Cockpit Drainage and Thru-hull Questions

[jkenan]

I wondered about that too, and was surprised a secondary strainer wasn't added to keep the plate scrapings out of the heat exchanger. I could easily see how a stray cocktail lime or a clump of eggs could create some blockage http://www.ericsonyachts.org/infoexchange/images/smilies121605/nerd.gif. Also, the manifold he created looks to be made of PVC valves, but I could be wrong. Besides that, he's got some great ideas and execution. Certainly a site for ideas...

 

[Greg Ross]

PVC Valves

Quote-Also, the manifold he created looks to be made of PVC valves-Quote
There's also a product known as CPVC for chemical applications, not sure if its' properties are enhanced vs UV exposure.

 

[u079721]

If we're all talking about the same photo, then maybe I'm missing something, but he says: "This feeds the watermaker; the galley sink; and the engine raw water pump."

I took that to mean it feeds the sea water pump, not the drain. I used a short manifold to feed both my sea water pump and my wash down pump, but I figured it would be better not to include the engine intake as well.

 

[anzam1]

I hope you guys don't mind me jumping in here.

My name is Brian Cleverly and I'm the builder/modifier of the Fuji 32 mentioned in this thread. If I may, I'd like to answer a couple of points raised here.

Cockpit drains:

The idea of solid drains is not new. They were standard procedure on many NZ built boats when I worked there 30 (or so) years ago.

While I agree there are boats out there that I would never fit these drains to, it may interest you that I have fitted them to an E32. This was in 1999, the boat being Bettina, the owner (Clay Gwin) being a longtime friend of mine.

She finished second in class in the 2000 Singlehanded TransPac and I delivered her back to San Francisco.

The delivery was the usual bash. We were knocked down twice and "pooped" a number of times. One of the crew members has a tale of the trip at:

http://homepage.mac.com/agunther/.Public/hawaii00/bettina.html

The comment re stress is somewhat valid and a very specific method of attaching the tubes is used. The photos in my text show the tubes when they are initially set in place, they do not show the actual tabbing procedure.

In practice, very little water comes into the cockpit via the drains and what little there is appears only in very extreme conditions. Personally, I am prepared to accept that slight inconvenience in return for very fast drainage.

On the matter of the salt water manifold. Some of you have not read what was written. The manifold is a source of water SUPPLY, drainage is not mentioned. In fact the galley sink drains straight down through it's own 1 1/2" seacock.

Yes, the valves are PVC. They are heavy duty schedule 80, rated for sewerage, and are ball valves with the ball operating in a nylon seat. I wonder why some of you thought PVC was a bad choice ?

The assembly is solid mounted with rubber hose connecting it to the strainer basket (also solid mounted), and rubber hose from there to the seacock.

When the cabin furniture is completed the manifold will be totally hidden from any possible UV rays. As for not running the engine raw water through the same manifold... Why not ? The flow rate of the cooling water is not high. In fact you can run a watermaker at the same time as the engine is running and not get starvation for either item. A galley pump uses less than the watermaker.

I'd welcome any further discussion you might have on this thread.

 

[jkenan]

Brian -

Just got back into town after working on my boat for the last week (and with limited internet access). I'm catching up on posts tonight, and saw your reply. Glad you chimed in, and welcome to THE Ericson site! I'll respond with a more thorough post once I have time to settle back into the groove, but wanted to say Hi, and welcome! I've really enjoyed following your Fuji project.

 

[u079721]

I hope you guys don't mind me jumping in here.

My name is Brian Cleverly and I'm the builder/modifier of the Fuji 32 mentioned in this thread. If I may, I'd like to answer a couple of points raised here.

Cockpit drains:

The idea of solid drains is not new. They were standard procedure on many NZ built boats when I worked there 30 (or so) years ago.

While I agree there are boats out there that I would never fit these drains to, it may interest you that I have fitted them to an E32. This was in 1999, the boat being Bettina, the owner (Clay Gwin) being a longtime friend of mine.

She finished second in class in the 2000 Singlehanded TransPac and I delivered her back to San Francisco.

The delivery was the usual bash. We were knocked down twice and "pooped" a number of times. One of the crew members has a tale of the trip at:

http://homepage.mac.com/agunther/.Public/hawaii00/bettina.html

The comment re stress is somewhat valid and a very specific method of attaching the tubes is used. The photos in my text show the tubes when they are initially set in place, they do not show the actual tabbing procedure.

