Aroma

[what_barnacles]

at first glance the pvc doesnt look secure enough to take rough water. maybe a joint has broken the glues bond and when flexing it lets odor out.

 

[klee wyck]

Just a WAG theory to contribute based on the specific circumstances you describe: intermittent, appears to be associated with increased motion when boat under way only.
Boats underway with any windows, doors, sun roofs, vents open can create a draft of negative pressure in the boat interior. Some marine plumbing has shallow, almost horizontal traps in the system, especially at sinks in the head.
If you take the draft combined with the rocking and that empties the water out of the u-bend in the trap, you essentially have the holding tank vented to the interior of the boat. Next time you get a whiff, try adding some water to the traps and see if it goes away. I think even a healthy holding tank will have a little odor when you stir it up in big seas and if the trap becomes a vent this will get sucked up into the boat.

 

[HeadMistress]

Polyurethane tanks good, metal tanks bad,

I think you mean polyETHYLENE tanks, not polyurethane.

fiberglass I don't know. I would think a well made fiberglass tank would be good. Peggie, can a fiberglass tank get permeated and smell? Should he do a rag test on his tank?

I won't say it can't happen, but in 30+ years I've never heard of a FG tank permeating. As for all these arcane theories about all the ways a tank that's vented to the outside of the boat can vent inside the boat, I've yet to hear of any of that happening either. And fwiw, p-traps in sink drains serve a purpose on land, but on boats create more problems than they prevent or solve.

And while I have the floor...it wouldn't take nearly as long to post photos and they wouldn't be the size of a bed sheet if you do two things: 1. Before you try to upload them, reduce the IMAGE size (not the size of the picture, the size of the file) from the 3+ MB most originals are to a max of 600 dpi for the longest side (easy to do in any photo editing software...it's a very short learning curve)...and 2. Choose 'thumbnail' when you post 'em. I doubt if I'm the only one who'll appreciate it.

 

[C lectric]

Fiberglass tanks do work and well. Mine is made of that although I used epoxy, not polyester, as the resin. Walls are between 1/4" and 3/8" thick. Done now about 17 years ago and nary a whiff.
I did ask about my choice of material and was told it would make a good tank. Originally the idea was to use polyester with a layer of epoxy but I figured nuts and used epoxy.

 

[Spottsville]

Our Fiberglass tanks are structurally integrated into the hull and are 1/2 inch thick and made with vinylester and don't permeate.

Peggy is the expert...get her book!

 

[ktdtx]

We are stuck in Shearwater/Bella Bella for a couple days due to heavy winds.
Spent yesterday taking the bed apart to access the "hidden bilge" as best I could. Some "brown bilge water" there but no odor even when stirred.

Cleaned with Scrubbing bubbles and brush 2x and rinsed 3x and pumped out and dried the area. There is still an area of bilge I absolutely cannot access--there is a 200 gallon water tank under the bed which covers some of the bilge forward of where I accessed.

In the process of ordering the book.

 

[Spottsville]

Once you read Peggie's book you will start thinking about how to get more air in your holding tank. Spotted this and wondered if it works and how long it will pump before it wears out the air pump?

Groco SweetTank Holding Tank Odor Neutralization System.

http://www.defender.com/product.jsp?path=-1|51|2234284|2234295&id=1807419

 

[Comodave]

I had one in a previous boat. Worked GREAT. The pump lasted 8 years while I had it and was still going strong. No smell in the holding tank. No chemicals were added for 8+ years after I added the Sweettank.

 

[Spottsville]

Thanks Comodave, good to know. After reading Peggie's book I removed my carbon filter and am waiting to see if I need more air in the tank. I can get to the top of my fiberglass holding tank without too much trouble. It's under the master bed. I could mount it next to the Maretron tank level gauge. I also have 12V there. How loud was the pump?

 

[Comodave]

Ours was in the engine room. I first mounted it on top of the 80 gallon fiberglass holding tank. It seemed to have a slight drumming noise so I moved it to a bulkhead and put a soft pad between it and the bulkhead. You could not hear it unless it was dead quiet and you were in the ER.

