Black Tank and Winterizing

PNWtabber

Getting ready for only my 2nd winterizing.  Trailer is a 2018 320S.  I live near Seattle, we rarely get really hard freezes.

Last time I dumped the tanks, I assumed I would be going camping again before needing to winterize, so I added some Happy Camper and a bit of water to the black tank via the toilet.  Probably no more than a couple of gallons of liquid in the black tank (monitor reads 0%).  Not enough to warrant hooking up the trailer and taking it to the nearest dump station.  Can I just put extra anti-freeze in the black tank and not worry about the small amount of water currently in the tank? 

Thanks! 

VictoriaP

That makes it hard to work undiluted antifreeze into the gate valves, so I’d say dump it into a five gallon bucket and pour that down your house toilet. (This is how I did mine the last few years prior to getting a small portable waste tank….which still gets poured down the toilet, but works better with the sewer hose.)

MuttonChops

If it were my rig I would dump the black tank into a bucket.
Then add another dose of Happy Camper and about 1-gallon of RV Water System anti-freeze.  Standard anti-freeze is good for -20F so you could dilute 50/50 (anti-freeze/water) or 75/25.

 . . . . I don't measure mine so my tank is not 100% anti-freeze but also not 50% antifreeze - - - so it's good for at least -10F . . . .

PNWtabber

MuttonChops said:

If it were my rig I would dump the black tank into a bucket.
Then add another dose of Happy Camper and about 1-gallon of RV Water System anti-freeze.  Standard anti-freeze is good for -20F so you could dilute 50/50 (anti-freeze/water) or 75/25.

 . . . . I don't measure mine so my tank is not 100% anti-freeze but also not 50% antifreeze - - - so it's good for at least -10F . . . .

Wouldn't that be comparable to just adding a gallon on antifreeze to the tank, foregoing the dump step? 

MuttonChops

@PNWtabber ;  Maybe but your tank might be cleaner by dumping now as the Happy Camp has been busy eating everything it can find in the 2-gallons of water now there.

dsfdogs

@PNWtabber I too would encourage you to clean out the black tank as Victoria and Craig have mentioned, but be prepared for more "residual stuff" to come out. Before I went through this process at home, I always assumed everything drained well. It's gross. I've had to go through several rounds of adding water to the black tank then draining. A flashlight look into the open toilet is eye-opening as well!

@MuttonChops The fine print on the "standard" alcohol containing antifreeze says it will freeze at 5 degrees F. My lines, p-traps, and tanks have antifreeze in them now (after much much much struggle with the pump not priming). My question is, wouldn't it be safer to now drain all the antifreeze to avoid it freezing? There would still be residue, but seemingly less chance of damage should it freeze.

MuttonChops

dsfdogs said:
. . . MuttonChops;  The fine print on the "standard" alcohol containing antifreeze says it
       will freeze at 5 degrees F
. . . .wouldn't it be safer to now drain all the antifreeze to avoid it freezing? There would
       still be residue, but seemingly less chance of damage should it freeze.

Fine print generally says " . . . product will get slushy/semi-solid at approximately 5F, but will
provide burst protection down to - XX degrees . . . "  With XX varying some by product brand.

For my water systems I do the following.

 = 1 =   Fully drain using the air-blowout method using 35-40 PSI air.
 = 2 =   Only pump 100% anti-freeze into the fresh water pump.
             I installed a tee-valve on the input side of the Pump (Camco Permanent Pump Converter
             Winterizing Kit) .  Only several ounces of anti-freeze is needed to protect the inlet filter
             and pump internal parts.  {to be honest I don't know if any of the anti-freeze stays
             in the pump - - have not researched pump brand winterizing literature}
 = 3 =   Pour anti-freeze into p-traps (gray tank), fresh water tank, and black tank.
             Just small amounts, one gallon between all three.  Goal is to reduce freezing in the
             different tank low spots which includes the gate valves.   Only the fresh water needs to
             be flushed clean in the spring.
 = 4 =   When using the TaB in the cold/snow zones of winter all toilet flushing is from a jug of
             50/50 mix anti-freeze.  To date this approach has worked well.