Frozen black water

[acenjason]

OK, so I am living full time in my beloved 1975 D21 Winny in the mountains of Colo. I recently had surgery and forgot to put RV tank antifreeze in my waste tanks. Now my black water tank is completely full and frozen solid. I have looked around at things to do to fix this and thought I should ask. I am thinking of putting a small 1500 watt electric heater under there on Saturday and use the heat gun on the valves to loosen them. Also, I heard you could dump rock salt down the toilet and it will sink and thaw the ice like salt thaws a side walk. Does this work? We use a lot of the store bought ice melt. Could I dump that down? I would love any help. This is a major bummer when recovering from surgery. Not having my bathroom work sucks

[DonD]

http://www.rvdoctor.com/2012/02/frozen-rv-holding-tank.html

[TerryH]

Don't know if this helps,BUT-
Heat gun on the dump valve will let you use the valve, but it won't dump frozen waste. May also cause additional problems - selective but unwanted specific heating, seal damage, leaking ,etc.
In the Arctic and NWT when a truck froze we used to (years ago) tarp the engine and use a propane "torpedo" heater to thaw out.
Tarp would direct the heat to a desired point (engine block)  but allow excess heat to escape, so no or minimal damage to rubber/etc. parts.
Salt,etc.? don't know. You may be too late, again, don't know.
Personally, I'd be very reluctant to place an electric heater anywhere under your rig unless you were continually monitoring it.
My opinion.
Terry

[TerryH]

Further to the above - thawing your valve will not help your "frozen solid black water tank". Thawing your tank will thaw your valve.

[LJ-TJ]

   
• I think your first idea is the best. There is no quick fix. Possibly get a card board box the size of your black water tank and valve and but it up under and around your black water tank, seal it and then put a little electric heater in side the box. You've got to find a way to seal the tank off in order to get heat around the tank. I don't think a heat gun will do the trick for you and the direct heat may cause you more trouble than it's worth. I don't believe pouring salt down the trap will do all that much good. You've got to get heat around the tank.

[Rickf1985]

I agree with the close off the tank area theory. You have to isolate the tank from the cold air to start with and then put a small heater in there, SMALL heater. This is not going to happen in two hours if you have 30 gallons of frozen waste. More like two days. Isolate and insulate the dump valve as much as possible and the heat from the warmer waste in the tank hopefully will thaw that also but it is best if you can include that in the enclosure you build for the tank. Good luck.

Rick

[eXodus]

Get a self Sticking Tank heater. Holding Tank heater, Tank Blanket.


You maybe get the problem also in the Future, this would be a permanent solution.

[LJ-TJ]

Just got to thinking that if your full timing and are anchored to shore power for a bit. Go to Manards and pick up some 4X8 by 2" blue foam sheet and build you box out to that. It will be insulated and hold the heat well and keep out cold.        ?

[tiinytina]

Salting the tank will work over time to thaw it as it lowers the freezing temp thus thawing the ice. Make sure to drain it asap once that happens....  Skirting the RV with any material will help.. the blue sheets of R12 are great and easy to work with.  running a cord under and setting up a couple of old fashioned incandescent 40-60W light bulbs will keep temps above freezing usually once wind etc is not a factor.  Heat tape can be used as well. 
tina

[acenjason]

Thank you everyone for your ideas.

UPDATE:

So, the weather warmed up a bit so I put a big plastic tub under my dump valve and opened it. The tank on the 75 D21 is tiny so a tub can hold the waste without any problems. Over the last few days the tank have been thawing slowly and draining into the tub which I dump daily. I has been helping the thaw by spraying windshield wiper ice melt that comes in a spray bottle from Walmart down the toilet onto the top of the ice. I figured if it is OK for windshield wipers than it should be OK for the rubber and plastic of the tank. It has been working slow but sure. I figure I have about 2/3 of the ice out. I am thinking of closing the valve and then adding 2-3 gallons of the RV tank anti freeze. Then hopefully my tank will dump normally and completely.

[tiinytina]

AT this point maybe add a pot of two of boiling water every 30 min or so.. add a little table salt to each pot...  70 today here in MD  snow predicted for wednesday afternoon... LOL..

[Rickf1985]

What Tina said but leave the dump valve closed and use a LOT of salt.

[legomybago]

Over the last few days the tank have been thawing slowly and draining into the tub which I dump daily.

Ewwwweeewwwweeee......

[pvoth1111]

How is black water getting into your tub....my black water and grey water tanks are NEVER...NEVER...NEVER...EVER open at the same time.....my grey water is open all the time and black water gets dumped and cleaned every week or as needed.....I take care of both tanks really well....they get bleached and cleaned every week and rinsed till totally clean....

As others have said get a small heater (short term) and some how install electric heat tape or same to both  tanks........or avoid cold as I do

[acenjason]

Well, in the 1975 D21 the two tanks have separate hose hook ups and dump valves. That's how I can have one but never both open at the same time. And the black water was drained by gravity into the tub placed under the valve. I am going to see if the antifreeze works and buy aheat tape. The tanks are very small on a 75 D21 so I can use a lot of antifreeze and heat tape and dump every week as usual now that its thawed.    I learned my lesson. Not having a working toilet sucks 

Thanks again everyone for the ideas. 

[pvoth1111]

a non working toilet does suck....are you parked in a campground, resort....or other??

no working facilities?