Replacing holding tank?

[Steve McGill]

From all that I have read (Peggy Hall, Headmistress), if you have any vent much over 4 feet in length you loose most if not all benefit.
I believe the best option is to increase the existing vent line size to greater then 1" and to move it out of the current stanchion.

Steve

[Stu Jackson]

Tony, the basic idea for the larger vent is to avoid having the smell inside the holding tank in the first place, based on Peggie's description.  I forget whether its anaerobic or aerobic, one of them makes the smells because of too little air in the holding tank.  Somewhere I posted this earlier, and I'll try to find it and link to it, but you could do a search on "Peggie Hall" use the "s and find it yourselves.  Therefore, aft or forward makes NO difference.  The shorter the length, the better.

Steve M, I agree, question that has been raised, without a specific answer is where does the through hull at the outboard end of the new larger vent go?  I have contemplated putting it just below the rub rail, as described in the earlier idea of running the vent to the V berth port side.

[Chris Martinson]

All:

I've been out of touch.  I have previously replaced all of the hoses.  I do think the tank is permeated.  After 2 years of new hoses and a new head - I still have a smell and need to work on the vent.  I thought I had read where someone increased the hose size and put a clam shell type vent on the deck but have many questions about it.  I have also thought about adding another vent but haven't figured out the routing on the MKI.

Looking at the tank - it appears to be a straight forward task but nothing is ever as it looks on a boat.  Looks like only hose connections and it should come right out...???

another question - what works for cleaning and killing germs in storage spaces...I've been using a cleaner with bleach but want to know what works for others...when I get the tank out I want ot clean behind it well....

Thanks

Chris Martinson
More Therapy
hull #945

[Stu Jackson]

The link to Peggie Halls' original article is: http://c34.org/bbs/index.php?topic=1198.0  A search on Peggie Hall found it a few threads down in the search results.

Chris, we need to start dealing with some specificity in the location and design of the new thru hulls required if we want to relocate the existing vent, regardless of the vent line size, anywhere near the port side of the boat and anywhere near the existing vent hose routing.

On the Mark Is, I believe that there is adequate space to run the new larger vent line up through the enclosures that now house the existing 5/8 inch too small hose.  The question is, once the new larger 1 inch hose gets above the top of the seat cushion line, where does it go, and what does it connect to.

From my readings, and what I would do if I was doing it to our boat, I would take the ideas incorporated in this thread, and put a big MF-ing 1 inch thru hull right below the rub rail, and connect the new 1 inch vent right there, following the line it currently runs before it turns left and aft to the stanchion base.  Yes, there'd be a 90 degree elbow to the thru hull, but the line would be bigger to make up for it.

I can find no reason to use a clam shell cover, unless we're planning on getting rolled over (I don't bury my rail and I've been sailing here for a long time.)  The thru hull as I have described it would be at about the widest place on the hull.  Sure you could put one OVER the thru hull, but wouldn't that serve to reduce the amount of air getting to the vent, based on the basic principles that Peggie recommends?

OK, I've designed it, now all I have to do is install it, take pictures and write it up - how about one of you beat me to it!   

As far as other doors are concerned, I suggest you buy Peggie's book.  I don't know her, only rare Internet correspondence, but that's why she wrote the book in the first place.   You could also do a search here on "odors" and "germs" and find what you're looking for from earlier conversations, if you haven't had a chance to do that already.  I find a lot of answers to questions by using the search engine, and take some grief for suggesting it to others, but it does work.  I try to help narrow searches  if someone mentions they can't find something specifically simply because I hang out here almost everyday.  Nice neighborhood, too.   

Tank removal:  Some earlier replies on this thread have mentioned tank removal, but I don't recall if there was any specific method of doing that, and what it entailed, other than my supposition that the macerator pump and all hoses had to be removed.  Even with that, I'm not sure how mine would come out of the hole.  Can anyone who has done it help out a bit here?  Thanks.

[Jeff Kaplan]

chris, i was the one who increased the vent hose size and drilled a hole thru the deck, installed a mushroom type fitting and covered with a clam shell. eliminates the stantion post vent setup. my e-mail and phone # are listed on this site. you can call me for added info. as posted above, i did change the tank as it was a major cause of the stink...jeff

[Craig Illman]

Stu - a very brief tank removal description, as best as I can recall it. I, with some experienced help, replaced mine last October.

First step, over to the pumpout and did a triple flush, with about five gallons of fresh water between pumps. then, back to the slip. I cut the tabbing that supported the plywood bulkhead on the aft and port sides. It was actually pretty quick and easy. I think the took of choice was a sawzall blade about 6" long on a small handle. I think we disconnected the macerator at the tank (with a wet/dry vac standing by) by cutting through the tank fitting. I had already purchased new fittings anyway. Then, it was just a matter of cutting the macerator wiring and removing the hose going to the thru-hull. The tank then lifts right out. I thoroughly cleaned the area with a bleach/soap solution.

I still had some Odersafe hose left from doing the run to the head and vent from the previous season. We replaced all the tank fittings and had to re-attach the macerator to slide it all in as a single unit. I tried to put a piece of "fuel diaper" between the tank and stringer below, but it's a real tight fit between the tank with it's 90 degree vent fitting and the settee cover.

After the tank was situated so the vent host wouldn't hit the cover, my friend demonstrated how to re-tab in the plywood bulkhead pieces.

The old tank was pretty rank, with a layer of crud in the bottom that I think no amount of flushing would have ever removed. My workmates with RV's talk about both dumping in detergent on the trip home to slosh around and somehow getting a pressure washer hose to stir things up. I don't think either of those solutions would work for us.

I'm currently on a regimen of fresh water flush, white vinegar at the return of the trip and, I think, the Raritan stuff that has good bacteria to help naturally break down things.

Craig

[Chris Martinson]

Craig:

I am wondering if my tank installation has already been modified....what tabbing are you referring to?  I only have vertical plywood "bulkheads" on each end of the tank that hold it in place and my macerator isn't connected directly to the tank but from a fitting to hose to the macerator.  Next time I am at my boat - I will try to take a picture to compare and see if my installation has been modified.....thanks

Chris

[Craig Illman]

Chris - I wish I had a picture as well, but won't be up to the boat until next weekend. On the aft end of my tank there is a 1/4" piece of plywood that was glassed with thin mat to the bottom and starboard side. Also on the port side there was another thin piece of plywood about 4" H x 18" L glassed with thin mat to the bottom and around to the aft piece of plywood.

Yes, my macerator is connected to the tank with fittings and a very short piece of hose. Sorry for the confusion. I'm pretty sure we sacrificed the old fitting when we took the tank out. We needed to attach the macerator to the new tank when it was put in. There wasn't enough room to slide the macerator and hose onto the new fitting with the tank in place.

Craig