Plastic Portable Tank Vent Question

[CharlesW]

How do most of you handle the vent open/closed issue when the boat is not going to be used for a while?<br />Tempo, six gallon tanks in particular is what I am concerned with.<br />Usually, I have just screwed the vent screw to the closed position when finished using the boat for a few days. Recently, I noticed that the sun must have expanded the fuel or the fuel vapors enough to really cause the tank to deform. It was very much pushed out on the flat areas. Releasing the pressure on the vent screw took care of the problem. Since then, I have left the vent open a small amount. That seems to be working OK. <br />Thoughts, comments?<br /><br />Charles

 

[tony_cliffy]

Re: Plastic Portable Tank Vent Question

Charles,<br /><br />Would you leave an opening to your gas tank on your boat while you stored it? I've used one of these tanks for many years and always closed it. At the end of the trip. Otherwise I found gas leaking/blowing out during the ride back home on the trailer. Also, I was always able to take my tank out of the boat and put it in a shed or garage so maybe you can't do this? Somehow you can't leave it out in the sun like that because gas will really attempt to expand. If you have to leave it at the boat then perhaps you can place it in the shade under the boat or possibly build a little white box to put over it or somehow shield it?

 

[cjones4@hvc.rr.com]

Re: Plastic Portable Tank Vent Question

I use these tanks also and have found it best to leave the vent just slightly opened when in use and in storage. Close it tight then back off about a quarter turn. The only time I shut it tight is when transporting them in the car.

 

[CharlesW]

Re: Plastic Portable Tank Vent Question

tony cliffy: "Would you leave an opening to your gas tank on your boat while you stored it?"<br />Actually, I think I do. The vent is alway open, (I think), on my Chris Craft I/O, and I'm pretty sure it was on my Slick Craft I/O as well.<br />These tanks are on a pontoon boat and my concern is basically when the boat is tied up at the dock. The only reason I closed the vents was to be sure I didn't get water in the tanks from rain or waves splashing over the tanks.<br /><br />mooner: The close and then open 1/4 turn method is what I have been doing in recent weeks. So far, I don't seem to have any problem with water getting into the tanks.<br /><br />Charles

 

[quantumleap]

Re: Plastic Portable Tank Vent Question

The more air that is allowed to get in the tank, the more condensation that forms on the inside and ends up in the fuel.

 

[KCLOST]

Re: Plastic Portable Tank Vent Question

Metal tanks exposed to sunlight and open air are really suseptable to condensation.. So it's best to shut those vents whenever possible to keep the environment within the tank as normal as possible, thus reducing condensation as Quantum mentioned. Try to cover them up in some way to prevent drastic temperature variations...<br /><br />However, my on-board tanks (and most all that I'm aware of) always have an open vent. So if the temp. doesn't variate so much, it's probably not going to hurt. But my tanks are plastic also and totally covered within the hull.

 

[rochester]

Re: Plastic Portable Tank Vent Question

I also have the ventless OMC plastic tanks. Two of them. They expand and contract quite a bit, depending on temperature so I leave them cracked in my garage. I guess that means that I am releasing gasoline vapors into my garage. However, if I had a vented built-in tank, I would be doing the same thing if I stored my boat in my garage, wouldn't I? One thing I have noticed is that a full OMC plastic tank seems to be significantly less affected than a nearly empty tank. Maybe I should just fill the tank(s) when I get home? I bought them because the steel tanks I had were leaking from this pressure build-up around the hose connection fitting, and it seemed they were perpetually coated in a gasoline film even when in the boat. The plastic tanks are bone-dry when in the boat and underway. I was concerned about this expansion and contraction before I bought the tanks, but I called Bombardier and asked about it and they said not to worry about it... so I ain't. <smile)