Cleaning out an internal fuel tank.

[Wightdiver]

Searched the forum but was unable to find anything specific on this.

My project RIB has an under deck stainless fuel tank. Whilst I do not think it is too bad the previous owner (and he did appear to be a pretty genuine guy) did suggest that he had suffered with water in the fuel previously. The boat has now been standing for 12 months, so whilst I am carrying out the rebuild I plan to clean out the fuel tank, but what is the best way?

My thoughts were to syphon out the petrol through the fuel filler and empty the tank. Once empty, depending on what actually comes out add in clean fuel, about 20 litres at a time, splosh it around (that should be fun) and repeat the process again and again until clean. One thing I do not know is if the tank has internal baffles. Anyone out there know if a Porters Renegade had baffles in the tank? I know they were fitted with both 25 and 35 gallon tanks but don’t know which I have at the moment.

I know that this is not the perfect solution but with a decent filter separator installed afterwards I think it should be OK?

I really, really do not want to dig up the deck and remove the tank and wondered if you think this would work or if anyone on here had any better ideas?

Regards

Andy

[Chris]

THe question to ask is how did water get in in the first place.

As for emptying the tank the challenge will be how good the furl pick up is. if it is positioned so it will literally drain every drop then you should be fine doing as you suggest. If there is no other access hatch then this is the best you can do.

My advice follwing draining the tank would be to fit a high quality water seperating filter and always carry a couple of spare cartridges and then monitor it closely.

[Wightdiver]

Thanks Chris

Glad that my ideas are not totally off the wall.

Andy

[Erin]

Difficult to be certain, but if you feed a siphon pipe down the fill tube you need to make sure you get it right to the back obviously. Better to use the outlet pipe because if the tank is well made it will reach pretty much right to the lowest point. In my experience you don't get much sediment out of petrol tanks by sloshing around. Petrol is so 'thin' that sediment falls out of suspension very quickly. Better to just fit a good separator and maybe circulate fuel through for few hours if you can, kind of like a fuel polishing system. Make sure you use a petrol safe pump tho.

[Pete7]

Andy, I took a couple of gallons of water out of a Tohatsu doing just as you are suggesting. Drain the fuel into a white plastic drum and leave to stand for a while. The fuel will float above the water so pour this back in and then ditch the remaining water petrol mix. Repeat half a dozen times. What remained was a filter full of fuel that came out the first time the rib was used on the water.

Peter

[Nos4r2]

<edit> The below only applies AFTER you've done what Pete said above-it WON'T work on lots of fuel but it will clear any remains in there out.</edit>

Empty the tank via the outlet.

Chuck in a bottle of Wynns Dryfuel mixed with a gallon of fuel. Slosh it about if you can.

Empty it again.

Put it back in, slosh it around.

Empty it again.

Chuck a gallon of fresh fuel in then empty it again. Bin both gallons of fuel-if there's any salt in there, you don't want it in an engine.
You need to get as much of the fuel/Dryfuel/water mix out as possible-it'll run on it, but it'll be a pig to start.

Fill with fresh fuel and go play

[Hightower]

Defiantly like the tube down the fill tube and a siphon to make sure every last drop of fuel is removed. perhaps you can tilt the RIB and trailer enough to make sure the fuel collects in the end of the tank your siphoning it from.

Once all the fuel is removed I would just refill it with clean stuff from a good reliable garage forecourt and purchase a water separating filter like I have on mine. You can buy these from Panda Fuel Diesel Injection Service center by Sainsburys. The body is the most expensive part but the filter is like £3 a pop for future changes.

If you like, you could come over and have a look at mine plumbed in.

[Wightdiver]

Hightower, PM sent.

Andy

[Wightdiver]

Originally Posted by Erin

Difficult to be certain, but if you feed a siphon pipe down the fill tube you need to make sure you get it right to the back obviously. Better to use the outlet pipe because if the tank is well made it will reach pretty much right to the lowest point. In my experience you don't get much sediment out of petrol tanks by sloshing around. Petrol is so 'thin' that sediment falls out of suspension very quickly. Better to just fit a good separator and maybe circulate fuel through for few hours if you can, kind of like a fuel polishing system. Make sure you use a petrol safe pump tho.

Hi Erin

I did consider this route but thought that it would most probably have a filter at the bottom? Perhaps I will try a mixture of both.

Thanks for your comments.

[Hightower]

Originally Posted by Wightdiver

Hightower, PM sent.

Andy

No pm yet?

[Chris]

Once you have done all of this it would be worth getting the tank pressure tested.

[Wightdiver]

Originally Posted by Hightower

No pm yet?

Just sent again

[Hightower]

OK I've seen what has happened. You haven't PMed me, you've emailed me instead. I'll give you a ring early next week to arrange a time.

[Wightdiver]

Thanks Andy