Cockpit floor drains

[John Husky]

I’m building a Fenwick Williams 18’ Catboat and trying to think ahead about centerboard design, etc. The drawing shows lead pipes for drains, port and starboard. The paperwork mentions a leather flap outside the hull. I can’t quite picture this, but my questions are thus:

Can I ignore the flap all together and have an open pipe at each side, or will this allow water in as she heels?

Can I pitch the deck to the center and have the cockpit drain into the centerboard well instead? (The centerboard case projects into the cockpit)

Draining into the centerboard appeals to me as a way to avoid through-hull perforations. I thank you for any insights you might share. The lead drain pipe is visible as a dotted line in the photo below.

7BC2BBA3-2761-4C56-9D3C-4561B1652FEB.jpg

[Peerie Maa]

I can't see from the image that you have provided whether draining into the cockpit will work. Rather than going directly down and out, most drains are crossed so that the port drain drains to starboard. That normally prevents water coming in when heeled. The flaps are a non-return valve, I wonder whether you can find a non-return hull valve commercially available.

[Jim Ledger]

Lead pipe drains are rarely used today, although they were once common. Lead pipe itself might be a difficult thing to source these days. My old catboat Sea Rover had lead pipe cockpit drains, each about a foot long, straight down, no flap. The hole on the planking was flared and the pipe was hammered to match, then secured with bronze tacks around the perimeter. The pipe came flush with the cockpit deck and had a patch of lead flashing nailed to the deck and bent into the pipe. No doubt there was some long gone deck canvas folded into the mix somehow. All very cude, but worked for seventy years.

There are cockpit drains with a rubber ball inside that will cope with inflow, slow it down anyway until you change tacks. I never had a problem with inflow, catboats shouldn't be heeled to much anyway.

On my boat I'm going to go with the two Perko drains I found on Ebay, some exhaust hose and a couple of thru hulls. I'm going to remove the rubber balls, though.

Jim

[Jim Ledger]

More...

It's tempting to drain things into the CB trunk. It could work, but, how will you get the thru hull in if the case is already built? And once it's in, how will you get it out if you need to? I'd rather have underwater perforations out where I can get to them.

Jim

[stromborg]

The cockpit floor isn't above the waterline by much. Are these drains intended to let rain water out while at anchor/moored and plugged while sailing? I know catboats are sailed fairly flat but leaving these open looks like a good way to sail with very wet feet all the time.

[John Husky]

Thanks for the replies. The cockpit floor is only about 4-5” above the DWL. I don’t have the drawings in front of me. Jim, I haven’t built the centerboard case yet, but the trunk end posts are in. I thought of putting the drain in the case sides at floor level. I feel like Nick’s suggestion of crossing each drain to the opposite side is a good idea. Am I correct that a boat moving through the water will tend to draw water out of the tubes rather than draw it in (The Bernoulli Effect?). I will research Perko and non-return hull valves, I’m not familiar with them.

[John Husky]

I’m thinking of running the 2 drains, port and starboard as in the drawing, to drain into the centerboard case sides. I can add in-line check valves, or scupper flaps, or ball valves to prevent back flow. I’ll have easy access to these fittings through hatches. Any feedback on this idea would be appreciated, I have never used any of the valves I mention, but they seem readily available through the usual retailers.

[Jim Ledger]

I think you see crossed drains more in deeper keel boats. It would be difficult to get a good pipe run in a catboat with shallow deadrise.

You want to keep in mind being able to clean out the pipe, all sorts of matter gets in those floor drains. That drain in the plan is very easy to clean by poking a stick down, it's a short, straight run.

Even if some seawater found it's way into the cockpit it's not like your feet would be in it, they'll be in the center of the deck, while the water would be under the seat getting your lunch wet instead.

Jim

[John Meachen]

A for and aft slope to the cockpit sole can help.You might then be able to use a through transom exit above a heeled waterline-if you can establish the heeled waterline.At the very least a sloping cockpit sole would ease your mind if the boat was left on a mooring for a few weeks without the inconvenience of a cover,but at the expense of the varnish suffering a bit of sunshine exposure.

[Oldad]

Mine were crossed there fore when heeled no water cam in. The large cockpit hatch gave access to the drain popes as well as the through hulls. It worked.

[Ian McColgin]

Marmalade (Brewer's Chappequiddic 25) is similar except that the through hull was moved inboard enough to install largish floating ball type check valves which had long since failed.

So when we heeled a bit water came back up the drain.

Since I could not repair or replace the check valves I tried the flap approach. Ineffective.

