Fuel tank confusion...

May 23, 2016
1,024
Catalina 22 #12502 BSC
Time to replace the original 3 gal merc metal tank w/a 6 gal. capacity for more range. I see all these are EPA approved NON VENTED "Low Permeation" tanks, many reviews are lousy, especially if left in the sun, "tank leaks, blows up (expands) like a balloon" etc., etc.

here's an example: https://www.westmarine.com/buy/west...on-above-deck-fuel-tank--13854211?recordNum=3

So what's the deal and what to buy? Boat is an '84 so the port side aft laz fuel tank space has not been used based on the many comments of fumes leaking into the cabin space (I've kept it in the cockpit at transom). That said, if a non-vented tank actually works (and it must somehow), maybe it CAN go the laz space and not leak fumes, yet they are listed as "above deck"!??

Confused on this one, thoughts, comments, recommendations?
Ron
 
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Sep 15, 2016
790
Catalina 22 Minnesota
Non vented could be an issue. I have a new design and so I have the benefit of the fuel tank locker being sealed from the cabin. However one time last summer I forgot to open the vent on the tank and I had fuel everywhere. Even covered in the locker the tank warmed and expanded pressuring the tank. This caused the fuel to push out of the o-ring on the motor fitting while it was disconnected making quite the mess. If this was in the cabin space / bilge it would have been a nightmare.

If you have to go ventless then get a cheaper one, try it, and if there are issues drill a vent hole in the top of the tank and thread it to fit a plug when you need it sealed. The EPA has made a mess of all this. I can't even stand these new jerry cans that have spring loaded pour spouts etc...
 

AaronD

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Aug 10, 2014
723
Catalina 22 9874 Newberg, OR / Olympia, WA
I had the same problems everyone else reports with the new tank style. I eventually replaced the cap on mine with a vented one like this: https://www.westmarine.com/buy/moeller--low-profile-manually-vented-fuel-cap--13099544?recordNum=3 (Our SBO hosts might carry one too, but I didn't find it in a quick search). I open the vent when it's warm and close or cover it when it's raining to avoid getting water in the fuel (my tank is lashed in the cockpit, so exposed to rain; the vent shouldn't leak easily, but just in case).
 
Sep 30, 2013
3,538
1988 Catalina 22 North Florida
That cap wouldn't fit the threads on my expando-matic fuel tank. I finally took matters into my own hands and MADE my tank vent.

The whole thing makes me want to choke some EPA Nazi til he turns purple.
 
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Mar 26, 2011
3,400
Corsair F-24 MK I Deale, MD
a. You really want to close the vent when you are not sailing to prevent water absorption and reduce evaporation. You want to reduce evaporation, not because the EPA said so, but because the most volatile part helps with starting! So in effect, all portable tanks should be non-vented. (Installed tanks are well served by silica gel vent filters.)https://sail-delmarva.blogspot.com/2012/11/gasoline-and-fuel-tank-vent-filters.html
b. If you don't close the vent there is a high probability some rain will splash in.
c. The reason the tanks pressurize more is that E10 has a greater vapor pressure than traditional gasoline. It is not the tank, it is the fuel that changed.
d. Get the tank out of the sun, even if this just means a canvas cover. It will be much better for the tank, in terms of UV, heating, and rainwater.

I don't think this is an EPA issue so much as a good design issue. E10 is an agribusiness product that the EPA is not really very fond of and never was. Place the blame on agribusiness, where it belongs. And no politician will take on agribusiness, in either party, because it controls critical swing votes and because the man on the street does not understand the trick that has been played on them.

 
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Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
Look at the new Moeller portable tanks. You want a Kelch-type cap which has a manual vent and auto 5 psi vent. But like thinwater says it is essential to seal your tank when not in use, otherwise your fuel will absorb moisture and your carb problems begin.

NEVER leave the fuel hose attached to the tank when not in use. The tank top fitting is designed to hold pressure, your fuel hose motor side fitting is not so robust. Even leaving it attached to the motor in the hot sun risks filling your outboard crankcase with fuel.
 
Feb 6, 1998
11,665
Canadian Sailcraft 36T Casco Bay, ME
The tank top fitting is designed to hold pressure
:banghead::banghead::banghead: "Designed to" and "DO" are entirely different realities. These tanks, every brand I have come across, leak like sieves from the tank fittings when they blow up like a balloon.

There is hardly day that goes by in the summer where I don't go by a self bailing boat, with portable fuel tanks, that does not have a fuel sheen ring around it.

I have written no less than 20 letters to my State and Federal representatives and no one gives two $hits about this MAJOR issue......

The big issue here is that you need a tank designed for below deck use eg: permanently installed.. Portable tanks are not for below deck use regardless of the way they vent..
 
