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Last seen: 9 hours 28 min ago
Joined: 11/26/14
Posts: 10
Fuel tank internal access

Does anyone know if there is a removable inspeciton plate on the fuel tank for the C36 MKII, and if so what size is it? Need to polish my fuel.

Haro's picture
Last seen: 6 hours 22 min ago
Joined: 11/7/14
Posts: 256

Inside the port lazarette there is an access cover. After removing you will find the fuel sender mounted on a 2 inch plate that is fastened with screws. Remove screws to see the fuel inside.
This is the sender unit that I recplaced my sender unit with from Catalina direct for C36   part number Z3529

Siler Starum's picture
Siler Starum
Last seen: 3 days 16 hours ago
Joined: 4/20/18
Posts: 53

I believe you will have limited space to polish the tank from the top through the inspection cover in the PS-lazarette area. Maybe easier to remove the panel in the aft-cabin and slide the fuel tank out... (hope it is the same set-up as on our Catalina..)

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Durk Nijdam
Catalina 36MKII - 2001 / hullnr. 2013
Stavoren - Holland
Last seen: 11 hours 3 min ago
Joined: 6/15/17
Posts: 10

My husband Chris built a polishing system last year. It worked very well. He removed the sending unit on the top of the tank to gain access. He used a somewhat pliable metal hose to siphen the diesel out to run it, through fuel a water/fuel seperator first, then a set of dual racor fuel filters.. The whole operation ran off a 12V electric fuel pump that was connected (temporarily through jump cables) to the battery bank. 

We felt the key to getting as much gunk out of the tank as possible was to use the wand to aggitate the fuel, disturb the bottom and reach all crevices (as best as possible) with the wand itself while the operation was running. 

The opening WITHOUT the sending unit is approximately 1.5-2" in diameter, too small to access with your hand/arm.

The whole project cost about $120 and helped us to clean detritus out of our fuel until it ran clear. 

Hope this helps!

Cyndi Van Herpe
s/v Slip Away
1995 Catalina 36 Mk II
Hull 1443
Deltaville, Virginia
alfricke's picture
Last seen: 1 week 1 day ago
Joined: 4/14/09
Posts: 41

A few years back I polished the fuel on Jubilee...it was straightforward and easy. Just remove the round plate that houses the fuel guage sender unit. Polisher's intake hose goes in there, then the return is through the regular fuel filler. No problems. 

Al Fricke
S/V Jubilee
Catalina 36' MkII  #1867
Last seen: 1 month 6 days ago
Joined: 9/27/09
Posts: 480

I had a couple of fuel tank problems a few years ago and took the tank out to scrub it. If you don't have to I would not recommend removing it because  there are tabs on the forward end of the tank that screw down into the deck. The screws  have to be removd and there is about 1" of clearance for you to get your hand in there with a screw driver to make 1/8 turns.

The second time I took the tank out I gave up and installed an access port on the top of the tank. I got an 8" cover plate for the opening I cut into the tank (plastic) and a 10" access cover (from West Marine). I used this  in the starboard locker next to the fuel sender unit to cover the hole thru the deck in the locker I cut to access the hole in the tank. 

Now if I want to clean the tank I run the fuel down, pump out what's left with my oil extraction pump and I can get my hand and arm into the tank to scrub it with a Johnny Mop. I then flush it with a solvent such  as alcohol, remove that with the oil pump, and simply refill.


Chuck Parker
HelenRita 2072 Mk II
2002 Tall Rig - Winged Keel
Atlantic Highlands, NJ

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