I'd done crossed hoses on deeper boats. Tried that but the hull is too shoal and the cockpit sole too close to the waterline to get workable geometry. You can by eye with a ruler against the plan see how hard it is to locate a through hull on the side opposite the drain that will come above the heeled waterline and not require water to run uphill from the the drain to the through hull.

So I considered how much water and figured that a small puddle around the leeward forward corner of the cockpit was really not a problem.

One thing I never liked about this sort of design is the impossibility of a seacock on the through hull. Before reliable rubber hose, lead was used for the drain pipes because it won't crack under repeated prolonged vibration, won't rot or deteriorate. Safe enough.

G'luck

[John Husky]

Thanks all. I greatly appreciate the advice.

[John Husky]

More...

It's tempting to drain things into the CB trunk. It could work, but, how will you get the thru hull in if the case is already built? And once it's in, how will you get it out if you need to? I'd rather have underwater perforations out where I can get to them.

Jim

It took me a while, but now I understand what you mean about getting to the fitting in the centerboard slot. I think that I’ll stick with Mr. Williams’ plan. I’ll give the inline check valve a bucket test before using in the boat. Since the Centerboard option is out I’ve got many moons before I come up against this.

[Ben Fuller]

I had one of these Fen Williams cats with this type of drain. I had no check valves. As I recall I had some plugs that I could use when heeling. They were meant to deal with rain, and they were not 100% because of the flanged fitting in the top. Put in when the boat was built with modern plastic hose and you can't get to the lower end. I think rainwater that didn't get out eventually led to problems. And I think when the cockpit was rebuilt they were taken out. Modern way would be to use what wasn't around then, electric bilge pumps, or what I have now on my open cockpit boat a really good cockpit cover. If you haven't check with the Catboat Association and see what the Marshall 18's or other 18 footers do.

One of the difficulties with the boat is that it is hard to fit an inboard and indeed I didn't have one. I had a big low hatch in the middle of the cockpit ( not sure it is on the plan). The boat that I copied , BUXOM LASS OF SALEM, was built in the late 40's and had a flat two cylinder Kermath that fit the space beautifully. Since you can't get the light 4 hp two strokes any more ( I used to pull the engine when sailing) if the dollars are around I'd be tempted to go electric. I added another 50 ' or so of sail so I didn't have light air issues but I did have to put the first reef in at about 10 knots of wind. Old School. I think one of GOBLIN's subsequent owners put in a small diesel and turned the cockpit hatch into a small engine box/ table. My old boat is now in Narragansett Bay, and is in the Catboat Association with its original name. Owner is a nice guy and would be amenable to questions.

[johngsandusky]

You might just let rainwater drain into the bilge and pump it out. My Friendship and Pennant Sloop did for forty years.

[Ben Fuller]

You might just let rainwater drain into the bilge and pump it out. My Friendship and Pennant Sloop did for forty years.

I'm kind of puzzled that Fen Williams didn't do this with the catboat. As I recall the cabin bulkhead went down to the sole as well, also unusual.

[wizbang 13]

If you get a load of water in the cockpit and the boat is moving, those will hardly drain. The water pressure of the moving water going past the opening slows the drain to an almost stop. One must install venturis (wood wedges are the simplest) over the drain on the hull. That stuff works fine for rain or spray, I'm talking about a 50 gallon wave or knockdown.Don't ask me how I know this.
bruce

[Jim Ledger]

Here's what the Perko scuppers look like. They're made for 1 1/2" hose.

I got this one on Ebay. If you have time you can do a saved search using keywords and you will be notified when one turns up.

If you mount them directly on the deck there will be an eighth inch lip, however, they can be recessed flush if the deck is solid wood..

[John Husky]

Thanks again. I’ll take some time to think on this. In the meantime I’ve just googled “antique brass bilge pump” and should be busy scrolling for some days.

[Ben Fuller]

Here's what the Perko scuppers look like. They're made for 1 1/2" hose.

I got this one on Ebay. If you have time you can do a saved search using keywords and you will be notified when one turns up.

If you mount them directly on the deck there will be an eighth inch lip, however, they can be recessed flush if the deck is solid wood..

I recall I had these as my floor drains; I had no one way valves in the system and water would come in sailing when the cat was heeled enough. They were also installed without being flush which led to rainwater pooling.

[alkorn]

With a scupper like the Perko you could perhaps buy or make a solid disk with the same threads as the drain strainer. The strainer could go in when at the dock to get rid of rainwater and the solid disk could go in when sailing. Then, when sailing, you would bail the cockpit as needed.

[peb]

D@#n, I am well past doing cockpit drains and thru holes, I never thought about draining it into the CB trunk. That wlmight have worked out quite well on my boat (Ron Mhor). All thou