Minimizing thru-hulls

[bcooke]

I am looking for some good ideas or suggestions.

I have a growing list of thru-hull exits I need to locate on my Triton.

1.5" manual bilge pump
1.5" electric bilge pump
0.5" electric bilge pump
1.5" engine exhaust
0.75" deck drains (x2)

possibly a remote galley sink drain.

My first thought is to install these thru-hulls on the counter but it is starting to get a bit crowded there.

My original setup just had the manual bilge pump exiting out just to the side of the middle of the transom. I didn't like the look but now I am wondering about leaving it there and hoping the windvane mount hides the big mushroom fitting. I might even balance the look with another 1.5" hole a few inches away for the larger electric bilge pump.

I was thinking of installing the deck drains on the outer edges of the counter mostly as a way to better route the drain hoses and eliminate the connection with the cockpit drain tubes. I could also add drains on the outer aft edge of the poop deck and tee them into the regular Triton deck drain. Maybe I should rethink this.

I seem to remember Dasein with one of those 'christmas tree' multiple hose ports. How is that working out? (I could get two bilge pumps and the galley sink out through that one)

I also would like to install seacocks or ball valves on the drains (except the deck drains which remain completely above the waterline and isolated from the bilge or other low spots that could start a siphon) so the fewer thru-hulls the better it will be for my wallet.

On an aside...

I want to finish the insulation project I started a year ago but to do that I need to sort out the saloon settee backs and storage.
To sort out the settee backs I need to sort out the galley setup
To sort out the galley setup I need to install the fuel tank and battery boxes
To sort out the fuel tank I need to grind, paint and prep the areas under the cockpit
To finish the under cockpit area I need to figure out how I am going to install my thru-hulls...

Damn! That it is all connected!!

-Britton

[Duncan]

I think you're on the right track by combining - I have a separate through-hull to drain the icebox, for goodness sake!

On the other hand, I would think there's some value to having two different ways for bilge water to leave the boat (in case one gets clogged). Putting an electric and a manual on one, and the other electric and the engine on another seems sensible to me.

I'm not sure I really understand the value of the deck drains, but I'd be pretty reluctant to make another hole in the hull just to drain water off the deck?

[bcooke]

I'm not sure I really understand the value of the deck drains

They eliminate the dirt streaks where the water flows off the deck and down the sides of the hull. They also reduce the puddles at the low points of the deck. It is a minor cosmetic/annoyance thing. The deck drains could also be used to collect rain water and divert it to the freshwater tanks. I have mixed feelings about this. Tritons normally direct their deck water into the cockpit drains but I already re-engineered those drains and I don't want to tee into them anymore. I could dump the water into the cockpit but I am looking for alternatives.

I am not sure about connecting the engine exhaust with a bilge outlet but then again why not? As long as the Y-connection left no way for the bilge water to get diverted back into the exhaust system it should be okay.

-Britton

P.S. A dedicated icebox thru-hull? What a luxury! :-)

[Figment]

Deck drains: My memory fails on the specifics, but somewhere on this forum is a pic of a deck drain solid-molded down the side of the hull to exit just above the resting waterline. It's probably a hugely time-consuming alternative to a hose and fitting, but I dig the idea.

[Tim]

Direct your deck drains into the cockpit. It's simple and it works, and you don't have anything running down your hull. It'd also be straightforward to plumb in a valve for diverting the flow into jugs or tanks if you want to collect rainwater.

I don't think you should combine anything with the engine exhaust. I don't know offhand if there's an applicable standard regarding this or not, but that doesn't even matter: it just sounds like a suspect idea to ever introduce another water flow into a system where we take pains to prevent any water backflow.

For your multiple bilge pump outlets, I don't see why you couldn't come up with a custom-built (by you) manifold incorporating several hose nipples, all leading eventually to a single through hull. I imagine one could make something up out of stock bronze pipe parts, or possibly Marelon depending on parts availability.

Another option might be to build a sort of "reverse" sea chest in your lazarette--a fiberglass box permanently installed to the hull over a single through hull exiting the counter, and then install numerous inlets into the box for the various hoses.

[dasein668]

For your multiple bilge pump outlets, I don't see why you couldn't come up with a custom-built (by you) manifold incorporating several hose nipples, all leading eventually to a single through hull. I imagine one could make something up out of stock bronze pipe parts, or possibly Marelon depending on parts availability.

