Holding tank emergency!

[hmgiffor]

The cap on the holding tank of our S2 sail boat is rusted on and the switch to drain it overboard broke off, so we cannot pump it out. The tank is extremely full and has started leaking out the vent and has even began coming back up the head. We are off the boat for the summer so we have some time to figure out a plan.

We assume it needs to be removed and replaced but haven't found any solutions through septic or boat repair companies, etc. Are there companies in St. Petersburg Florida that can do this type of job. If not, what would need to be done in order to avoid an explosion. This plastic tank is bulging and its pieces are corroded.

Any advice is welcome. Thank you for your time!

[Steven UK]

My worst nightmare... Peggy may scold me, as she has done before. But I would, run away, burn it, sink it, sell it... I would be too afraid to sleep on that boat. I would rather have poltergeists on board

[Bleemus]

Bring the boat to the pump out station and have it pumped out. It's easy. If you dump it in St Petersburg harbor you are breaking the law.

[Wotname]

Originally Posted by hmgiffor

The cap on the holding tank of our S2 sail boat is rusted on and the switch to drain it overboard broke off, so we cannot pump it out. The tank is extremely full and has started leaking out the vent and has even began coming back up the head. We are off the boat for the summer so we have some time to figure out a plan.

We assume it needs to be removed and replaced but haven't found any solutions through septic or boat repair companies, etc. Are there companies in St. Petersburg Florida that can do this type of job. If not, what would need to be done in order to avoid an explosion. This plastic tank is bulging and its pieces are corroded.

Any advice is welcome. Thank you for your time!

If the tank is bulging from excessive pressure in it rather than bulging from just being too full, then you have to release the pressure ASAP.

Drill a small hole in the top of the tank or as near to the top you can get or in the cap - anywhere is better than nowhere!

Any problems occurring due to this new hole is way better than having the tank bust uncontrollably!

[Wotname]

Welcome aboard CF, hmgiffor; tough first post!

[Mike OReilly]

Can you remove the deck fitting? I understand the cap is rusted on, but surely you can pry up the deck fitting, probably destroying it in the process, and get to the exit pipe. Then, pump it out, and reinstall a new deck fitting (as you have to do anyway).

[peghall]

I see you're a brand new member here...welcome aboard! You're not the first to start out with a MAYDAY...you won't be the last. And we're all glad to help!



It's essential that you be able to pump out the tank. But there are problems to be solved before it'll be possible to do that. You said the tank is so full that that waste is leaking out the vent and going back into the toilet. The word leaking tells me the vent is at least partially blocked--it would be "overflowing" out the vent if it weren't) and the system is so pressurized that the pressure is forcing tank contents out wherever it can go--the vent and the toilet.. So the first thing we need to do is clear the vent (expect a spew when you do!)



The vent thru-hull is the most common location for a vent blockage. Use a screwdriver blade, ice pick--whatever works--to scrape out whatever's in it. If that's the only blockage, expect a spew. Hopefully you don't have another blockage in the other most common location: the other end of the vent line--the vent fitting on the tank and that end of the vent line. That one's gonna be tougher to clear without dumping the tank into your bilge...and we definitely don't want to do that!



If that doesn't work, I'm gonna need a lot more detail from you about the plumbing, valves etc to help you figure out how to relieve the pressure without putting the entire contents of the tank into your bilge (or wherever the tank is located). So how 'bout sending me a private message (just click on my name at the left of this post to do that) that includes your email address and we'll take it from there...most likely on the phone. (I don't charge anything to solve problems, btw.) Meanwhile, don't remove any hoses or poke any holes in the tank!


--Peggie

[thinwater]

Everything Peggy said. Let's hope the vent was not too hard to clear.



Failing that (and I would try hard), you must focus on getting the lid off. Penetrating oil. I would be leery of heat, since there are quite likely be explosive gases on the reverse side. Peggy warned of a "spew": if the vent is blocked and the cap comes off, this spew will come from the bottom and can be extensive and spectacular. Much worse than the vent spew.



If I could not get it loose, I would drill a hole in the cap and let her blow. I could then take the hose off (only a teacup at most above it), connect the pump-out to that, and pump the tank dry. Some fun. Just remember that like changing diapers, it's just poop. Also, everything we have described is MUCH better than having it blow into the bilge.



Then back to the business of fixing all that is broken. And swearing a blood oath that you will never again pump into that system that is not fully functional. That seldom ends well.

[HopCar]

Since you are new to the forum you need to know that Peggie literally wrote the book on marine sanitation systems. https://www.amazon.com/New-Get-Rid-B...MAWXKV13CD1AG7

Thinwater does research and writes for Practical Sailor Magazine.

You’ve got the answers from the real experts.

Once you relieve the pressure, you may find you can unscrew the cap.

[rbk]

If you have some access to the vent hose I’d try and clamp a section and install a couple of T fittings so you can isolate the vent hose from the tank (closer to the tank the better) and try and blow/flush out the vent to deck hose and depressurize the tank into a bucket rather than on deck, then pull it the deck fitting and cut the hose as mentioned above. Or just let it rip

[GordMay]

Greetings and welcome aboard the CF, hmgiffor.

You're getting some really expert advice; so I'll just wish you good luck.

[Bleemus]

Yo have a blocked vent hose. Clear the block and get to a pump out station.

[Tetepare]

Thank god he has all summer to come up with a plan for an overfilled holding tank. Bet there are no chemicals in the tank. Now who wants to drill that hole?

[a64pilot]

Way I see it is getting stuff all over you is like running aground.
It’s going to happen eventually, only thing you can control is how bad is it.

[pcmm]

Originally Posted by hmgiffor

The tank is extremely full and has started leaking out the vent and has even began coming back up the head. We are off the boat for the summer so we have some time to figure out a plan.



Any advice is welcome. Thank you for your time!

I would say the opposite. You definitely DO NOT have all summer to figure this out. What do you think is going to happen to that tank as the contents are heated though the hot summer season? You're likely to come back to a worse mess! I would remove the hose from the bottom of the deck plate fitting and replace the deck fitting with a new one and get it pumped ASAP. Have them rinse out the tank while you are at it. DO NOT leave this all summer, you will have a worse mess to deal with after a summer of "fermentation"!!!!