Water in the Gas
Nov. 11th, 2013 05:07 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
hafocNothing makes me feel self-righteously wise better than finding out that one of my silly superstitions is correct. To wit: Keep your gas tank as full as possible in winter to avoid getting water in there.
My theory (which turns out to be correct) was that much of the water in your gas tank condenses out from the air. You always have some air in the gas tank. As temperature rises and falls the air expands and contracts, moving some old air out and some new air in. Moisture comes in with the new air, condenses out inside your tank, and there you are, water in the gas.
My friend Tom, who comes from a family that owns gas stations, told me you should never buy gasoline at a station that's receiving a shipment from a tanker truck.
"Because the gas station might explode?"
He laughed at me. "No. Well, actually, if it's ever going to explode it's more likely to when they're getting a shipment, but when does that ever happen?"
There isn't, or wasn't, a downtown Birch Run because the gas station went up while they were taking in a shipment one day, but I didn't mention that. "What's the reason, then?"
"There's always sand, grit, water. You know, miscellaneous crud. There's always some of that in the bottom of the gasoline tank. When they're filling the tank from a truck it stirs up all the crud. You fill up then, you get the stirred-up crud pumped right into your gas tank."
Makes sense to me.
Once you DO get water in your gas tank, you have to put alcohol in there to get rid of it. Maybe the best way is to buy a tank of gasohol, gasoline plus 10% ethanol. Ethanol mixes well with water (that's what vodka is, maybe 40% ethanol and 60% water) and it mixes with gasoline, so burning a tank or two of that will mix the water into your fuel and burn it out of the system a bit at a time.
Sometimes I add gas line antifreeze, which is alcohol too. There are two kinds they sell for that purpose. The slightly cheaper is methanol, wood alcohol. It will mix with the water and prevent it from freezing, which is good, but it doesn't mix well with gasoline, so it won't work the water out of the system. Isopropyl alcohol costs a bit more but will make that three way water/ gas/ alcohol mixture and get rid of the moisture once and for all, so I think it's better. They don't advertise which they're using very much, though. You have to read the fine print on the bottle most of the time.
The stuff works pretty well. Witness another story a friend told me, about this AMC Hornet wagon he drove once.
The Hornet had many delightful design features, including a full size spare tire (as they all were, then) that was mounted in a slanted well in the back, under the floor. I don't know why they did it that way, I don't know why AMC did anything they did. When water leaked into the back (and some water always leaks in) it would get into that well, as the lowest possible point. But that was OK. As with many things in cars, there are drain holes to get rid of any water that happened to accumulate in there.
Fine and dandy, until the holes plugged. Rust and mosquitoes were both breeding in there.
Well, my friend took a screwdriver and cleaned out the drain hole. Got all the water to drain through the drain hole, and splashed a bit more water in there to rinse things out. Worked that down through the drain hole too.
You know where this is going. About that time he noticed none of the water was coming out the bottom of the car. What he had done was, with the paper-thin rust prone steel AMC used, he had rubbed a hole through the top of the gas tank (which was under the station wagon's cargo floor) and had put all that rust and water right into the fuel. The name of Helen Blazes was invoked with great fervor.
What he should have done was pull the tank, get it cleaned out, and probably clean the fuel lines and replace the fuel filter while he was at it. But the car was an oil-burning rust bucket and wasn't worth the maintenance cost. So what he DID do was run about three gallons of gas line antifreeze through the thing.
It worked just fine. No problems.
My theory (which turns out to be correct) was that much of the water in your gas tank condenses out from the air. You always have some air in the gas tank. As temperature rises and falls the air expands and contracts, moving some old air out and some new air in. Moisture comes in with the new air, condenses out inside your tank, and there you are, water in the gas.
My friend Tom, who comes from a family that owns gas stations, told me you should never buy gasoline at a station that's receiving a shipment from a tanker truck.
"Because the gas station might explode?"
He laughed at me. "No. Well, actually, if it's ever going to explode it's more likely to when they're getting a shipment, but when does that ever happen?"
There isn't, or wasn't, a downtown Birch Run because the gas station went up while they were taking in a shipment one day, but I didn't mention that. "What's the reason, then?"
"There's always sand, grit, water. You know, miscellaneous crud. There's always some of that in the bottom of the gasoline tank. When they're filling the tank from a truck it stirs up all the crud. You fill up then, you get the stirred-up crud pumped right into your gas tank."
Makes sense to me.
Once you DO get water in your gas tank, you have to put alcohol in there to get rid of it. Maybe the best way is to buy a tank of gasohol, gasoline plus 10% ethanol. Ethanol mixes well with water (that's what vodka is, maybe 40% ethanol and 60% water) and it mixes with gasoline, so burning a tank or two of that will mix the water into your fuel and burn it out of the system a bit at a time.
Sometimes I add gas line antifreeze, which is alcohol too. There are two kinds they sell for that purpose. The slightly cheaper is methanol, wood alcohol. It will mix with the water and prevent it from freezing, which is good, but it doesn't mix well with gasoline, so it won't work the water out of the system. Isopropyl alcohol costs a bit more but will make that three way water/ gas/ alcohol mixture and get rid of the moisture once and for all, so I think it's better. They don't advertise which they're using very much, though. You have to read the fine print on the bottle most of the time.
The stuff works pretty well. Witness another story a friend told me, about this AMC Hornet wagon he drove once.
The Hornet had many delightful design features, including a full size spare tire (as they all were, then) that was mounted in a slanted well in the back, under the floor. I don't know why they did it that way, I don't know why AMC did anything they did. When water leaked into the back (and some water always leaks in) it would get into that well, as the lowest possible point. But that was OK. As with many things in cars, there are drain holes to get rid of any water that happened to accumulate in there.
Fine and dandy, until the holes plugged. Rust and mosquitoes were both breeding in there.
Well, my friend took a screwdriver and cleaned out the drain hole. Got all the water to drain through the drain hole, and splashed a bit more water in there to rinse things out. Worked that down through the drain hole too.
You know where this is going. About that time he noticed none of the water was coming out the bottom of the car. What he had done was, with the paper-thin rust prone steel AMC used, he had rubbed a hole through the top of the gas tank (which was under the station wagon's cargo floor) and had put all that rust and water right into the fuel. The name of Helen Blazes was invoked with great fervor.
What he should have done was pull the tank, get it cleaned out, and probably clean the fuel lines and replace the fuel filter while he was at it. But the car was an oil-burning rust bucket and wasn't worth the maintenance cost. So what he DID do was run about three gallons of gas line antifreeze through the thing.
It worked just fine. No problems.
