H40 1984-1990 waste tank replacement.

[waternwaves]

Looking to install poly waste tanks inside the old tank locations in an 85 h40. (Under the nav and under the Vberth)
Before I make the mess, remove the floor, cut into the vberth......

I thought somebody might have saved the dimension of the tanks they had made, maybe?

And, did anyone try it while the boat was in the water?? There is no overboard system for the tanks on the boat. pump out only. I don't see any advantage to putting a macerator/discharge pump in since those would need a low point drain. (doesnt look like there is a lot of room for those pumps below deck) And the discharge would still need to come back up to through the deck into a thruhull. messy again. I willl probably put in the charcoal filter vents, and all new hoses, but since this boat uses saltwater flush I am looking to minimize odors too. (have to find a good locations for venting. Anchor locker? aft port lazarette, propane locker?.... ) REad the book, getting ready to do this much requested upgrade........ the boat is a former canadien plumbed boat with 2 locked y valves direct to tanks

So I am leaning to a simple same location fill, with same location deck pumpout.

Thanks in advance

darren

 

[Steve Dion]

I would not put vents in any locker. If/when the tank fills, it will spill sewage into those lockers. If you have no need for overboard discharge, then there will not be a need for a macerator. If you want to pump overboard, I am sure that there is a way to plumb this.

Check out Ronco Plastics for tanks that they stock. If these do not work there are some mfg on the east coast that can make custom tanks that will match what you have.

 

[sailingdog]

Can't help with the measurements, but I'd point out that you can put a diverter valve in the deck fill pumpout line and run it to a macerator or manual diaphragm pump and then to a seacock and through-hull to give your boat the ability to dump the tank when out past the three mile limit.

If the boat has a direct discharge seacock for the head, I would recommend plumbing the head directly into the holding tank and then plumbing one side of a Y-diverter valve in the deck fill line to that seacock and you won't even need to drill holes in the bottom of the boat.

I would not add charcoal filters to the vent lines, as they restrict air flow and a good flow of air into the tank is what will eliminate the odors by promoting the good aerobic bacteria and reducing the stinky anaerobic ones. Keep the vent line as short as possible and make it as straight as possible. Going up to a 1" diameter hose is a good idea too. Would second not putting the vents into a locker of any sort. They should go overboard, preferably near the toe rail or so... put a clamshell hood over them if you're using the 1" hose and through-hulls.

Use trident 101/102 for the waste discharge lines and Trident 148 for the water intake lines.

Looking to install poly waste tanks inside the old tank locations in an 85 h40. (Under the nav and under the Vberth)
Before I make the mess, remove the floor, cut into the vberth......

I thought somebody might have saved the dimension of the tanks they had made, maybe?

And, did anyone try it while the boat was in the water?? There is no overboard system for the tanks on the boat. pump out only. I don't see any advantage to putting a macerator/discharge pump in since those would need a low point drain. (doesnt look like there is a lot of room for those pumps below deck) And the discharge would still need to come back up to through the deck into a thruhull. messy again. I willl probably put in the charcoal filter vents, and all new hoses, but since this boat uses saltwater flush I am looking to minimize odors too. (have to find a good locations for venting. Anchor locker? aft port lazarette, propane locker?.... ) REad the book, getting ready to do this much requested upgrade........ the boat is a former canadien plumbed boat with 2 locked y valves direct to tanks

So I am leaning to a simple same location fill, with same location deck pumpout.

Thanks in advance

darren

 

[Peggie Hall HeadMistress]

Looking to install poly waste tanks inside the old tank locations in an 85 h40. (Under the nav and under the Vberth)
Before I make the mess, remove the floor, cut into the vberth......I thought somebody might have saved the dimension of the tanks they had made, maybe?

Ronco Plastics Ronco Plastics is your best source for tanks. They make top quality thick walled seamless rotomolded tanks for a very reasonable price (which becomes even more reasonable if you order it through the online store here sbo.com plumbing ) and have more than 400 shapes and sizes, over 100 of which are non rectangular. And they install fittings in the sizes and locations specified by the customer when they make the tank.

And, did anyone try it while the boat was in the water??

Unless you're installing a new thru-hull and seacock, there's no reason why a holding tank can't be installed in the water.

There is no overboard system for the tanks on the boat. pump out only. I don't see any advantage to putting a macerator/discharge pump in since those would need a low point drain. (doesnt look like there is a lot of room for those pumps below deck) And the discharge would still need to come back up to through the deck into a thruhull. messy again.

Not really...but unless you spend most of your time in open sea beyond the 3 mile limit, you don't really need a means of dumping the tank.