Unless I'm misunderstanding what's being said here, this is what I needed for my outlets (grey water sump, electric, and manual bilge pumps.). I used a stock plastic fitting:



It's this nylon fitting from Marine East. There are several types including barb ends, npt ends, and various combinations of hose sizes.

[Duncan]

I stand corrected on the idea of adding another connection to the engine exhaust, I hadn't thought that through.

I do think it might be good seamanship (i.e. built-in redundancy) to have two ways for bilge water to exit, though (i.e. not to run all bilge pumps to one manifold). Murphy's Law, basically: if the manifold ever gets blocked for any reason, you'd have all your eggs in the wrong basket?

Probably "academic", and I guess there's a trade-off against the "extra through-hull" failing, but there's a balance in everything, right? (When I was a banker, we always had to have "three ways out". I can remember a few times when the first two didn't work, and we were very happy to have the third.)

p.s. One of my back-ups is a handheld manual one with a long (15'-20') discharge hose I put on it. I realized that there's no point in having a six-foot hose when you're trying to pump the bilge, since none of the water goes overboard.

[Tim]

For your multiple bilge pump outlets, I don't see why you couldn't come up with a custom-built (by you) manifold incorporating several hose nipples, all leading eventually to a single through hull. I imagine one could make something up out of stock bronze pipe parts, or possibly Marelon depending on parts availability.

Unless I'm misunderstanding what's being said here, this is what I needed for my outlets (grey water sump, electric, and manual bilge pumps.). I used a stock plastic fitting:

I also used stock plastic fittings--a Rube Goldberg setup of which I am not proud, and which I would like to change. That said, it suffices for now and was borne of imminent necessity and the annoyingly incompatible sizes of various bilge pump fittings. I would stop very, very short of recommending anything like this, but there you have it. Take the good with the bad.

My point in suggesting the "custom" manifold was that it could be built of more durable materials, such as bronze or Marelon, if one chose to upgrade from the junky plastic fittings--as I suspect Britton might.

I really have to redo this now. This is purely embarrassing to look at.

[Tim]

I do think it might be good seamanship (i.e. built-in redundancy) to have two ways for bilge water to exit, though (i.e. not to run all bilge pumps to one manifold). Murphy's Law, basically: if the manifold ever gets blocked for any reason, you'd have all your eggs in the wrong basket?

Probably "academic", and I guess there's a trade-off against the "extra through-hull" failing, but there's a balance in everything, right?

I agree, and think that the manual pump--which is typically used for situations only when the electric pump fails--ought to have a separate discharge.

All the other pumps, sump drains, etc. could be combined into one through hull through one of the means discussed here, however, leaving the manual to serve as the backup for all events--whether it be pump failure, discharge clogging, or what have you.

[catamount]

If you're going to run multiple bilge pumps to a single outlet, that outlet should be sufficiently large so as to accommodate the discharge of all of the pumps connected to it all running simultaneously at their full capacity.
And generally, bilge pump discharges should not be connected to cockpit drains. (ISAF Offshore Special Regulations 3.23)

[Quetzalsailor]

I'm a little surprised at the lack of seacocks in the two pictures. Are these things above the water?

Certainly ganging uses is appropriate, once you've thought them through. For instance, our head sink and toilet water supply are piped to the same seacock. I'm not sure I'll leave them that way since you can hear the pump sucking from the drain. I've read about ganging multiple intakes through the same seacock and strainer; carefully thought through for capacity.

Deck drains piped to near or below the water are very nice for keeping things clean. Our North East 38 has 'em made like hat channels glassed to the hull and exiting below the water, the slight disadvantage being that they need bottom paint inside to discourage plugging. Another, slight disadvantage on Hinckleys, etc. that are piped, besides the complexity, is the noise they make, gurgling and sucking as the boat charges along.

I chose to bolt my seacocks to backup plates with the nuts captured between the plate and the hull, and the plates are epoxied to the hull. I can unbolt the seacock and unthread it from the throughull. Tapping the backup plate would work fine and doing the drilling and tapping before installing eliminates the bottom tapping. Put a dab of tape over the bottom of the hole when you glue the plate in.