In practice, very little water comes into the cockpit via the drains and what little there is appears only in very extreme conditions. Personally, I am prepared to accept that slight inconvenience in return for very fast drainage.

On the matter of the salt water manifold. Some of you have not read what was written. The manifold is a source of water SUPPLY, drainage is not mentioned. In fact the galley sink drains straight down through it's own 1 1/2" seacock.

Yes, the valves are PVC. They are heavy duty schedule 80, rated for sewerage, and are ball valves with the ball operating in a nylon seat. I wonder why some of you thought PVC was a bad choice ?

The assembly is solid mounted with rubber hose connecting it to the strainer basket (also solid mounted), and rubber hose from there to the seacock.

When the cabin furniture is completed the manifold will be totally hidden from any possible UV rays. As for not running the engine raw water through the same manifold... Why not ? The flow rate of the cooling water is not high. In fact you can run a watermaker at the same time as the engine is running and not get starvation for either item. A galley pump uses less than the watermaker.

I'd welcome any further discussion you might have on this thread.

Thanks for your comments. As for your questions, your set up does sort of violate a couple of sacred cow "rules of thumbs" that all the experts espouse.

The first is that we hear over and over not to use PVC below the water line because it is not fiber reinforced as is Marleon (sp?) to withstand vibration. I have to admit that schedule 80 stuff is pretty darn thick and durable, and seems up to the task. But I can well imagine a surveyor commenting on it in a survey, which would then require the skipper to fix it to get insurance (even if it doesn't need it).

The other rule of thumb is to not ever combine the engine intake with any other intake, for fear of starving the engine of cooling water. I have always thought this one was silly, as the flow of water through my engine raw water pump is so low that one through hull could easily supply the needs of the engine and a wash down pump (for example). But right or wrong you have again offended the "experts", though in this case I doubt a surveyor would care.

Nice work though, and I do like the twin drain tubes.

 

[anzam1]

Thanks for your comments. As for your questions, your set up does sort of violate a couple of sacred cow "rules of thumbs" that all the experts espouse.

The first is that we hear over and over not to use PVC below the water line because it is not fiber reinforced as is Marleon (sp?) to withstand vibration.

What you are referring to is the use of PVC piping that is unsupported.

That whole manifold is securely fastened to that bulkhead.

I have to admit that schedule 80 stuff is pretty darn thick and durable, and seems up to the task. But I can well imagine a surveyor commenting on it in a survey, which would then require the skipper to fix it to get insurance (even if it doesn't need it).

Very early in my life as a refurbisher (see www.anzam.com) I learnt that for insurance, and resale value, purposes it was prudent to have projects inspected by a surveyor at multiple stages. There is nothing I do that a surveyor has a problem with.

I'm well aware of the dangers of substituting materials but I'm also aware that there are many "rules" that no longer apply with todays materials.

Some 30 odd years, and 40,000 ocean miles, have taught me what works and what doesn't. I never use anything, or do anything, that will compromise my safety.

The other rule of thumb is to not ever combine the engine intake with any other intake, for fear of starving the engine of cooling water. I have always thought this one was silly, as the flow of water through my engine raw water pump is so low that one through hull could easily supply the needs of the engine and a wash down pump (for example). But right or wrong you have again offended the "experts", though in this case I doubt a surveyor would care.

I don't know what "experts" you are referring to here, but this is a situation where a "general" rule can not apply. It depends entirely on the engine flow rate and the thru-hull size.

What about the "experts" who state you should keep thru-hulls to a minimum... If you can't run more than one item via one thru-hull fitting you either have to have many thru-hull fittings or not have as many items requiring water.

Nice work though, and I do like the twin drain tubes.

Thanks, I try.

Actually you only see 2 drains, there are in fact 4 of them. Once I get further along I intend filling the cockpit and timing the drainage action.

 

[gareth harris]

I hope you guys don't mind me jumping in here.

The comment re stress is somewhat valid and a very specific method of attaching the tubes is used. The photos in my text show the tubes when they are initially set in place, they do not show the actual tabbing procedure.

I was away for this discussion, but I think fixed tubes could work well in the aft cockpit of the E35. The problem of back flow might be mitigated considerably by putting the tubes in the aft corners of the well, where the hull beneath them points aft to a good degree, and then running more conventional hoses from the forward corners to a central through hull - three drainage holes in all, all above the resting water line.