I willl probably put in the charcoal filter vents,

Very bad idea! 'Cuz vent line filters impede the flow of oxygen in and out of the tank, actually helping to cause the very problem they're sold to solve. And an even worse idea on a sailboat, because they only last a year at best, but are toast immediately if they get wet--which can happen when the boat heels if the tank vent fitting is in the wrong place, which it often is--and cost upwards of $50 each!

and all new hoses,

Trident 101 or 102 Trident Marine: Sanitation Hose is the most odor resistant hose on the market today.

but since this boat uses saltwater flush I am looking to minimize odors too.

If you search the archives--or if the book you claim to have read is mine--you'll find a simple method for eliminating sea water intake odors. However, as far the holding tank is concerned, whether you flush with sea water or fresh makes no difference at all.

(have to find a good locations for venting. Anchor locker? aft port lazarette, propane locker?.... )

None of the above. Because methane flammable, CG regs require that all waste tanks MUST be vented to the outside of the boat. So you cannot vent one into any locker or lazarette...nor can you use an unvented bladder to hold sewage or gray water.

REad the book...

What book? If mine, you must have missed the chapter "Holding Tank Odor--Odor Out the Vent" which explains exactly how to install and maintain an odor-free tank.

So I am leaning to a simple same location fill, with same location deck pumpout.

V-berth is a great location...but I wouldn't put a waste tank under the cabin sole...almost impossible to ventilate to keep it aerobic when it's buried too deep in the boat.

In your waters, I would seriously consider installing a Type I treatment device on the aft head instead of a holding tank...'cuz the discharge of treated waste from a CG certified device is legal in all WA waters...in fact on the whole west coast north of Santa CA...and the discharge is cleaner than that from sewage treatment plants. Check out the Raritan ElectroScan or the PuraSan here: Raritan Waste Treatment

 

[waternwaves]

1/2 our cruising is extended and 3 miles out.
I agree respirating the tank is best.
Obviously I shortened my message a bit too much.... I only use 1" vents, I dont use a separate strainer on the saltwater inlet,
As far as venting, my propane locker has a 3" vent combo fittingflash arrestor, and the locker has lots of circulation, I would go straight to the hull fitting and decrease the propane tank vent back down to 1" connection size.....my preference tho is to not route the vent past the head. my primary reason to avoid that is too much hose.
As far as tank connections, I always go to centerline of tanks for least slop during heel,
I have put in lectrasan in my 26, (made the mistake of using the previous unused 28 gallon waste storage tank tho... way to much garbage to hold,) and am very happy and familiar with MY electric head and system, My problem now tho is the marina I keep the boat at is a ndz obviously, and that treat, store, hold, move, pumpout later requires significantly more equipment space in 2 locations that were not really designed for that much equipment. 10 minutes of periodic pumpout during fueling is less time than it takes me to remove the fasteners and access covers inside cabinets to get to the lectrasan equipment. Don't get me wrong, I love the lectra san, so does the admiral, but it is a signficantly more complex system, with more to go wrong. (Dont have marginal batteries)

The reason I asked about doing the job in the water is a relative risk thing, using a recip saw in a boat is not fun, and breaking, bumping, flexing and general mechanical stress on thruhulls, even those that are less than 5 years old, has never been something I enjoy doing.
AS far as aeration v. activated charcoal/carbon scrubbing of vent gas.....aeration is dilution and source reduction, not capture. I have to disagree with you, a properly designed charcoal systems is effective. I use a 2 lb filter on the little boat, 3 ft. above the tank, it does not get wet. and lasts at least 6 months.....and does not appreciably affect the tank life respiration. I agree most holding tanks would be improved with a nicro type solar fan pumping air in all day. aerobic digeestion would be my preference, I am not going to put a liquids bubbler in each tank, (for obvious reasons, works great in septic tanks, difficult in moving holding tanks) Each tank will be speced for qty=2 1" ventlines, qty=1 1-1/2" pumpout, 4" threaded cleanout/cap. If I go with the purge fan, specs on the purge fan are 40 x 40 x 10 mm, DC12V, 0.07A, (on the supply, side dc permmagnet) .
I need to find/make a timer to cycle this minifan on and off.
As an engineer.....I need to have some way to empty the tank....not just clean it out. I have not found a small double diaphragm sludge pump I want to carry yet. As far as tank level monitoring, I will either shoot through the top of the or leave a port in the fiberglass floor.
I have seen a copy of your book, but my guidelines are for my work.
Design of Municipal Wastewater Treatment Plants (MOP 8; 5th Edition)
Wastewater Treatment Plants: Planning, Design, and Operation

I use trident hoses on my lectrasan now. and have measured for the new tank configuration

As far as tanks under the cabin sole......I am stuck with those locations (and why I am looking for measurements before I rip it up. ) at least for the short term, hence the purge fans. I also like keeping tanks low in the boat.. Doesnt matter a lot when the boat weighs 10 ton tho...
I did search the archives looking for measurements on the H40 , but thanks for checking. I find most of the head articles useful.
Thanks you all for the helpful responses.