 

[Spottsville]

Here is the Passagemaker article on a similar approach:

http://www.passagemaker.com/technical/foul-odors-run-deep

 

[Spottsville]

Was considering installing a second vent in the tank on the opposite side (starboard) as my present vent but also entails drilling the tank. The bubbler lets you know if it's not working (motor stops) which I like vs vent. With a switch to shut off at night if it's too loud, to me a great option.

 

[Comodave]

The article is absolutely right on except for using a stainless steel tube down into the tank. The s/s will rot in the urine. Groco uses a fiberglass rod. Minor point but if anyone is going to diy it, use a nonmetallic tube. Groco has a simple plug that goes into a 2" hole on top of the tank for the downrod to go through. It took only 45 minutes to install once I got enough courage up to pull the trigger on the drill and put a 2" hole in a tank of poop.

 

[HeadMistress]

All your comments are all well and good and I do appreciate the plugs for my book...but either you've changed the subject to eliminating odor out the vent or you logged into this thread too late to read my first reply to it which can be summarized: If your problem is odor INSIDE the boat, anything you do to the holding tank is just chasing your tail because the tank isn't the source.

 

[Spottsville]

Peggie I see what you mean and your right sorry for the sidetrack. For me, my oder problem to date has been the vent and your book and the better understanding of the different bacteria was very instructive.

 

[HeadMistress]

If you need a little one-on-one help to eliminating the odor out the vent, you're welcome give me a shout via private message.

 

[BerettaRacer]

OK, coming into this late but here's a different take on the issue. As Peggy says the odor is inside the boat it's a different issue. Here's two separate but similar problems I've had in the past under your "rough weather" conditions.

-During weather with boat bouncing around fouls smell was traced to seal water being knocked out of sink or shower traps allowing gray water odors into the boat, easy fix just run a quart of water down the drain to refill the traps, they are called traps for a reason, long term install deeper traps.

-Same issue, weather causing foul odor, problem was traced to the air conditioner condensate drain which had been led to gray water tank. During rough weather and gray tank agitation, the negative air pressure zone inside the a/c fan return area was sucking gray water fumes UP the 1/2" condensate drain line and the a/c fan was distributing the odor into the boat.

Just two similar odor problems I've had, may or may not be your issue. As they say YMMV.

ps: As has been stated above, a properly aerated black tank has literally no smell, but gray tanks stink, badly!

 

[HeadMistress]

Neither of those were on my radar, most likely because neither gray water tanks nor P-traps are common on boats <50', which is 99% of 'em (95% of registered boats in the US are <35'). However, I'll add your post my reference files 'cuz things I'd never heard of before have an uncanny way of popping up again.

As has been stated above, a properly aerated black tank has literally no smell, but gray tanks stink, badly!

Black water tanks are a "walk in the park" to maintain compared to gray water tanks because everything in a black water tank dissolves--at least everything that belongs in one does. But a lot of what goes down sink drains, especially galley sinks (food bits, etc), doesn't...compounded by cooking grease etc. Add the soap scum, body oils, bacteria etc in shower water and you have a unmanageable primordial soup! I've yet to come a cross any tank "treatment" that does much to help.

 

[ranger58sb]

-During weather with boat bouncing around fouls smell was traced to seal water being knocked out of sink or shower traps allowing gray water odors into the boat, easy fix just run a quart of water down the drain to refill the traps, they are called traps for a reason, long term install deeper traps.

Neither of those were on my radar, most likely because neither gray water tanks nor P-traps are common on boats <50', which is 99% of 'em (95% of registered boats in the US are <35').

But a lot of what goes down sink drains, especially galley sinks (food bits, etc), doesn't...compounded by cooking grease etc. Add the soap scum, body oils, bacteria etc in shower water and you have a unmanageable primordial soup! I've yet to come a cross any tank "treatment" that does much to help.

The P-trap in the drain hose in our head sink is particularly prone to this... The trap is so deep, it takes a serious bit of fresh water to flush.

FWIW, sometimes it helps to agitate the "lettuce" in there with a small plunger... before following with copious flushing.

Either CP, KO, or Noflex seems to help. CP seems to be about as good as any, and we sometimes put a small dose of that into the trap to let it sit for a bit, before working the plunger and flushing.

-Chris

 

[HeadMistress]

CP seems to be about as good as any, and we sometimes put a small dose of that into the trap to let it sit for a bit, before working the plunger and flushing.