May 23, 2016
1,024
Catalina 22 #12502 BSC
Yikes, what a can-o-worms......my old 3gal merc tank is still serviceable...after all this great commentary, I'm really inclined to continue with it and carry a supplement 3 gal can (the one used for the leaf blower/weedwhacker) for longer journeys....apparently there is no good RELIABLE turnkey option out there!!!
 

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
:banghead::banghead::banghead: "Designed to" and "DO" are entirely different realities. These tanks, every brand I have come across, leak like sieves from the tank fittings when they blow up like a balloon.
The Moeller portable tanks now ship with the Kelch pressure-release cap, it auto releases above 5 psi. If your tank fittings can’t hold 5 psi you have a fitting problem. Fuel is different than it used to be, it has tremendous vapor pressure, trying to use an old tank with current fuel is a problem. The last tank I purchased the tank fittings were not permanently installed and required the application of thread sealant. That was surprising. I don’t know if the Kelch cap is available for retrofit, but it works the way fuel caps used to work, allowing manual venting, and preventing the tank hogging effect. The auto vent is the trick.
 
Jun 21, 2011
49
Catalina 22 MKII Scarborough, Ontario
How does this affect smaller outboard motors with built in fuel tanks?
I purchased a new Mercury 5 hp Sailpro motor last year and have been using the internal fuel tank without any noticeable problems. I have a separate external tank, but have found using the internal tank more convenient. I always carry a small portable fuel tank, just in case I need to refill the internal tank. Seems to work well!
 
Apr 26, 2010
434
catalina 22 lake tillery NC
My first Non vented tank didn’t last one season. The second tank I bought from bass pro and the self venting cap has worked for 2 years now I have no fumes inside my boat they must go right out the vents in my hull
 
Jul 26, 2016
94
American Sail 18 MDR
Plastic approved tanks stink of gasoline and the essence permeates enough to make you sick of the smell. If you get a plastic tank you need to vent it with a line lead outside the cabin or locker. I have had my issues with them. I only buy the metal gas cans. They do not permit the "essence" to pass through when closed.

Plastic tanks are a problem in center console powerboats because the tanks are stored below deck in an enclosed foamed it compartment. Yet they make the bilge stink of fresh gasoline. In many cases the smell permeates all enclosed spaces.

I have 136 gals of ethanol gas in the aluminum tank that replaced the plastic "EPA Approve low permeation fuel tank" Have had no issues with ethanol since I converted to Aluminunum tank in 2002.

I have a white cover to keep the dinghy plastic fuel tank from heating up like a puffer fish.
 
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Sep 8, 2014
2,551
Catalina 22 Swing Keel San Diego
I just stick with a 3 gal tank that fits perfectly on the cockpit sole just under the tiller. It doesn't take up any space that is really useable since I doubt anyone would ever sit in such a way that their legs and feet would be under the tiller. For extended range, I just have a second tank. Haven't figured out where to store it just yet. Worst case, I will build a physical divider to isolate the 'fuel' locker. I have CNC router on the way to deliver in June, would be a perfect project to test it out by cutting some plywood panels to create their divider.
 
Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
I have also had a lot of frustration with the new "improved" gas cans. Just like Maine Sail said, all of mine have leaked much worse than their supposedly inferior predecessors.

For now, I have gotten around the problems on Jerry cans by making my own storage plugs & self venting pour spouts with O-ring seals. They don't leak a drop. The spouts give good flow rates & are easy to get into filler necks. The plugs are air tight & keep the moisture out of my fuel. The O-rings need to be made of Viton for gasoline & Neoprene for diesel.

When my outboard croaked in heavy seas from fuel tank suction with a new tank, I cracked the cap open, pumped the bulb, & got going again, but I should not have had to do that. Being in a small boat with a dead outboard in heavy seas is a very dangerous position to be in. I was put in that position by these new "improved" systems.

These new tanks can & do cause a lot of harm. I am hoping that the manufacturers get their heads out of whatever dark places they are now in, & manage to start producing something that actually works, sometime soon. Until then, I am stuck with DIY solutions for the problems that they created. I have better things to do with my time than designing & manufacturing things that I should be able to just buy for a reasonable price. If this keeps going on, the words "class action" may have to come into play.
 

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Apr 1, 2016
21
Catalina 22 14735 Lake St Clair, MI
Related dummy question. So, on a new style boat with the 6 gal tank in the port locker, how should everything be set when boat is sitting at the dock not in use? Fuel line disconnected from outboard? Fuel vent on cap open or closed?
 
Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
I leave my vents closed for extended storage, assuming that the tank was designed to handle that kind of pressure build up.
 
Jun 9, 2004
615
Catalina 385 Marquette. Mi
You will HATE the treehugger fuel tanks. They are awful. Run as quickly as you can. Many old style nos on eBay