Gas Tank Condensation

[dodge55]

Good Morning All,

Following up on the other gas tank question, how do I avoid condensation in my 37 gas tank? I had a few pin holes in the bottom, so I pulled the tank and soldered them. But when I pulled the gas tank sending unit (to help vent the fumes, which I did for about a week before putting a flame to the tank) I noticed an oval shaped rust spot in the bottom of the tank (about the size of a small hoagie roll). The rest of the tank was good. Since water is heavier than gas, does the condensation pool at the bottom of the tank causing the rust, even with gas in the tank? Is there a product that eliminates the water? How about gas tank sealers? Other than the fixed pin holes, tank is in great shape. Thanks.

Steve V

[nearchoclatetown]

Yes, water will pool and rust with gas in the tank. Rubbing alcohol will get rid of the water, poar some in with the gas. The old rule was keep the tank full. The recommendation with the "new" gas is empty the tank if the car is going to sit. The new junk eats things like aluminum and rubber. I personally don't like sealer, keep the tank rust free and you don't need to seal it. They weren't sealed from the factory. And that is JUST MY OPINION.

[Guest imported_woodwheels]

Steve: I am glad you are sill alive, flame to a gas tank that has sat dry for months is a dangerous proposition. Near chocolate is correct with his feelings about tank sealers. New gas is unstable, nasty stuff that will eat the stink off of skunk hair. Modern gas, with stabalizer, is good for no more than 4 months. Chain saws, mowers or cars all suffer and fail with modern old gas.

Condensation, in the gas, is a lesser issue with the newer plastic tanks. The colder the climate the more the problem. Older metal tanks lent themselves to condensation because of their thin construction. Once the tank is rusted, it is junk. You will spend more $, in the long run, gooing it and servicing your fuel system from the broken down goo than you will if you find a good sheet metal shop and have them fabricate a stainless tank, to match the old one. Paint it black and no one will ever know the difference, you will increase the value of your machine and deliver it clean gas and there by the dependability it is capable of delivering.

[Guest DodgeKCL]

Indeed you are very lucky! Even months after sitting with the cap off a tank will still go 'pop' when a flame is put inside it. The explosion usually rips the tank open along it's seams. The usual thing is to hook up the exhaust from a car/truck and feed it into the tank while you work on it. Obviously this is an outside in the fresh air job. The flooding CO purges any O2 and prevents any explosion.

Nearchoclatetown is right with the alcohol but it might be easier if you just use 'Gas Line Antifreeze'. This is alcohol for winter climes to stop the condensation in the gas tank/line from freezing in the cold nights. I think, but I'm not sure, that because all the gas has up to 10% alcohol in it now that putting alcohol in the gas may be redundant. However a little more can't hurt as it just mixes with the water and the water 'burns',it doesn't sit in one place on the bottom of the tank.

As far as I'm aware all the Chryco tanks had drain plugs on them. Is there not a small brass threaded plug in the bottom centre of your tank? It has, if my memory holds up, a 7/16" square head on it. I take mine out every once in a while and drain the bottom of the tank. I usually don't find anything because,I think, of the alcohol in our gas. Whatever I take out I use it in the garden tractor or chain saw rather than waste it. Never have seen water.

Our gas in Canada is 'seasoned'. Additives are put in for the winter and removed for the summer. I notice the US members have more discussions about 'stale' gas. I don't think we have such a problem in Canada. I've left gas in a motorcycle for several years and it started right up. Same with our snowmobiles. We just shut them off in March/April and put them away. Hit the starter in Nov./Dec. and they start right up. My chain saw has not been used since Sept. and won't be used again until May/June. But I know it will start with a couple of pulls with last years gas. I just put my antique cars away the same and they will start 6/7 months later on 'old' gas just as if they were shut down 2 minutes ago.

Maybe a stabilizer is put in by the Canadian gas manufacturers that the US outfits don't. I know the gas has to be very light, highly aromatic, for winter starting. The winter weather up here may force the gas pumps to put out a better fuel than the US gets because of the temperature extremes.

Anybody out there from North Dakota or Minnesota? Any of the northern states? You people have 'stale' gas problems?

[RickBrinker]

I live in Ohio and have had cars sit for 2yr with out starting them and have had no problems with gas one car sat for three years before I could get it out and the gas was starting to turn to varnish.thats the problem with having to many cars.

[Jan Arnett]

When I purchased by 23 screenside the vac tank would not draw gas. Turns out the line going into the tank had pin holes in it where it sat in the gas at a half full level. There were pin holes at the same level on the tank ends caused by all the condensation building up and allowing rust to form. It must have had several quarts of water in it at one time to rust where it did.