I dunno know how long "a bit" is, but if it's less than 6-8 hours, it's not long enough to do much good. It's not a chemical product that works immediately...it's a bio-enzymatic product. The enzymes in it need enough time to "eat" the stuff that builds up in drains...not only galley, but sink and shower drains too. It does a great job of keeping sumps clean. Put at least 2-3 oz. of it down the drain, then fill the trap the rest of the way with water. And I wouldn't only use it just to "cure" a problem...once a week will prevent it. Last thing before you turn in at night is a good time to do this, or last thing before closing up the boat. C.P. can remain in the plumbing forever without doing any harm to anything...it just stops working after 24 hours.

Fwiw, C.P. is part of the product line Raritan bought from me in 1999. So I'm very familiar with it.

Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

 

[ranger58sb]

Yep, and that's what I meant for "a bit" -- often overnight.... or maybe all day while we're off doing something else...

Our galley sink trap isn't quite so huge, so we have less of a problem there.

And yep, we started using CP/KO way back in your CompuServe days... thought I'd give your stuff a plug while I was at it.

-Chris

 

[HeadMistress]

OMG that was 25 years ago! Those were the days, my friend...great memories.

 

[ranger58sb]

OMG that was 25 years ago! Those were the days, my friend...great memories.

BTW, Dave (Sea Q) mentioned in a PM that he was surprised Noflex didn't work to clean the P-trap in our head sink.

Told him I didn't mean to suggest it didn't work, I just wanted to give you a plug and have a laugh harking back to the pre-'Net days, when the stand-alone electronic playgrounds like CompuServe, The Source, Prodigy, etc... (and later, AOL)... began emerging and/or still existed...

But to address that thought (for other readers), Noflex seems to work as well. The main reason we use CP in that drain is because the mechanical plug in the sink isn't quickly/easily removable... so it's just slightly easier to squirt the right amount of liquid CP down the drain, compared to crystalline Noflex.

And we keep both CP and Noflex aboard...

-Chris

 

[dhays]

Fwiw, C.P. is part of the product line Raritan bought from me in 1999. So I'm very familiar with it.

I guess I never paid attention to that part of your bio.

We have been using the C.P. In the shower drain after all showers are done, but this thread has me thinking that using it in the sink drains when leaving the boat is a good idea as well.

 

[Spottsville]

Have a 56 foot Carver docked next to me and boy did his blackwater tank stink. I said something to him about the oder on the dock and he seemed dumbfounded. The next day he mentioned he put bleach down the toilet to kill the odor. And the oder did stop.... Now over a month later the oder is still gone. So, I would think the bleach killed the bacteria that was stinking, but got me to thinking once the bacteria was dead how long would it take for the smelly bacteria to return? Also once the smelly bacteria is dead what should he do to grow the good (not smelly) bacteria? Was his solution a good or bad idea?

 

[dhays]

You don't know what else he did. Maybe he also pumped his holding tank and started to use the boat more? In my (ignorant) mind, bleach is just a short-term solution. Long term there are some holding tank treatments that may work well. If he has adequate holding tank venting (not likely) then Raritan K.O. would work well. If he doesn't have adequate venting (more likely) then I would look to something like Odorlos or No-Ox. I am using both.

 

[gaston]

Have a 56 foot Carver docked next to me and boy did his blackwater tank stink. I said something to him about the oder on the dock and he seemed dumbfounded. The next day he mentioned he put bleach down the toilet to kill the odor. And the oder did stop.... Now over a month later the oder is still gone. So, I would think the bleach killed the bacteria that was stinking, but got me to thinking once the bacteria was dead how long would it take for the smelly bacteria to return? Also once the smelly bacteria is dead what should he do to grow the good (not smelly) bacteria? Was his solution a good or bad idea?

OPPS here she comes

 

[foggysail]

Maybe he added a carbon filter into the vent line. That does work

 

[firstbase]

I can see that Peggy has a ticket to this show...she must be out in the ladies room (how appropriate). I'm sure she will be back. Vent lines resurface.....bleach is being added ...oh this will be fun...

 

[ranger58sb]

Maybe he added a carbon filter into the vent line. That does work

Or if he already had a filter and it was way beyond its "sell by" date, maybe he replaced it with a new one.

When our filter needs replacement, our dock neighbors sometimes notice it before we do.

-Chris