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new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Wed Jul 09, 2014 3:03 pm
by greliot
My Mac is a 2005 26M. It's time to replace the old Tempo low profile 12 gallon fuel tanks. The new West Marine 12's don't fit; neither do the 2011 Moeller 12 LPT's I just ordered from iBoat. The fuel caps on either are simply too high to allow the hinged seats to fully lower; it's a closer fit on the Moeller's than the West Marine's. I could take off the caps from the old Tempo tanks and almost use them with the Moeller's - I would have to sand down the vent on top a little bit, and the guards around it. But I'd rather find a new 12 gallon tank that fits properly under the 2005 26M cockpit seats.
Any ideas? thanks
Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Wed Jul 09, 2014 6:23 pm
by NiceAft
What was it that went wrong on the old tanks? I have those tanks on my 2005

.
Ray
Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Wed Jul 09, 2014 6:25 pm
by Don T
There are aftermarket replacement caps that are low profile.
Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Wed Jul 09, 2014 6:42 pm
by greliot
@Ray - 9 years of tropical Florida Keys sun has taken its toll. I went to replace the tank mounted male fuel fittings and the black plastic tank plates that the fittings screw into just sort of crumbled away as I unscrewed/removed the fitting. It actually just pulled out. That, and the red tank color on the bottom cockpit side corners of both tanks has bleached to white, and feels thin. I should have put sacrificial fabric covers over the cockpit side of the tanks years ago.
Thanks for the advice regarding aftermarket tank caps - I'll look into them. Any particular names? I know, the internet should provide the answers. I was just hoping someone else had dealt with this and found newer tanks that fit. I searched around the forums here and didn't find anything. Thanks.
Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Thu Jul 10, 2014 8:38 pm
by mastreb
I've been looking into flexible fuel bladders to improve range and keep weight down below, but there are 13 and 15 gallon fuel bladders that should work fine on a Mac. They deform to fit the space, and with a little modding to put tie straps on the lazarettes that would both hold the bladder in and hold the lazarette lid down, they should work just fine and perhaps increase capacity a gallon or two. They're a bit more expensive than the Moller tanks, but not by that much. And they don't need to be vented at all since they collapse as they're used, giving a visual indication of when you're running low.
Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Thu Jul 10, 2014 9:54 pm
by seahouse
As a general note about plastics exposed to the sun (I have no specific knowledge relating to gas tanks), fading of the colour can, but does not always indicate a failure or weakening of the plastic itself. There are cases where it is simply the colour additive that has broken down, and the parent plastic can still have retained a large part of its original strength. The colour red is specifically more susceptible to UV breakdown than some other colours.
Of course, on a gas tank you are going to throw away you can test it with a ball peen hammer on the faded vs the non-faded areas.
Since I have been dissapointed in the quality of the fittings used on my name-brand gas tanks (= leaks when brand new), it's not too far a stretch to believe that they also cut corners in the choice of materials used in their construction as well. ie insufficient UV inhibitor added, and dilution of material integrity by using higher than specified percentage of reground material in the mix.
- B.

Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Thu Jul 10, 2014 11:28 pm
by cptron
I have one tank that the plastic is breaking down so bad that the outside layers are coming off where it is exposed to the sun. It looks like me after being in the sun too long.

Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Thu Jul 10, 2014 11:58 pm
by seahouse
Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Fri Jul 11, 2014 1:13 am
by cptron
Not yet. Just waiting for it to fall apart. Like me again

Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Fri Jul 11, 2014 5:08 am
by RobertB
I installed a new Moeller on my

and had the same problem (it was a replacement from Moeller for a defective tank). I needed to use an old cap to make it fit.
I brought this up with Tattoo - they said they had no problem.
Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Fri Jul 11, 2014 8:34 am
by Andrew2012
Same Problem and funny enough same answer!
Will have to look for a replacement cap.
Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Sat Jul 12, 2014 12:59 pm
by Dimitri-2000X-Tampa
Yea, I have some 14-15 year old 6 gallon tanks that are all discolored by the sun like that..they are always exposed. But so far no leaks so I guess they are holding up...but sure are ugly!
Which makes me wonder...cause since I intalled my fuel filter in one of the lockers, that one probably won't take a 12 anymore not to mention that I like putting my propane tanks there too. But in the other side, I probably could install a 12 gallon and that way, my normal capacity could be 18. So has anyone put a 12 gallon tank into a

boat lately and could tell me what model fits without having to do any cutting?
Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Sat Jul 12, 2014 3:47 pm
by dlandersson
I must be missing something...when I replaced my "old" 6 gallon tanks, and found out the "new, improved" ones did not fit, I went out and bought some brand-new "old" ones.

Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Mon Jul 14, 2014 5:56 am
by Catigale
I got the nice snap on covers for mine which protects them from sun. Of course, in the spring, bald face hornets like to build nests in the nice and quiet space, so I open them carefully.
Re: new 12 gallon fuel tanks don't fit under cockpit seat
Posted: Mon Jul 14, 2014 7:10 am
by Sea Wind
Dimitri-2000X-Tampa wrote:Yea, I have some 14-15 year old 6 gallon tanks that are all discolored by the sun like that..they are always exposed. But so far no leaks so I guess they are holding up...but sure are ugly!
Which makes me wonder...cause since I intalled my fuel filter in one of the lockers, that one probably won't take a 12 anymore not to mention that I like putting my propane tanks there too. But in the other side, I probably could install a 12 gallon and that way, my normal capacity could be 18. So has anyone put a 12 gallon tank into a

boat lately and could tell me what model fits without having to do any cutting?
I bought the low profile 12 gallon moeller tank. I used the dremel on the lips of the fuel storage area to make it fit. I also added a 6 inch deck plate right over the cap to create the extra space. You don’t want to be moving it anyway because it is very heavy, so it is filled from the top only. Due to the tight fit, I always leave the pressure cap open in the summer.