I chose to not drill extra holes to throughbolt the seacocks. Even if glassed over, I fear thermal movement between 'glass and bronze and resultant cracking. I observed this on the strut bolts, and hull-deck bolts in our Morgan 27 (bolts were filled and gel-coated around the transom and past the ends of the toerails; very neat but only lasted about 20 years).

[dasein668]

I'm a little surprised at the lack of seacocks in the two pictures. Are these things above the water?

Yup.

[dasein668]

I also used stock plastic fittings--a Rube Goldberg setup of which I am not proud, and which I would like to change. That said, it suffices for now and was borne of imminent necessity and the annoyingly incompatible sizes of various bilge pump fittings. I would stop very, very short of recommending anything like this, but there you have it. Take the good with the bad.

My point in suggesting the "custom" manifold was that it could be built of more durable materials, such as bronze or Marelon, if one chose to upgrade from the junky plastic fittings--as I suspect Britton might.

Yikes! At least I was able to find a single fitting that worked for the 1 1/2, 1 1/8, and 3/4 inch hoses that I needed to mate to the 1 1/2 inch throughhull. But as you say, nylon certainly leaves something to be desired in the long run! And I definitely wouldn't go this route below the water line!

[Tim]

I'm a little surprised at the lack of seacocks in the two pictures. Are these things above the water?

Yup.

Ditto. And, as I said, not a proud moment in construction...yet illustrative in its badness despite its effectiveness.

[Figment]

This idea has some appeal.

Another option might be to build a sort of "reverse" sea chest in your lazarette--a fiberglass box permanently installed to the hull over a single through hull exiting the counter, and then install numerous inlets into the box for the various hoses.

What? Is my project list not long and unacheivable enough for you? Huh?!

[Rachel]

I think it was a Pearson Commander that had the drain fiberglassed up against the hull. Perhaps posted by Commander Pete.

[Jfwtc]

The Pearson Vanguard also has deck drains glassed to the sides of the hull

[Ric in Richmond]

Pearson Alberg 35 too.

[bcooke]

I really can't picture deck drains glassed to the hull. Hopefully someone has a photo around here...

Running the deck drains to the cockpit is probably my best bet but I am not 100% sold on the idea. There is a 2% part that keeps me wondering if there is a better way.

Now a reverse sea chest is certainly not something I would have thought of. Forums like this are great for expanding ones ideas. I am not sure about connecting the larger 1.5" hoses to a box because I don't want to introduce excess resistance in the high flow 'high priority' lines. Hopefully, I will never use the larger 2000 gph pump or the manual pump but if I did, I would want it to work as well as possible. I have plenty of pumping loss because I am lifting the water so high to begin with. I don't need to reduce the flow even further because of a bottleneck at the outlet. Some careful engineering would probably work here though.

Upon further thought, I think the engine exhaust should remain alone. I realized there is a small chance of exhaust gasses flowing both ways at a junction and pumping CO into my bilge via the bilge pump lines is not something I want to play around with.

Thanks people.

-Britton

[MikeD]

I really can't picture deck drains glassed to the hull. Hopefully someone has a photo around here...

Deck...


Hull...


Inside top...


Inside bottom...


You can thank my surveyor for the pics... :)

Album link...

[bcooke]

Thanks.

[Figment]

Oh, and why is it that bilge pumps discharge in 3/4" and 1-1/8" hose sizes? Why not 1"?

[catamount]

I have a Whale Gusher 8 manual bilge pump that uses 1" hoses...

[Tim]

Oh, and why is it that bilge pumps discharge in 3/4" and 1-1/8" hose sizes? Why not 1"?

3/4" I can stand, since it's a commonly available size for fittings of all types.

1-1/8" seems to be used ONLY for bilge pumps, and therefore requires use of cheap-o plastic bilge pump-y fittings and hose, or else applications of more Goldberg-type hose reducers/enlargers and connectors in order to make the oddball stuff coordinate with real fittings.

I'm going to try and avoid anything with a 1-1/8" fitting in my next boat. Sorry, Rule.

[bcooke]

I never got back to check this thread.

Oh, and why is it that bilge pumps discharge in 3/4" and 1-1/8" hose sizes? Why not 1"?

