Fuel tank pump out

[manorden]

I recently purchased a 1984 55ft Convertible. It had been seized by a bank and the previous owner had let it sit for a number of years so it is in pretty bad shape. There was a good bit of water and slop pumped into the fuel tanks prior to me getting it. So my question is what is the best way to pump out the fuel tank before I treat it for algae? I've thought about going in through the hole where you would fill up but am concerned I would not get to the bottom of the tank this way. Any input is appreciated.

[Pascal]

Don't know what the tank set up is on that boat. On my 53 MY with keel tanks I recently had a fuel
Polisher pump what was left and clean the tanks. They used the 2" gauge hole

[racclarkson@gmail.com]

55Cs of that vintage have a good sized main tank flange just under the cockpit access panel. The forward tank has decent access in the ER, but a smaller flange to work through. So if you're needing to get in there to clean, be prepared for the screws holding the flange to disintegrate. I've replaced them at the main tank with SS bolts. So, there's likely going to be a bit more labor than you anticipated getting it all back together if simple polishing won't cut it. The main tank bottom is 34" deep from the top of the flange, BTW. The pick-ups are in an approx. 1-1/2" sump straight down. I use a dipstick (1/8" dowel rod) with graduations to double check the mechanical gauge anytime I'm running below a half tank on the gauge. When my gauge reads below 1/4 tank you be need'n to swap tanks---if you're running clean fuel. Hope this was helpful to you.

[Cricket]

Besides getting rid of the fuel you're probably going to have to clean the tanks while they're empty and then suck that stuff out too.

[dottieshusband]

I recently purchased a 1984 55ft Convertible. It had been seized by a bank and the previous owner had let it sit for a number of years so it is in pretty bad shape. There was a good bit of water and slop pumped into the fuel tanks prior to me getting it. So my question is what is the best way to pump out the fuel tank before I treat it for algae? I've thought about going in through the hole where you would fill up but am concerned I would not get to the bottom of the tank this way. Any input is appreciated.

Is fuel polishing not possible? Sounds like your saying stuff other than fuel was intentionally pumped into the tank? My boat also a bank repo...had sat for a few years, but although several years old, the 800 gallons of fuel onboard polished up just fine.

[Briankinley2004]

My 55c sat for a few years as well. No water issues though. I searched and talked to alot of people about it. The general consensus was to top off with fresh fuel and carry plenty of extra racors. If it has Detroits its gonna polish the fuel on a long trip. I ran 200 miles using fuel out of both tanks. Did not have any issues but did have a fair amount of black stuff in racors. I ran them on "both" and used 10 micron instead of 30. Changed the filters and topped off again with fresh fuel. Did about a 100 mile round trip the other day and let the engines idle while we fished. I did not see any visible black stuff in racors on return. I would second the opinions above about polishing the fuel instead of disposing of it. If your tanks are full you are going to have 1200 gallons to deal with

[manorden]

I haven't completely ruled out polishing but I was told a good amount of water and slop had been pumped into the tanks when the boat was sitting without an owner. Also the fuel caps were missing so when it rained some water was always able to get directly in the tank. So just to be clear my plan is to get direct access to the tank and pump everything out and then refill it to treat for algae and pump out again. I believe racclarkson is on the right track with what I have to do. I have tried accessing the tank through the flange under the cockpit access but cannot get the screws to budge. Any tips or tricks here? It looks like someone used something to seal it down in the past. Hopefully not 5200... Also where are you able to access the tanks when running to get manual reading with a dip stick? Thanks so much for all the input. Y'all have already saved me hours on google searching.

[Cricket]

Think you're on the right track, was involved with a boat that had sat for 7 years, polisher tried to filter the fuel but it was too far gone so we pumped it. We ended up cutting a few 10 inch holes in the top of each tank to work through, took a pressure washer to the inside and then pumped out that mess before putting in clean fuel.
I'm a big fan of PB Blaster to get stuff unstuck. Maybe some heat will help loosen things up.

[racclarkson@gmail.com]

Good advice from the Crickster. But, I doubt those screws will budge. They'll probably just break off. No worries, just drill them out and retap to next size up. There probably sealant, but even 5200 will come up. It'll take some heat and some flat tools to wedge it up. Just be easy with the tank. It's pretty robust in that area, but nicks around the flange will have to be addressed--so be easy.

Yes you can dip the tanks underway, but best done stopped. Why not install a simple mechanical gauge while your at it?

Here's picture. The flange is about 8" X 8".

IMG_9276.jpg
That's my dipstick (with white graduation) on the right.

[piripucha]

You could also unscrew were the mechanical sendre/dial sits, but you will be limited by the small diameter of the hole, I belive 2".