My one real concern is the tabbing procedure. The yard my boat is at have told me they can do it, but being on the Erie Canal they do not deal with too many truly sea worthy boats. What should I be on the lookout for, and making sure gets done right?

Gareth
Freyja E35 #241 1972

 

[anzam1]

I was away for this discussion, but I think fixed tubes could work well in the aft cockpit of the E35.

In the E32 I did I fitted horizontal tubes between the fwd outer corners of the aft cockpit and the main cockpit. These handled the aft drainage very well.

The problem of back flow might be mitigated

Backflow really is no problem other than in extreme conditions.

three drainage holes in all, all above the resting water line.

Since this discussion started I've learnt that the ABYC Standards (2008-09 revision), section H-27 (Seacocks), now allows penetrations between the maximum heeled water line and the static float plane, and *DOES NOT* require a seacock, provided that reinforced piping, or hose that resists kinking and collapse, is employed.

Finally, the "experts" have seen the light.

My one real concern is the tabbing procedure. The yard my boat is at have told me they can do it, but being on the Erie Canal they do not deal with too many truly sea worthy boats. What should I be on the lookout for, and making sure gets done right?

Firstly, Epoxy MUST be used... I would never do this work relying on Polyester.

Secondly, the pipe/tube used must be of fiberglass and be at least 1/4" wall thickness. I make my own tubes, but you may be able to obtain them ready-made (of G8 probably).

The procedure is perhaps too lengthy to post here. I have been meaning to write it up, with progressive photos, and make it available on my website.

Are you in any hurry to have this mod done ? I could have my text done maybe by end of November at latest.

 

[anzam1]

Just as an addition to this thread (which I forgot to mention).

It is generally accepted that you should have 4 sq in of drain for every 1 cu ft of water to be drained in order to have it drain between waves.

 

[gareth harris]

Are you in any hurry to have this mod done ? I could have my text done maybe by end of November at latest.

I will not be doing this until the spring, so if you have it written by then it would be a great help to me.

Three 2" drain holes are about perfect for the aft well by the formula you quote, but the forward well would need 5 holes at that size. I am not yet sure how to work that, I will be mulling it over between now and the spring.

Gareth
Freyja E35 #241 1972

 

[anzam1]

I will not be doing this until the spring, so if you have it written by then it would be a great help to me.

I'll see what I can do.

Three 2" drain holes are about perfect for the aft well by the formula you quote, but the forward well would need 5 holes at that size. I am not yet sure how to work that, I will be mulling it over between now and the spring.

You have missed one piece of info in that quote of mine and that is "between waves".

For normal use (not being continually swept by waves) 2 x 2" in each pit should be ample.

I mentioned the E32 I did and I think I mentioned in an earlier posting that I delivered this boat back from Hawaii. On the way back we were "pooped" a few times and knocked down twice but just the 2 drains (total) handled all the water just fine.

The operative factor here is that they drained straight down... No bends/tees to contend with.

 

[gareth harris]

For normal use (not being continually swept by waves) 2 x 2" in each pit should be ample.

Any chance you could post a link here when you have written it up? (I have just found out it may be sooner than spring when I do it, but not until after Christmas). Thanks in advance.

My design specification is for a boat to handle the north Atlantic, which is where I plan on be going when she is done, so I need to expect to be caught out in a fairly nasty storm. On the other hand, I do not really want the aft hull to look like Swiss cheese.

That is some good experience you describe, as the E32 and E35 are fairly similar in that part of design. I think having the aft cockpit full of water would be a big problem in a large swell, as the cockpit is so wide that 700lbs of water could cause a very large moment to compound a roll; plus that much weight that far aft could also throw off the basic handling in waves.

Gareth
Freyja E35 #241 1972

 

[anzam1]

Any chance you could post a link here when you have written it up? (I have just found out it may be sooner than spring when I do it, but not until after Christmas). Thanks in advance.

That's what I intended doing.

My design specification is for a boat to handle the north Atlantic, which is where I plan on be going when she is done, so I need to expect to be caught out in a fairly nasty storm.

Coincidence, I'm doing the Fuji for extended cruising in the Nth Pacific and Bering Sea areas. I plan on doing some environmental research there.

