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Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Fri Mar 16, 2018 6:29 pm
by BeaconMarineBob
Here are some pictures and information on the installation of two Moeller 58 gal fuel tanks installed in a 1977 F-32 model 321.

Fuel Tanks are made of Polythylene

There tanks replaced the aft original galvanized round tanks.

Tanks are 44” long by 21.50” wide by 18.75” high

We have some good pricing and shipping cost on these tanks
* For a F-36 Moeller makes a 126 gal tank like the picture above.
54" Long by 32" Wide by 21.25"

** High add 2-1/8" to tank height to accommodate fill height

Re: Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Wed Sep 19, 2018 10:06 pm
by TADTOOMUCH
How did you disconnect fuel filler pipes to get tanks out? I’m replacing my tanks in 3 weeks

Re: Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Thu Sep 20, 2018 7:12 am
by BeaconMarineBob
With two very big pipe wrench’s

Note the fuel fill is 1 7/8” and new Plastic tank is 1 1/2” hose.

You need to remove fill and weld a reducer on the fill to bring it down to 1 1/2.

Note: you need to provide a new ground to the fuel fill.

Feel free to call
Beacon Marine
609 713 4602

Re: Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Thu Sep 20, 2018 8:26 am
by mikeandanne
If you have the original deck fills, remove them from the boat, they come apart and you can screw a new correct fitting to it to fit the fill hose......access to the fuel fill hose connections is behind the aft panel in the side sliding storage areas.It is quite easy really, just cut the hose that joins the deck fitting to the pipe , also a ground strap is there.That is how our 78 was, did the same job.

Re: Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Wed Oct 17, 2018 8:57 pm
by TADTOOMUCH
I got the old tanks out. Really quite easy. Should have done this ten years ago. My tanks are Moeller 64 gallon with tapered bottom sides with a flat bottom. Got a great deal on them ($500 for both) because our marina mechanic ordered them for another boat but got dimensions wrong so bonus for me! Will need to modify the round saddles with a flat piece of marine plywood and some straight pieces screwed to the old round saddles. Is the 1-1/2” fuel hose flexible enough to connect straight to the deck fill and to the tank without any elbows like the old tanks had? Can I just connect a ground wire from deck fill down to the tank connection instead of a copper strap like the old tank had? Then connect a ground wire from the tank fill connection to the boat grounding system? Thanks for any help

Re: Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Wed Oct 17, 2018 9:18 pm
by prowlersfish
the hose should flex enough , avoid dips/low spots . Wire will be fine for grounding .

Re: Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Thu Oct 18, 2018 10:33 am
by mikeandanne
Your tanks may be different , but on mine the hose pulled sideways on the plastic tank inlet fitting, so ran the hose thru the bulk head to get the drop right, with the appropriate chafe guarding of course, the only joint you really want is at the deck fitting and at the tank itself. After you run the ground from the tank to the deck fitting, double check your connections to ground with a multi meter as you dont want any kabooms.

Re: Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Fri Oct 19, 2018 2:58 pm
by TADTOOMUCH
I am thinking about replacing the fuel tank vent fitting in the side of the hull. Anyone do this and what did you replace yours with. Mine are looking sort of cruddy and don't want this to be and issue after I just replaced the tanks. What did you hold your tanks in place with? Did you use any foam or neoprene pads on the straps holding the tank in place? I read that you need to allow for tank expansion.

Re: Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Fri Oct 19, 2018 8:51 pm
by P-Dogg
I didnt do fuel, but i did water. Bought a stainless steel strapping kit to hold tank in place, because everyone needs one, right? Big honking (thats the technical term in latin) band clamps would prolly work as well. Remember, you can join them end to end to build length. Used plastic corner protectors available in the strapping supplies section of the man's toy store: www.mcmaster.com

See pics of install here: http://www.trojanboats.net/wforum/viewt ... ank#p82312

Re: Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Fri Oct 19, 2018 9:01 pm
by P-Dogg
And as for expansion, i relied on my straps being half an inch wide and 0.040" thick, and my tank being 5' long. Straps may stretch tighter and deform elastically, and tank may get squeezed a tad locally, but overall prolly not an issue unless the whole tank us restrained.

That said, my tank is not subject to wide temperature swings, which might be the case if tank was in engine compartment. You could always find coefficient of thermal expansion of the tank material, and multiply that by the temp swing and length and see what kind of actual dimension changes you could expect and thus plan accordingly.

Re: Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Sat Oct 20, 2018 8:51 am
by mikeandanne
Its the fuel that makes the tank swell ( expand ) FYI, it does pretty much what the instructions say.I left a space around the bottom shelf it sits on and , a few small adjustments, the hard part was getting at the hold down fasteners as we had the waste tank, air conditioner etc all in the middle.

Re: Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Fri Oct 26, 2018 1:37 pm
by TADTOOMUCH
So I am doing the grounding wire from the deck fill to the tank. The connections at the tank are plastic so do I run the wire all the way to the sender or just make the ground connection to the old ground wire that was connected to the round tanks or both? I assume I will check for continuity to ground with a multimeter.

Re: Plastic Fuel Tanks installed in a 1977 F-32 model 321

Posted: Fri Oct 26, 2018 1:44 pm
by TADTOOMUCH
I'm making the ground connection to my deck fill with new 1-1/2" hose barb fitting and both the fill and vent connections on my tank are plastic. So do I run the ground wire to the sender unit ground or to the old round tank ground wire or both so that I have a good ground. I will be checking ground continuity with my multi-meter.