QUESTION:
In winters past, we parked our trucks inside overnight, mainly to prevent the water tanks and, more importantly, the water pumps, from freezing. We don’t have that luxury anymore. We have looked into a chemical additive in the water to drop its freezing point; we have looked at installing water heaters in the tanks, but our budget is tight right now. What advice do you have for dealing with water tanks and water pumps in freezing weather?
Incidentally, we live in the Southern Mountains zone, where winter low temps average about 20 degrees and winter high temperatures average 30 and 40 degrees.
George Sieburg
Weaverville, N.C.
ANSWER:
Great question. Just when we thought we had an answer, we checked with some of our cold-weather customers who operate in conditions similar to yours. Here are some solutions for you, in no order of preference or cost of solution.
Methanol
Methanol is known by several names. It is called methyl alcohol, wood alcohol, wood naphtha or wood spirits. It is used as a solvent, as an anti-freeze in pipelines and in windshield washer fluid. Here’s how to use it effectively in your situation:
1 Drain all the water out of your system.
2. The accompanying chart shows how to mix the methanol with the water depending on the temperature.
3. Operate the pump to make sure the methanol mix runs through the entire system. It’s no fun waking up to a pump that has been left with water in it overnight to find it has frozen and cracked the housing. Complete circulation of the methanol mix won’t take long. Once you are sure the methanol is mixed throughout, your system should be protected as the temperatures dip overnight.
Methanol facts:
1. Methanol is toxic. Drinking 10 ml will cause blindness and 100 ml will cause death. So don’t leave it where pets or children can reach it.
2. Yes, this is the same stuff that was used as motor fuel during the oil crises of the 1970s. It was readily available, had a low cost, and was relatively safe for the environment. However, as gas prices slumped and supplies went up, methanol lost its appeal.
3. Methanol is biodegradable.
4. Methanol boils at 148.4 degrees F at sea level and freezes (called melting) at -142.9 degrees F.
Due to its toxicity, this solution must not be used in freshwater tanks. Your only salvation for those tanks is to use heating elements and valve heaters. Heating elements can be plugged in at night and installed in one of the tank fittings. The water will be kept warm overnight for use the next day. As for the valves, heating collars run off the truck radiator and prevent freezing.
Salt brine
Another method of avoiding the deep freeze in your tank is to add salt brine. This is a simple process of adding rock salt to your water tank. Salt monitors are available to determine the proper ratio of salt to prevent freezing while keeping costs down. Search for information on the Internet or talk to your pump supplier for suggestions.
Magnesium chloride
Magnesium chloride is another anti-freeze solution. This chemical is commonly used in mining operations that continue to operate in freezing temperatures, usually below zero. For every gallon of water, add one gallon of magnesium chloride, creating a 50-50 mix.
SAVE YOUR PUMP
One of these solutions will be more affordable than the others for your specific situation. Find out what works best for you and you’ll avoid costly damage to your pump.
This table shows the percentage of methanol necessary per tankful of contents to keep your waste tank and pump combination from being damaged when sitting in freezing temperatures.