That is some good experience you describe, as the E32 and E35 are fairly similar in that part of design. I think having the aft cockpit full of water would be a big problem in a large swell, as the cockpit is so wide that 700lbs of water could cause a very large moment to compound a roll; plus that much weight that far aft could also throw off the basic handling in waves.

As I mentioned, for the E32 I installed horizontal drains connecting the two pits. They were the same 2" that I fitted for the main drains, and cleared the aft pit very quickly.

 

[jkenan]

I kinda had a feeling Brian was a viking at heart....

Glad your here, and I am closely following this thread, and very appreciative of the knowledge you are sharing. I'm checking Anzam every few days to see if there are updates.

I'd appreciate your thoughts on the cockpit replumb I'm redoing on my E29. I won't be in blue water for any extended periods, but could experience some heavy conditions with squalls, etc. We have our 2nd child on the way (Dec 9th), and am pretty certain we'll be cruising the Palmico sound, ICW, and maybe the occaisional Cape Lookout trip from Beaufort over the next 5 or six years. After that, maybe (and a big maybe), an outside trip to Wilmington, Charleston, and Bahamas . But I do get away with the guys once in a while and we'll head out Beaufort inlet and around Cape Lookout for the Gulf Stream, and sail up to Ocracoke. We turn that leg of it into an overnighter.

So in general we'll likely be able to avoid the lasting heavy stuff, but my get caught in some rough stuff for a little while. The Palmico sound can be nasty too - I've sailed there in 30 knots with steep 8-foot breaking waves.

I want to move thru-hulls above the waterline, and widen to 2" openings. Thru-hulls above the waterline are important b/c the boat spends long stretches (especially in winter) unattended on a mooring and winterization can sometimes be a concern (the creek has frozen over before). All old thru-hull openings are patched with triax, and the peeled hull relaminated with triax. I want to go from 7 holes below the waterline to three - one of them being for speed. I'd keep the cockpit drains as 4x 1.5", with a Centek Y fitting (A & B being 1.5" and C being 2") connecting the fore and aft drains on either side, depositing to a 2" thru-hull above waterline. Since the thru-hull hardware stands up several inches (there is a 45 degree elbow from the flange so it points towards the drains instead of up), the hose run is pretty short. The 2" hose will only need to be about 10" from the thru-hull to the Y fitting, and the 1.5" aft drain hose only a couple of inches to the Y and the fore drain hose 16" to the Y. The run from the drains to the Y will be about a 10-degree slope, and from the Y to the thru-hull about 35-degrees.

I'll only be able to test it once it is done, and at that point won't be able to do much more to it. Do you think this is an adequate plan, or flawed? I have the hardware, but haven't installed yet. I would be receptive to laminating a 1.5" tube to connect drains, but don't know how (I've relaminated the whole boat with triax after peeling, and am building a holding tank much like the water tank you built, so I am no stranger to epoxy and glass).

Gareth's approach is for blue-water. Mine is for better drainage than I had, with peace of mind via fewer below waterline thru-hulls. I'm sure both approaches have merit based on the intended use, and think your insight would be very interesting to members here.

Thanks in in advance!

 

[anzam1]

I kinda had a feeling Brian was a viking at heart....

Was, was ???? I ain't dead yet, close, but not quite there

Glad your here, and I am closely following this thread, and very appreciative of the knowledge you are sharing. I'm checking Anzam every few days to see if there are updates.

Thanks for the kind words... Due to a number of issues I don't expect there will be any updates until the end of the year. I did however, pass a milestone this week in putting the engine to sleep in its comfortable bed.

I'd appreciate your thoughts on the cockpit replumb I'm redoing on my E29......

I don't have any experience in your waters but would comment that what Gareth and I are preparing for is the probablility of being pooped, and maybe successive times at that.

For your planned voyages I'd suggest that an improved OEM situation would be fine.

I want to move thru-hulls above the waterline, and widen to 2" openings. Thru-hulls above the waterline are important b/c the boat spends long stretches (especially in winter) unattended on a mooring and winterization can sometimes be a concern (the creek has frozen over before).

Fortunately I've never had to deal with that... But I can see your concerns.

All old thru-hull openings are patched with triax, and the peeled hull relaminated with triax.