 

[Peggie Hall HeadMistress]

You said," AS far as aeration v. activated charcoal/carbon scrubbing of vent gas.....aeration is dilution and source reduction, not capture. I have to disagree with you, a properly designed charcoal systems is effective."

Yes, it's effective at TRAPPING noxioux gasses, but not at preventing them. By blocking a free exchange of air, filters actually help to create anaerobic gasses. However, preventing 'em is the goal in designing an onboard system, and is actually quite easy.

You said, "As far as venting, my propane locker has a 3" vent combo fittingflash arrestor, and the locker has lots of circulation, I would go straight to the hull fitting and decrease the propane tank vent back down to 1" connection size.....my preference tho is to not route the vent past the head. my primary reason to avoid that is too much hose."

I've read that a dozen times and still have no idea where you plan to vent the tank. But I DO know that unless your tank vent terminates in a thru-hull into the atmosphere outside the boat, you'll be in violation of CG regulations.

You said, "I have seen a copy of your book, but my guidelines are for my work.
Design of Municipal Wastewater Treatment Plants (MOP 8; 5th Edition)
Wastewater Treatment Plants: Planning, Design, and Operation"

Ok...when you find out that landside wastewater treatment and onboard sewage management aren't the same thing, come back to see us...I'll be glad to help you sort out what you need to fix to turn a vastly over-complicated system into a MUCH simpler one that actually works.

 

[waternwaves]

perhaps I am coming across wrong...... I am not trying to irritate anyone here...
IT is a bronze thruhull combo fitting with wire screens on each of the three ports connections to the inside. It meets coastguard regs.
The source of off gas is tank goodies...respirating the tank with oxygen (blown in with the fan) prevents the buildup of the more noxious byproducts of anaerobic digestion. So putting in air is source reduction. The charcoal does VOC emissions capture. introduction of air into the digestion mix is a common practice on shipboard, selfcomposting and shorebased sewage treatment systems. A system can/is designed to exchange/vent just as much air as with charcoal scrubbing. ... as far as effective.... There would not be a paint booth in LA basin if charcoal wasnt effective at scrubbing VOC's
Please read my words carefully, I never said that" landside wastewater treatment and onboard sewage management " are the same thing...." I dont know where your comment comes from, perhaps I offended you, I did not intend to in any way. But the underlying process of waste treatment does not change significantly, the suspension fluid does with saltwater to some degree....but the principles are similar, The organic life doing the digestion does include more families with saltwater feed.
And I havent had a problem with systems that are "vastly overcomplicated.." I use a simple lectrasan MSD on one of my boats already, quite successfully. But that is more complex than what I intend on doing on my h40
All I was looking for was the inhull tank dimensions for lining an old tank with a new one.
Not looking to offend anyone.....
I think I will stay clear of this forum, so as not to bother the other users.

 

[Stu Jackson]

Shucks...

water...

Sorry you feel that way, and I think perhaps you doth protest too much.

I, too, read this the same way Peggie did.

You wrote: "but my guidelines are for my work. Design of Municipal Wastewater Treatment Plants (MOP 8; 5th Edition) Wastewater Treatment Plants: Planning, Design, and Operation"

That sure sounds to me like THAT'S what you're gonna follow, regardless of, as Peggie says, what's different between those "guidelines" and boat "plumbing."

I have often been chastised for being too harsh on some contributors, primarily because I sometimes call 'em as I see 'em.

In this case, if you're gonna pick up your marbles and go home, I suggest you reconsider. After all, all we can do is read what you've written and respond to the issues.

"Book?" Well, Peggie wrote it. I understand YOUR experience(s), yet I have not ever found Peggie's advice off the mark.

And the basic concept, regardless of your experience and studying, is that ANYTHING that's inserted in the vent line simply HAS to reduce the free flow of air and the issues related to stored-in-a-holding-tank crap.

BTW, I'm a registered professional mechanical engineer. What I've learned, over the years, is that KISS sure makes a lot of sense. I perform design management for my clients and have to help them constantly deal with "engineers" who seem to complicate simple issues. I oughta know, I used to be one!

And back to your original question: If it was my boat, I'd take it apart and make my OWN measurements, rather than asking others, who may have slightly different dimensions. Sure, it may take longer, but at least you'll get it right and won't have to consider returning a new tank that won't fit, if indeed they'd even take it back.

For instance, I just spent an hour today taking pictures of my battery box and trying to figure out if I wanted to install three new 12V batteries, or switch to 6V batteries. Armed with my measurements from MY boat, I then researched batteries and found I could replace the three 12Vs with new 12Vs with greater ah per battery and match the 6V ah capacity and even exceed it. The extra cost of the "larger" 12Vs will be more than offset by avoiding the cost of the paralleling wiring that would be required with a new 6V system.

"All" of our C34 battery boxes are "the same." But I measured MINE, since it's the only one I got!

Come on back, please.