Huh... When I stuck my 2000gph Rule pump in the bilge I could swear I connected it to a 1.5" hose. Guess I better check that.

I stuck a 90 degree reducing elbow onto my little 200 gph Rule pump so it discharges through a 0.5" hose. The idea being a smaller hose will have less backflow when the pump shuts off. I think I will add a checkvalve in there too and see how long it lasts.

So, my plan now is to run the engine exhaust all by itself through one of those bronze flange thru-hulls that I see on Glissando and Dasein. (and sold only by Hamilton Marine I believe.) The manual pump and the small electric bilge pump will be connected via a homemade PVC fitting (still in the engineering department) to a normal mushroom thru-hull and the larger electric pump on its own mushroom thru-hull.

If I lose electricity I still have the manual pump. If I lose my custom fitting I still have the larger electric bilge pump (plus, if I go ahead and hook the toilet pump into the system like I am thinking...)

And yes, you have all convinced me. I will run the deck drains into the cockpit. If I get caught in a torrential rainstorm and my feet get wet from the deck draining into the cockpit then I will blame all of you equally.

3 thru-hulls. I can live with that.

-Britton

[bcooke]

Oh wait a minute... I think I got one of those bigger Rule pumps 3400 or something with the 1.5" outlets.

I knew I couldn't have been that silly :-)

-Britton

[bcooke]

Do those nice bronze flanged thru-hulls come with threads for seacocks?...

[Tim]

Do those nice bronze flanged thru-hulls come with threads for seacocks?...

No, assuming you're talking about the bronze exhaust outlets like those on Dasein. They have a hose barb on the inside.

You'd be fine with an inline valve for your engine exhaust shutoff, though.

[Tim]

If I get caught in a torrential rainstorm and my feet get wet from the deck draining into the cockpit then I will blame all of you equally.

If you get caught in a torrential rainstorm and somehow your feet don't get wet, then I'd like to know your secret!

(Oh, and no fair putting your feet directly in the drainage stream from the deck drains and then blaming us!)

[Rachel]

While looking over the Groco website I noticed this "new" item:



Here is their text of "the concept":

"To reduce the number of above waterline hull openings in your boat we offer a simple way to plumb multiple 1/2" or 3/4" ID low pressure lines (sinks and showers for example) to a single above waterline overboard drain fitting. The exterior look is clean and attractive , while inside is a compact grouping of all connected hoses."

You can find it on their site here:

http://www.groco.net/images/fittings/fittings-dm-5.html

As an aside, I was speaking with a fellow in their tech department today, and he mentioned that the BV and BVS series seacocks, which currently have a round base, are now (or soon will be) made with a triangular base, like their lower-priced seacocks. He said that this was for two reasons: 1) To standardize their product line, and 2) Because they were tired of people complaining that they couldn't fit a socket on to tighten the fasteners of the base; now that will be possible.

[Ceasar Choppy]

Interesting info on the Grocos.
I also have to say that the round bases made it extra hard to thru-bolt the seacocks to the hull unless you did this BEFORE attaching the thru-hull. The diamater of the flange of the seacock was about the same as the diameter of the flange of the thru-hull. The triangular bases are wider.

I saw that picture of the manifold on their website last year when I put in my sink drain/AC cooling water/show sump TH. I just made one up using a bronze cross and some tail pieces.

[Tim]

As an aside, I was speaking with a fellow in their tech department today, and he mentioned that the BV and BVS series seacocks, which currently have a round base, are now (or soon will be) made with a triangular base, like their lower-priced seacocks. He said that this was for two reasons: 1) To standardize their product line, and 2) Because they were tired of people complaining that they couldn't fit a socket on to tighten the fasteners of the base; now that will be possible.

Gee, that's too bad. I really like the round bases, except for the "space-saving" size as mentioned above.

I also have to say that the round bases made it extra hard to thru-bolt the seacocks to the hull unless you did this BEFORE attaching the thru-hull. The diamater of the flange of the seacock was about the same as the diameter of the flange of the thru-hull. The triangular bases are wider.

This is completely true and a bit annoying, though it's still possible to install things all at once--but it's certainly harder than it needs to be. I wondered why the round flanges weren't just 1/2" larger in both directions. This was my only complaint with these seacocks.

This is how it ends up with a regular through hull.