You've been a busy bee

I want to go from 7 holes below the waterline to three - one of them being for speed. I'd keep the cockpit drains as 4x 1.5", with a Centek Y fitting (A & B being 1.5" and C being 2") connecting the fore and aft drains on either side, depositing to a 2" thru-hull above waterline. Since the thru-hull hardware stands up several inches (there is a 45 degree elbow from the flange so it points towards the drains instead of up), the hose run is pretty short.

OK, first consider you are connecting 3.53 sq in (2 x 1.766) to 3.14 sq in so the drainage will only be as quick as the 2" can handle... Then consider that both the "Y" and the Elbow will slow down water movement.

The 2" hose will only need to be about 10" from the thru-hull to the Y fitting, and the 1.5" aft drain hose only a couple of inches to the Y and the fore drain hose 16" to the Y. The run from the drains to the Y will be about a 10-degree slope, and from the Y to the thru-hull about 35-degrees.

That 10 deg worries me a bit... Could you not place the "Y" closer to the thru-hull and increas that angle somewhat?

I'll only be able to test it once it is done, and at that point won't be able to do much more to it.

If I were you I'd make up a test case... Attach 2 x 1 1/2" hoses to a 5 gallon container, attach those to the "Y" followed by a short piece of 2" and the elbow.

Fill the container and measure time to drain it. Test draining thru both hoses then one hose, I don't think you'll see much difference.

Also test with different angles on the smaller hoses.

Now test the current setup on the boat again using 5 gallons.

Now you have sufficient info to point you in the right direction.

I would be receptive to laminating a 1.5" tube to connect drains, but don't know how

I don't think that would give any advantage in this situation. Just make sure that whatever hose you use has a continuously **SMOOTH** interior.

Actually, making glass tubing is not difficult. Depending on the dia and length I want, I use either a cardboard tube or PVC pipe for the form.

The cardboard is easy because all you do is soak it overnight in water, but the PVC can be a slight problem because it is very difficult to find a piece that is perfectly straight. If it is not straight you can't slide the lamination off it once cured.

To prepare the cardboard all you need do is cover it with "CERAN" wrap (genuine product works best). With the PVC you need to coat it with a good Carnuaba Wax (2 coats), polish it well then spray with PVA mold release.

For glass you need 3" wide 12oz cloth tape and 17oz stitched (aka knitted) biaxial with mat tape. Sometimes called "X" cloth, "Knytex" is a well known brand.

You are going to apply the tape by spiral winding it with about a 1/4" overlap.

First layer is the cloth. If you are using PVC, let this layer cure and see if you can slide it off the form. If you can't, the form is not straight and you'll have to split the glass lengthwise to remove it (but that is not a worry as you will use that as the new form and you'll be closing the split as you apply the rest).

Now apply the rest, alternating cloth and Biaxial and alternating the direction of the spirals after each biaxial layer. Number of layers depends on what thickness you want, but I do a minimum of 3 each, wet on wet.

 

[jkenan]

Thanks for the feedback. Your test idea is a good one, and I'll give it a shot before committing to any installations. I'm not planning on using seacocks on the scupper drainage since the drains are above water line, not required by ABYC, and I'll be using hardwall hoses with the higher-quality stamped hose clamps, so I think I will be able to get the Y-fitting closer to the barb as you suggested.

Thanks again for the how-to on building a fiberglass tube. All very good information.

Good luck with the Fuji project, and I'll look forward to updates when you are able to get back to that project. I'm in a similar boat (really, no pun intended) - this coming weekend is my last opportunity to get anything done because after that I'll be sticking close to home waiting for #2 scheduled for December - and won't be able to get back on the E29 until February or so.

In the meantime, I'll be thinking about rigging two kid-sized hammocks in the Vee-berth and converting a settee into a double. Hmmmm....

 

[anzam1]

Hi John,

Best wishes for December.

Re the hammocks.... Don't forget a system of dampers, otherwise they'll quickly become uncontrolled pendulums.

 

[jkenan]

Good call on the hammocks. I'll think about that one.

One last thing - I would (and I'm sure everyone here would) enjoy hearing about the specific tabbing procedure for connecting the tube to the cockpit or hull. I don't have any immediate need for it, so if you don't get around to it, no worries.

Thanks for sharing your knowledge!

 

[anzam1]

John and all,

For those interested I've just posted an update to the Fuji project notes at:

www.anzam.com/images/fuji/project/work_begins/welcome.htm