# Plastic 6 gal tank trouble



## Sr.Jigger (Feb 17, 2005)

I bought this plastic tank at Cabelas with a new hose. This tank swells up like a football with pressure all the time. I see no relief valve but the cap has a automatic vacuum control system.

It's the swelling up and pressure that's the problem. It's made by Attwood and about $50.00 bucks. This is the only brand they sell. Anyone else have this problem. Seems like the tank cap should work both ways (vacuum control or pressure control). Did I get a bad tank ?


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## Salmonid (Apr 14, 2004)

is there a twist release valve on the top of the screw on cap?? how about a pic, that might help many of the atwood s have the cap and in the center of that is a twist nozzle for the vent, does that make sense?? 

Salmonid


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## sherman51 (Apr 12, 2011)

I think its normal for the tank to swell up. I have 2 6 gal tanks in my boat with the vent valve in the center of the cap. I keep these valves closed except when im using them, and they do swell. it just keeps the gas from evaporating and having gas fumes from gathering in the bottom of your boat.

I could be wrong about this but I have always stored my tanks with the valve closed. you should get more guys chime in on this one.
Sherman

I looked at the tank at cabelas and there doesn't seem to be a vent valve. so it must have a 1 way valve built into the cap.


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## crappiedude (Mar 12, 2006)

Salmonid said:


> is there a twist release valve on the top of the screw on cap?? how about a pic, that might help many of the atwood s have the cap and in the center of that is a twist nozzle for the vent, does that make sense??
> 
> Salmonid


Yep...what he said. Open that screw cap and let the pressure out. I used to leave mine open all the time.


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## Fishingisfun (Jul 19, 2012)

Sr.Jigger said:


> I bought this plastic tank at Cabelas with a new hose. This tank swells up like a football with pressure all the time. I see no relief valve but the cap has a automatic vacuum control system.
> 
> It's the swelling up and pressure that's the problem. It's made by Attwood and about $50.00 bucks. This is the only brand they sell. Anyone else have this problem. Seems like the tank cap should work both ways (vacuum control or pressure control). Did I get a bad tank ?


I checked my two plastic tanks and both have air valves in the center of the gas cap. All black plastic cap with four upright tabs the smaller center is a twist valve that alows air into the tank so fuel flows freely. Right tight closed, left is loosen to open and allow air in. I leave valve open while running the motor and when stored so it does not swell up and only close the air valve when hauling the boat down the highway to keep fuel from sloshing out the air valve. 
I had a square plastic gas can swell up to where it was round when I discovered I had left the valve closed. Always opened them after that for storage.


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## sherman51 (Apr 12, 2011)

crappiedude said:


> Yep...what he said. Open that screw cap and let the pressure out. I used to leave mine open all the time.


I went to cabelas web site and enlarged the picture and then zoomed in on the lid. it doesn't look to have the normal screw vent on the lid. check it out at cabelas.com.
sherman


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## Fishingisfun (Jul 19, 2012)

Sherman your right, I looked and I cannot see a vent on the Atwood tank. It would seem they have not vented the tank. It seems like a problem in the design to me.


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## whjr15 (Jun 16, 2005)

I have one of those tanks as well, and they definitely don't have any venting caps/valves/screws etc.

Not sure if it's a bad thing, but it's never affected anything. I just don't like the thought of having a pressurized plastic tank! Sometimes the thing will inflate so much that it no longer has the indentation around the cap area, and really does look football-shaped!!

Have only had it a little over a year, and only use it when I take my smaller boat out (which isn't much) so I never really gave it a second thought! It is very strange looking though!


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## Gottagofishn (Nov 18, 2009)

An unvented tank sounds kinda scary to me. What about disconnecting the fuel line from the motor? Wouldn't that pressure make for a mess?


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## thebear (Apr 24, 2014)

This is a VERY common complaint with Atwood products, look them up on amazon.

I have a 6gal kicker tank by them and ended up buying a different cap for mine; atwood does not sell them with vented caps.

Kicker shut off one time trolling into the waves because the cap didn't vent and the pressure built a vacuum and the motor didnt get any fuel. I picked up a vented cap from west marine for like 13 bucks


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## I Fish (Sep 24, 2008)

This isn't political, as this is the reason:

Pursuant to Section 213 of the Clean Air Act;
40 CFR 1060;
1060.103 Permeation emission control requirements for fuel tanks;
1060.105 Diurnal requirements for equipment: Caps

In other words, thank your EPA. No fuel tanks can be made with a free flowing vent. They have to hold back vapor pressure until 5.5 psi. I fully expect them to start with an expiration date just like any other gas bottles, like oxygen or acetylene. After so many years of use, that plastic has to break down and get weak.


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## bludog (Apr 15, 2011)

I had the same problem with atwood found a vent cap at gander that fit perfect I believe it was made by moen or something like that.


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## Fishman2025 (Aug 14, 2009)

Its not just attwood. It is a new regulation. 

Even new boats have a bladder in the tank to do the same thing.


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## sherman51 (Apr 12, 2011)

if you really want a vented tank go to ebay and see what they have. they have them from about 45.00 to 59.00. problem solved. just type in 6 gallon boat gas tank. and 6 gallon fuel tank. and 6 gallon marine tank. you'll find all you want to look at. be careful and don't buy one that says epa compliant.
sherman


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## turkey hunter (Jan 4, 2015)

i have one of those attwood tanks with the same problem so I just drill a small hole in the center of the cap and put a small screw in it when I use that tank I just take the screw out it works just fine.


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## buckeyebowman (Feb 24, 2012)

I Fish said:


> This isn't political, as this is the reason:
> 
> Pursuant to Section 213 of the Clean Air Act;
> 40 CFR 1060;
> ...





Fishman2025 said:


> Its not just attwood. It is a new regulation.
> 
> Even new boats have a bladder in the tank to do the same thing.


Exactly! It's the same reason you can't buy a gas can, like for your lawnmower, with the simple pop open valve to keep air from "glugging" up through the spout when you're pouring fuel.


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## kendil (Mar 24, 2015)

It seems so. We recommend that you make a complaint. It seems to me.


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## I Fish (Sep 24, 2008)

kendil said:


> It seems so. We recommend that you make a complaint. It seems to me.


Good luck with that.


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## Sr.Jigger (Feb 17, 2005)

The thing is, once you have a tank that's swelled up full of pressure it's a problem and creates a good chance of gas spill and leaking. Mine leaked gas around the motor hose connection, down through the motor casing and on to the floor. Making a mess and a hazard for fire. So the new tank/caps fixed one problem and caused another. End of story.


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