Is it possible to use antifreeze in holding tank if cannot pump out?

[Jecemis]

So I've made another noob mistake. There are free waste pump out stations in the bay I keep my boat but they're not operational until next spring. There's a pump out boat, too, that will come to you, but they're also closed until the season starts. In hindsight I should have realized that these services were seasonal.

I'm hauling out this weekend. Since pumping out may not be an option, as an alternative can I add antifreeze to the waste tank? Then pump out when I launch in the spring?

 

[Peggie Hall HeadMistress]

Yes, you can add antifreeze to the holding tank...use ONLY the non-toxic marine/rv potable antifreeze...aka "the pink stuff." How much is needed to do any good depends on how much waste is in the tank.

You also need to winterize the toilet. Just pouring antifreeze down the toilet won't work...You need to get it into the pump and channel in the rim of bowl too. You can accomplish that AND put the antifreeze in the tank at the same time: remove the toilet inlet hose from the thru-hull (it would prob'ly be a good idea to close the seacock first) and stick it into a gallon jug of antifreeze. Pump the toilet in the wet mode to pull it through the system and to the tank.

How much is in the tank?

 

[Jecemis]

Thank you for the input... very clear and helpful.

I don't think it was used but maybe a dozen times. I think it should be a couple gallons or so of waste fluids. It's a 5 gallon tank located in the V-berth. I don't believe the wet-mode works anymore, but I'll have it switched to that mode anyway when pumping in the antifreeze.

Is there a particular reason to only use the pink antifreeze? Is it a matter of environmental safety? I know some of the non-organic antifreezes are rated for much lower temps.

I just saw someone in another thread recommend your book. I'm going to order a copy as I' may end up redoing the head next season, or at the very least replace those hoses.

 

[Peggie Hall HeadMistress]

A gallon of antifreeze should be enough. Petroleum based antifreeze is destructive to the soft rubber parts in marine toilets and breaks down hose resistance to odor permeation. The "pink stuff" doesn't.

I think you may find my book useful even if you don't refit the system. I'll be glad to answer any questions it doesn't.

 

[thinwater]

A gallon of antifreeze should be enough. Petroleum based antifreeze is destructive to the soft rubber parts in marine toilets and breaks down hose resistance to odor permeation. The "pink stuff" doesn't.

I think you may find my book useful even if you don't refit the system. I'll be glad to answer any questions it doesn't.

I'm pretty sure you have some of this backwards.

• Both PG and EG are petroleum based.
  
• Both are considered basically harmless to fish and marine life (Google US Fish and Wildlife Service). It is toxic to mammals, but no one is drinking out of a sealed blackwater system.
  
• Both are equally biodegradable. Actually, EG has the slight edge.
• EG is considerably less damaging to neoprene head parts. this can be referenced in any materials handbook. I have done considerable testing or this, both in the lab and in heads. PG is more harmful to many plastics as well.
  
• Permeation. Ethanol (or any other single alcohol) can do this, but I do not believe double alcohols have ever been implicated. Permeation of glycol in elastomeric hoses has been studied extensively. Since EG has better compatibility will all common hose materials, I find this improbable, but nothing is impossible until proven one way or the other.

The most obvious indicator is that no OEM car manufacturer will use PG in their vehicles. There are material compatibility issues and it is a less effective antifreeze agent (more is needed).

Freshwater systems require EG, no question. But only potable systems. If a mammal is not going to drink it, I know of no argument in favor of PG.

 

[Gunni]

If you have a Jabsco read the winterization instructions carefully, you do not rely on antifreeze to protect the toilet. You drain it out.

 

[Peggie Hall HeadMistress]

If you have a Jabsco read the winterization instructions carefully, you do not rely on antifreeze to protect the toilet. You drain it out.

Well of course you do. Not only Jabsco toilets but any toilet. And you don't "drain it out"....the antifreeze goes THROUGH the toilet to get rid of any water left in the intake line, pump, channel in the rim of the bowl and the hoses--which can't happen if you just pour it into the bowl--and then into the tank.

 

[Gunni]

Well of course you do. Not only Jabsco toilets but any toilet. And you don't "drain it out"....the antifreeze goes THROUGH the toilet to get rid of any water left in the intake line, pump, channel in the rim of the bowl and the hoses--which can't happen if you just pour it into the bowl--and then into the tank.

Negative. All lines get disconnected from the toilet, including the discharge connection (loose the pump fitting) and the bowl drain, stroke the pump to clear the pump and you are done with the toilet. No water, no freeze. Per Jabsco.

