those same boots repaired with the GFLEX for another year and a half keeping his new ones in the box. A year and a half LOL
Mac
Yeah, I've had good luck with G/flex when I needed a flexible bond, although never under much load. They also suggest you can use it with polyethylene and ABS, both very difficult to bond. I'd have to see that!
PVC glues so readily to the full range of readily-available PVC fittings, including flanges, threaded and barbed adaptors, and unions. Pipe can be readily bent with heat to conform to bulkheads for support and protection, or sections of flexible tubing could be introduced. I'd be tempted to work with those rather than relying on fiberglass and sealants as thru-hulls, as some have failed. PVC is strong and cheap, has excellent moisture and UV resistance, and is easy to work. There are plastic thru-hulls with built-in scupper valves if you didn't want to go bronze or SS.
And then there's the access...
Took the old scuppers off today and noticed they'd been sealed not just in the screw holes but behind the plastic flange, too. What might take the old sealant off without hurting the gelcoat? Also, I was surprised by the layout of the scuppers. The highest holes are the bilge pump (top right) and just under the tiller seat at the top of gas tank compartment. You'd need a foot of water at least inside to need that. There's also one in the bottom of the gas tank compartment which is at the centerline low. The lowest two, far left and right, are the cockpit drains. Those are below the bottom paint on my boat, so surely would be first to fill, but it wouldn't make it up the cockpit drains without a lot of force. I wonder if the upper gas tank compartment scupper is for routing fuel lines as I've read some people used it for; can't have much useful purpose unless you're just about to sink in a bad way.
Not knowing what the old sealant is doesn't help. There's no need for high bond strength here, so it might just be a weaker polyurethane like Sikaflex 291 (my choice below the waterline) or 3M 4200, or a polysilfide like Life Calk.
You got the flanges off OK, so that's a good start. I would try to scrape off any residual sealant with a hard plastic scraper, PVC would work, or the old credit card trick. I often use bamboo, something that won't scratch the gel coat. Whatever I was using I'd chisel and sharpen the edge on a sander, refreshing it frequently. You could carefully try a dull metal putty knife or chisel, just make sure the edges don't dig in.
I would typically add water (with a little detergent to cut the surface tension), or naphtha/mineral spirits, that would flow under any edges I loosened so I could see my progress. I have tried WD-40 on a silicone sealant with minor success. There are removers marketed for this, I haven't played with these much. DeBond sounds good.
https://www.practical-sailor.com/boat-maintenance/removing-3m-5200
Gentle heat will soften the sealant, clearly you have to be careful not to damage the surface you're trying to protect. Don't heat solvents or removers unless instructed.
I wouldn't use abrasives on any residual sealant beyond what you might be familiar with when polishing a gel coat. I might try grey or maybe maroon ScotchBrite pads with a remover (listed above) or general cleaner, then let things dry and see where you are. White boats are very forgiving.
And then, especially above the waterline, welcome to world of butyl tape!
As I understand it - if you are attaching new scuppers they come with a rubber flange - at least that?s what I did
I find the drain at the back of the fuel tank compartment (which, with an electric motor is not used for fuel) to be useful when cleaning out that compartment, which seems to collect dirt and debris while in storage and also during the boating season. I can simply flow some water through. The bottom scuppers on our Sun are also lower than the waterline on the sides, not painted on the transom since it is above the water there.
I finally found time to go to West Marine and pick-up some cheap flapper scuppers yesterday (1yr old and 3yr old = never time for dad)-- what a ripoff! They wanted $21 for a single flapper style scupper in the store brand. Since I needed 5, that would've been $125 for a dollar's worth of parts! The Compac supplied ones say SeaDog on the flapper, which you can buy new right now from Bass Pro Shops for $5 each-- $100 less total. I left annoyed, and just came on to buy some online. Out of curiosity, I ordered the plastic flapper kind rather than the rubber flapper that curls. Amusingly to myself in regards to the above, these were $12.99 each (plus $10.99 shipping... but hey, better than $21-- and I get the learning experience of trying the new material). I came close to ordering the duckbill style for the lower set of three holes, but would have no way to clean out the two from the drain pipes should "things" find their way down into the long PVC tube. The bottom gas tank compartment one I could do, but I'd have to measure-out if it'd hit the rudder head and even still, that one I know I'd want to flush out. So, I'm half-reluctantly going with the plastic flapper kind all around, and may wind up ordering one rubber "regular" kind from elsewhere just in case the flapper won't work up top when I run the fuel line out from under the tiller. Just sharing my thoughts here for posterity's sake...
