4588 Waste Holding Tank (again!)

[Jmason]

I replaced the holding tank on my 1990 4588 in 2016. The yard hauled out the boat and cut out the guest sink vanity and removed the back wall to remove and replace. Vaccuflush was all renewed and connected and all hoses replaced. All went well until last week. I knew the tank was approaching full after 2 weeks aboard at the slip. My wife called me and told me she heard something "pop" on the last flush. When I got back I was surprised to find that the "Tank Watch" light actually did work. The tank was completely full. When I got into the hold I found a mess and cleaned it up. Also found a mess under the shower pan and cleaned it up. Had the tank pumped and rinsed and pumped (twice). A tech came in to inspect and finally identified that the tank had cracked along a lower seam.

I suspect that the yard that did the original install failed to vent the tank properly and relied on the single "odor" filter line as venting. Suspect that they did not understand the power of the vaccuflush. Also suspect that pump outs every 2 weeks with insufficient venting may have taken a toll on the tank flexing it due to limited venting.
I have contacted the yard and am awaiting response to arrange replacement.
I think that the OEM tankage was 48 gallons. Wonder if there is 50(plus) would fit and if there is a stock/OEM available or If it must be custom?
Welcome input on this subject.
Smitty and Ksander were very helpful in the past.

[smitty477]

Hello Jmason - perhaps try posting on the Trawler forum.
It is easier to do pics and PM there and there are a few 45/47 owners on the site.

[Jmason]

Not happy with this new format. Where do I find the TRAWLER FORUM? It does not show up on this Forum listing.

[smitty477]

Sent you a PM - I am not likely to be online here much.

[ksanders]

What we did was to replace our holding tank with a much smaller holding tank and a Raritan Hold-n-treat system using their electroscan system.

I really like the idea of treating our waste (where legal) and holding it onboard when appropriate.

[Jmason]

New format SUCKS! Even more than the last change!
The holding tank issue remains a concern. I am a quasi live aboard two plus weeks in a month. I am still pursuing replacement of the tank (again). I will be making sure that there is adequate monitoring of content and venting as well as frequent pump out. Additionally, I will pursue warning monitor improvement and delicate education of users to assure that there is no repeat of this problem. I suspect that there was insufficient venting and allowance for over-fill.

While I would love to treat the sewage to allow for ECO friendly discharge, it is impossible.

[Norton_Rider]

Not happy with this new format. Where do I find the TRAWLER FORUM? It does not show up on this Forum listing.

http://www.trawlerforum.com/forums/

[Jim_Gandee]

Jmason,
i installed a suction relief valve on my holding tank to prevent flexing and collapse during pump out. Works great and easy to install.

https://www.northeastsanitation.com/dometic-sealand-tanksaver-relief-valve.html?gclid=EAIaIQobChMI-viZzNjF1wIVBP5kCh3KPAqzEAQYAyABEgIN9_D_BwE

[Ahaua]

Jumbo, I need to install one on my boat. Come over and do it for me....I hate crappy jobs....

[Jmason]

Ordered a complete Vacuuflush rebuild kit and the suction relief valve. The commode will be removed during the process of the tank replacement so it makes since that it should be rebuilt as a precaution.
Also having the vent and vent line replaced w appropriately sized hosing. Also plan to leave the pump-out camp loose as the tank reaches 3/4 full to make sure that it vents without expanding.
Really doubt that the cracked tank was related to vacuum pump-out once every 2 weeks as the original problem was noted by a pop sound and spewing all about the hold area. (Really tough to clean-up but I got it done.

That area beneath the shower pan is also a tough clean but I got it done and SANITIZED.
Got the boat to the yard to day to start the project!! Weather was great, water flat, barely any wind.

[Jmason]

Update:
Tank is now out and there was a crack caused by over pressurization. The vent was reportedly clogged with paper. Awaiting the tank fabricator to get replacement to the yard. The vacuum relief valve will be
installed along with new vent filter, vent hose, and vent exterior fixture. The Vacuu-flush rebuild kit arrived and I dropped it at the Yard so that the head will be rebuilt and duck valves all replaced.
Since it's up in the yard, I'm having the bottom painted as well.

[capnken]

the vent system on the holding tank is only 1/2" and intended for regular open electric toilets. When I converted to Vacuflush I created a 1 1/2" vent from an irrigation one way valve I got at Ace hardware. The top of the tank already had a capped off plug which I screwed the valve into. Nice thing about the valve is that it is a spring pressured ping pong ball that seals tightly, not a 'flapper' diaphragm valve like the installed on later Meridian OEM Vacuflush systems. Vents fantastic and no odors leak out. See the attached pics that show it in place. I cut an access panel in the floor of the liquor cabinet and now I have a nice access to get at this area. Good luck!

[rbcooper]

Capnken.

I guess I'm a bit confused, are you saying you installed a vent with NO hose running to the exterior? I get it that the spring loaded valve will resist a degree of pressure but what happens when the tank is over filled? Seems like it could generate quite a mess.

RB Cooper

[capnken]

I have not added a hose but the valve is 6" to top above the tank.... and I never overfill...but if you want you could vent outside.