Winterizing your flush intake and discharge hoses are install specific but using the toilet to 1) pump AF to the discharge hose system by pumping a bowl full of AF is easy. Flip the overboard valve to AF that side. 2) Pull the raw water hose loose from the toilet (heckuva lot easier than pulling it free of the thru-hull) funnel AF into the hose and cycle the thru-hull a few times to get AF into the fitting and done. 3) My pump-out hose connects to the holding tank bottom for some reason, so that requires an AF application from the deck fitting to assure that any water is winterized.

 

[SFS]

Gunni, I thought ALL pumpout hoses would connect at the bottom of the holding tank. How else would a pumpout completely empty the tank?

 

[Peggie Hall HeadMistress]

Negative. All lines get disconnected from the toilet, including the discharge connection (loose the pump fitting) and the bowl drain, stroke the pump to clear the pump and you are done with the toilet. No water, no freeze. Per Jabsco.

Pulling antifreeze through the system eliminates the need to disconnect all the hoses--and then have to reconnect 'em all in the spring...but if you want to do all that, it's ok with me.

I thought ALL pumpout hoses would connect at the bottom of the holding tank. How else would a pumpout completely empty the tank?

The so-called "standard" discharge fitting location IS at the bottom of the tank. But when there's enough clearance above the tank--at least 5"--putting it on the top of the tank, with a pickup tube inside the tank that goes to the bottom, is a better way to do it because that eliminates standing waste in the discharge line.

 

[Gunni]

Gunni, I thought ALL pumpout hoses would connect at the bottom of the holding tank. How else would a pumpout completely empty the tank?

A top penetration with a dip-tube to the bottom of the tank. As Peggy notes anything you can do to eliminate hoses with standing effluent makes for an improved waste system. In general I don't like hoses connected to the bottom of tanks. Valves maybe, not hoses.

 

[Daveinet]

Salt also works.

 

[MitchM]

1) "Both PG and EG are petroleum based. ...Both are considered basically harmless to fish and marine life.." ?
who ever thinks EG 'the Green STUFF is non toxic has never seen someone else's pet die from seizures after the poor thing accidentally ingested it. Ethylene glycol is poisonous to humans and other animals, and should be handled carefully and disposed of properly. Its sweet taste can lead to accidental ingestion or allow its deliberate use as a famous spousal murder weapon.
2) Propylene glycol, PINK STUFF on the other hand, is considerably less toxic than ethylene glycol and may be labeled as "non-toxic antifreeze". It is used as antifreeze where ethylene glycol would be inappropriate, such as in food-processing systems or in water pipes in homes where incidental ingestion may be possible. As confirmation of its relative non-toxicity, the FDA allows propylene glycol to be added to a large number of processed foods, including ice cream, frozen custard, salad dressings and baked goods, it is now a main ingredient of E-cigarette liquid (E-liquid or E-juice).
3) '" disconnect all hoses in/out of the head ? " For 35 years on 3 boats and 2 RV's I have been winterizing my fresh water water systems, heads in boat and RV, my RV and boat holding tank and macerators and my yan mar diesels with Pink Stuff. pump it through, no hose disconnects. no hose damage. no impeller damage. after a rinse out of the h 2 0 systems in spring, everything is fine.

 

[Bill Roosa]

What shape is the tank? a square tank with vertical sides will have problems with frozen fluids. If the tank does not have vertical sides (for any reason) then the ice will freeze but it will not force the sides apart. It will just slide up the sloping side and then melt in spring. A square tank on an angle does not have vertical sides. By vertical I mean less than 15ish degrees from vertical.
For the record I have made this mistake about 7+ times since I bought the boat about 7 years ago and have had not problems with 1/2 full tanks. The tank is steel BTW.
Good luck

 

[Davidasailor26]

who ever thinks EG 'the Green STUFF is non toxic has never seen someone else's pet die from seizures after the poor thing accidentally ingested it. Ethylene glycol is poisonous to humans and other animals, and should be handled carefully and disposed of properly. Its sweet taste can lead to accidental ingestion or allow its deliberate use as a famous spousal murder weapon.

Totally agree that EG is very toxic to mammals, which is compounded by its attractive sweet taste. But not all animals and environments are the same, and mammals are hopefully not drinking the contents of holding tanks. There have been studies showing that the toxicity of EG in a marine environment is not significant, for example: "The data collectively show that EG is not persistent in air, surface water, soil, or groundwater, is practically non-toxic to aquatic organisms, and does not bioaccumulate in aquatic organisms." (http://www.sciencedirect.com/science/article/pii/S004565350000148X)