Got These:
https://thmarinesupplies.com/products/flush-mount-scupper-valve-assembly
(https://thmarinesupplies.com/products/flush-mount-scupper-valve-assembly)
They do sell a kit where you keep the white outer rings and add their new flappers, but mine were all marked up and I figured just replace with what they think fits best. Kits were $19 for 2 sets of flappers (2 for one size, 2 for another-- it's not 4 of the same like it looks in the photo):
https://thmarinesupplies.com/products/scupper-flapper-repair-kit (https://thmarinesupplies.com/products/scupper-flapper-repair-kit)
Scupper replacements came last night. Unsure if they'll fit yet, but some initial observations and pics. I got white on white (which allegedly is still UV resistant, though the white/black tie-wraps come to mind... most white ones can't take the sun).
1) They do not come with screws for putting into the transom; save your originals (I did). The collar/flange/trim appears taller from memory (haven't held it up against the original), and has recessed screw heads, so I'm hoping the old screws give equal extension out the back as the old ones.
2) The "plastic" flapper feels suspiciously like rubber to me. It's not smooth like the outer ring, it's "grippy" and flexible. Here's to hoping it doesn't curl like they promise.
3) The OEM (SeaDog) rubber flappers had the black flapper fully secured all the way around by the collar/flange/trim screws. On these T-H Marine flappers, it is only secured with a "set screw" at the top. Not sure how much strain / wear & tear it'll encounter, but I would've liked to see more attachment points so A) I dont irrationally worry it'll fall out, and B) I had a gasket running around the collar/flange/trim. Assuming the old screws fit and are long enough for this, I'm now going to put some sealant beneath rather than just in the screw holes.
4) Also included a pic from the Sea Dog site, where you can see the full coverage / behind-the-screws flapper plus gasket. Maybe I can re-use the old gaskets with some new adhesive...
(note- This forum randomly makes some images auto-load HUUUGE.... not my fault!)
Well, they do not fit due to the holes Compac drilled being in a different orientation. I don't feel like drilling new holes; would rather just double up on flapper ones. See pic:
Sorry the holes don't line up, even the same manufacturer can change things.
If you really want to use the T-H scuppers, you could fabricate mounting rings out of 1/8" aluminum for example. One set of holes to mount to the boat through the existing holes (well bedded), a second set of holes tapped to receive machine screws spaced to conform with the T-H layout (bedding not critical). 1/4" StarBoard would work, I'd go to 1/4" because threading in plastic is not as strong. Aluminum is easy to machine, stainless would be a pain.
Don't place too much stock in the rubber vs. plastic question, neither has a precise definition chemically. Rubbers generally have some elasticity, the ability to recover its original shape after deformation, whereas plastics generally deform more permanently (beyond a certain point). But, there are compounds that bridge the gap. Santoprene is an example. Some rubbers and plastics are formulated to have good UV resistance, but not all do. T-H doesn't say what their flappers are.
Similarly, pigments in general aid in preventing damage from UV. You mention cable ties (Nylon 66), and black, with pigments, is more durable than clear in UV. But, there are white pigments that are very good at blocking UV as well. Titanium white is excellent for example. Zinc white, somewhat more transparent, is used in sunscreen formulations for its UV protection. StarBoard (HD polyethylene) is formulated in white and black colors (and others). The pigment helps in UV resistance, but they also include UV stabilizers in their formulation to make the product durable in the marine environment.
Easiest to stay with what you've got. If you don't like the replacement flappers Sea Dog sells, you could cut your own out of rubber sheet. EPDM comes to mind, available in white and is used for industrial roofing. Lots of choices, full range of hardness, some have fabric reinforcement. McMaster Carr is a good source.
I just undertook this same operation last weekend. I opted to reuse the original sea-dog flaps, and turned them BACK to logo facing out, which I presume the PO did the exact thing once before. I found the old sealant came off cleanly with a razor blade, and if you attack it at a shallow enough angle it will not damage the gelcoat. All scuppers were rebedded with 3M 4200 save for the upper port scupper as that one is just going to serve as the through-hull for my fuel line. I will probably use a spray bottle of armorall to treat the flaps occasionally for UV protection. Perhaps that might slow the curling a bit.