Hi i was wonder if i only used the aux fuel tank since i mainly do short trips what are the issues and chances with water getting into the main thank. I plan on using a fuel stabilizer and water separator. I want to shift the weight towards the bow as much as possible so i plan on mainly using the aux tank. What do you guys recommend i do?
grady 228 aux fuel tank
- Thread starter ba_reefer
- Start date
There is in theory no issues running that tank empty. The problem is that is is just about impossible to get it empty with normal use. My suggestion is to put in some gas and stabilizer every now and then and run off that tank long enough to use up about half of what was in it. For example add 10 gallons and some stabilizer and then use up about half. You can leave the stabilized fuel sit for a lot longer than you may be led to believe , six months, even a year. Of course you will hear all kinds of stories about condensation in an empty or almost empty tank. I and most of the other boaters at my club, store their boats with a lot less than full tanks and every issue with water last season has been traced to water intrusion via the fill, vent or sender plumbing. As a matter of fact, we have boats that have had partially full tanks that sat for years and were able to use the gas in them. We kind of judge by smell. Really bad gas smells really badba_reefer said:
The trick to using old gas is to dilute it with new fuel. We have folks who love to hear people say, " I have old gas in my tank, how can I get rid of it?". The answer,"I'll take it. For older less high tech motors and out yard equipment, older carbed trucks, power washers, etc. using oldish gas has not been an issue. Would I take a chance on 3 year old gas in my boat? NO but gas that sat in my tank for 6 months, no problem.Depending on the size of the tank and the humidity and temperature swings in your area, condensation can make a lot of water in a big empty tank. Water can be both an engine and a tank corrosion problem if condensation is high. Water-in-the-fuel warning systems on some engines work great in alerting you to problems, but without that, once you fill the water separator, all kinds of expensive engine problems can occur. Would not be an issue in Arizona. It's a big issue in west central Florida.
Boy would I like to see some real scientific research on the condensation discussion. Yes, I agree that weather conditions in Florida are different than the northeast but I still feel the risk is overstated. As to winter storage and condensation, the problem just isn't dire as many state in my area since the winter temps are cool to cold and the air is usually pretty dry.wspitler said:
The argument that alcohol fuels make matters worse is misleading in a way since ethanol fuels can actually absorb a certain amount of water (about 1/2% by volume) whereas ethanol free gas can not and that 1/2% if present sinks to the bottom. ( 9 out of 10 times when a owner in our yard thinks they have a condensation issue, I ask if they have looked at the o-ring on their gas filler cap. You would be surprised how many have found that they didn't even have an o-ring (but should have)
You point about possible corrosion is valid and that can be an issue. My recommendations are to add new gas fairly frequently during the boating season and in the spring ( in the north east) don't rush to be first boat gassing up at the local marine gas dock. Often that gas has sat in their tank all winter.
thanks for all your help I'm here in california so i would think its a little better here. i appreciate all the help
seasick, you can see condensation science on a poorly insulated window of a house. Maybe even observe rotted wood around old windows from that same condensation. I'm not beating you up or trying to argue but it does happen inside tanks and should be considered to avoid phase separation of ethanol blends. Yes, E10 does like water....but enough of it and the nightmares of phase separation can begin. I lost 3 yard equipment carburetors and a 30 year old chainsaw to the stuff about 4-5 years ago so the bitter taste is still there.
I now use E10 because the non-ethanol stuff is just too expensive (35-40% more) to use. But I keep the fuel fresh, only buy from the same busy station and change filters way more often than required to keep an eye on what's going through the system.
I now use E10 because the non-ethanol stuff is just too expensive (35-40% more) to use. But I keep the fuel fresh, only buy from the same busy station and change filters way more often than required to keep an eye on what's going through the system.
I too have seen yard equipment carbs ruined by bad gas, perhaps it was water, maybe is was just old gas. The reality is that if you calculate how much water can condense inside a tank vented to the atmosphere, even with enormous temp swings and high humidity, the amount of water is relatively small. yes, the cycle will repeat and that can add more moisture but a boat tank and a carb can't be compared to a window that is quite warm on one side and not only cold on the other, but exposed to quite a large supply of moist air.GulfSea said:
You also need to admit that the moisture in the air in a tank can also be pulled out by the addition of drier air. The cycle works both ways.(Granted, water that is absorbed by the ethanol is permanent)
For phase separation, you need a lot of water by volume to gas.
I suspect that for whatever reason, small containers of gas go sour faster than larger ones. That may explain why we see issues with yard motors more that I have seen with boat tanks. The key here is TANKS. I do drain filters and fuel reservoirs during long storage and many owners at my facility will 'winterize' carbs by draining the gas and filling the bowl with Marvel Mystery oil. That serves too purposes; it reduces corrosion from moisture and for older machines, it helps protect the gaskets from drying out.
My point is that I have experience with over 50 vessels at my club and we just don't see a lot of condensation issues with partiality filled tanks over the winter. Most owners do not top off their tanks before storage and I don't recommend they do. The reason is simple: Should something go bad like a water intrusion issue, come spring they have to get rid of a lot of fuel that cost a lot to buy AND they have to pay for the proper and legal disposal of the gas and that cost dearly.
Just my two cents.
i believe the best way to reduce "condensation" and "bad gas" in boat fuel tanks is to replace the o-ring on the fuel filler cap regularly.
suzukidave said:
This and seasick's confirmation illustrates some misconception on ethanol fuel problems. Air gets in (and out) continuously through the vent line, not the fuel cap although they also have a very small vent as well. My yard equipment was damaged by phase separated ethanol fuel; my boat would have been damaged also but at the time I was only using non-e in it. What many also miss is that ethanol is corn, corn as any other food has a shelf life. If corn were in a store, we wouldn't buy it if it looked bad or if it was packaged with an expired date on the package. But when we buy it at the pump, there is no expiration date....which is why I will only buy from busy sellers, in hopes the fuel is fresh. It's not a guarantee but is the best that can be done since they don't date fuel.
Also, I never say "water will" accumulate due to condensation but that "it can." Give the right circumstances it can absolutely occur within a tank. Put a bilge heater in one of those boats with the right circumstances and the process is set up. Or maybe the right mix of temperature swings and the area a boat is parked in (sun exposure) could set up the process. I suspect this is why so many people swear both ways not really understanding why it did or didn't happen with their own boat.