Realistic ways to thaw out a frozen tank

[billyinvt]

Wow Dave! Now that's some mighty expensive solution. At the time of the original posting the tank was a solid block of frozen sap. As Matt suggested, the ice in the tank has served to keep all new sap nice and cold and fresh, So I've just been adding to the tank as the block slowly shrinks. Should be gone after today's 50 degrees.

[Daveg]

A sinking stock tank heater from TSC is $32 and is recommended for use in 100-300 gallon tanks. I used one in a plastic 60 gallon drum: just fine. However, you will probably need a $10 space heater from ***mart to thaw the valve. That or 2 gallons of HOT water slowly and strategically directed at the moving parts. All thawed sap will need to be processed immediately or it will go bad very quickly.

[Bricklayer]

I've been dealing with frozen cage totes last couple of years. What I've learned is that the totes take a lot to freeze solid. If you catch them quick enough you will notice they usually freeze about an inch or 2 around the outsides of sap. It looks like a solid block but it isn't.
What I do is get a hole broke in the ice block through the lid. I use a piece of 1" copper pipe about 3' long. It seems to do the trick.
I then put my sap transfer pump intake line in the hole and fire pump up. I just recirc the sap through the pump and put the pump line under the ice deep into the tank. It will create enough turbulence to weaken the ice eventually. I usually run it for an hour or so and I'm good to open the valve. Ice in the tank is good to have to keep sap cool. So I leave as much as possible. I drilled a hole in the outside of the ball in the valve to drain it out when it's closed. If you have the gate type valve that is not possible.

[Havingfun]

What if you ran a aquarium air pump and placed the air line at the bottom of the tote. By introducing air into the tote it should reduce icing by constantly agitating the water.

[FarmerKJS]

If my tank is only frozen around the edges a few inches thick, I can take and shake it up with a skid steer or a bumpy road. This breaks up the ice enough that I can open the valve and pump out the sap.

If it is frozen more than a few inches, I just bring it into our heated shop for a day or two and it gets it to the point that I can use the above method.