Winterizing partly full black tank?

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Frank B

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Yes. I just dumped it in the toilet being careful to do it slowly. We don't put TP in our holding tank, so it was pretty much all liquid. Was a bit smelly, but the ventilating fan in the bathroom got rid of that in short order.
 

Frank B

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Yes. I just dumped it in the toilet being careful to do it slowly. We don't put TP in our holding tank, so it was pretty much all liquid. Was a bit smelly, but the ventilating fan in the bathroom got rid of that in short order.

Not here in Canada. A lot of the smaller municipalities offer a free RV dump, but not the city of Calgary. Just nothing in this area at all free or otherwise. Even the paid sites are filthy and the flush water seldom works. We usually dump our trailer well before we get into town to avoid that problem. It just didn't happen this year, however.

In any case, the whole object of this was to avoid taking the trailer out of the yard as it is so hard to get it back in again.
 

Frank B

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Do you know of anyone with a portable tank that you could dump it into and take that somewhere to get rid of it? That would be a valid option.
I have a 10 gallon sewage tote, but I would have to load that in the back of the pickup, and then take it somewhere to dump it. The bucket dump was much simpler in this instance.
 

billwild

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Good for you for finding a solution. Now a days, it is almost impossible to find someone to replace or repair a black tank.
 

Ray-IN

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Thanks, all. The bucket dump worked just fine. One of those eminently practical solutions that just didn't occur to me. I kept trying to complicate it. 😕
Wise choice! Adding anti-freeze into the tank would not protect the 3" pipe and dump valve area, there is no method to mix in the anti-freeze. This means the pipe WILL freeze and burst.
 

Gary RV_Wizard

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Adding anti-freeze into the tank would not protect the 3" pipe and dump valve area, there is no method to mix in the anti-freeze. This means the pipe WILL freeze and burst.
I have to quibble with this. Antifreeze in the waste stank diffuses throughout the liquid and reaches the tank side of the valve. The liquid may get slushy enough that the valve won't operate easily, but it shouldn't freeze or suffer damage. The open question is the amount of RV antifreeze added vs the volume of the fluids in the tank.

That said, my preferred method would still be to empty the tank.
 

Ray-IN

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Gary, the majority of cheaper RV antifreeze brands state on the label 'do not dilute", the reason is the formulation method, it does get slushy as you said but does not expand like water when frozen. The brands which are -50° and lower may be diluted according to their label.
Nearly all RV sales lots leave holding tank dump valves open during storage for this reason, no liquid to freeze and cause damage.
 

IBTripping

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Sep 19, 2018
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Virginia
I've put pink antifreeze in the grey and black tanks in freezing temperatures and never had the discharge pipes freeze. FYI - just picked up some Preston RV antifreeze which is good to -100 degrees compared to the the regular and cheaper -50 RV antifreeze. Walmart was out of the cheap stuff.
 

KrisMI

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Jul 18, 2022
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I did this twice. Trailer parked in Michigan. I dumped whole gallon of the pink liquid inside. Never experienced any problems because of that. And then I bought the Rhino Portable RV waste holding tank. So now I just tow it away.
 
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