Cleaning diesel tank with little access
Posted by dwkfym@reddit | sailing | View on Reddit | 17 comments
I have a fuel tank with only fill spout, return, and vent holes in the tank. The pickup is welded on and not removable.
Is it possible for a professional (or me!) to agitate and clean out all the gunk sitting at the bottom of the tank? I really don't want to cut an access hole at the top, since that means I have to cut the cockpit deck above it too.
ruxing@reddit
Haven't tried this on a boat but have done it on vehicles and motorcycles. Get a bunch of metallic bolts, put them in the tank, slosh it around a lot, and then get a magnet to pick the bolts out of the tank. Then, use whatever you come up with to pump and filter the fuel out.
dwkfym@reddit (OP)
That's SOP for motorcycle tanks etc to get the rust out. But if this tank was easily removable I wouldn't have posted this question to begin with
ruxing@reddit
Shake the boat! It will mix the gunk up... I understood your initial question. Don't Be an a** when some tries to help!
silverbk65105@reddit
I am in the petroleum business. I have cleaned many of my tanks.
First get the fuel out, I use a wet dry vac to get every last bit. You might have to fashion your own sucker. I use pvc, flex, whatever is needed, that I duct tape to the vacuum hose.
Inspect the tank. you might need a camera. See what you are up against.
If you have sludge and debris in there that is stuck, meaning you cannot get it out with the wet dry vac, then blast it with a pressure washer. Use only water, no soap, detergent or degreaser. Vacuum all that out. They make attachments that can articulate, so you can reach all areas. On the fuel barge we use a mega version of this idea, ours rotate vertically and horizontally and shoots 180 degree water at high pressure. They sell little ball version on ebay that you adapt to your pressure washer lance. You can google butterworth machine to wrap your brain around it.
good luck
dwkfym@reddit (OP)
thanks! I was thinking about if there was any way to articulate the pipe - I think my tank has a single baffle in it. that butterworth machine is intense.
silverbk65105@reddit
When I do residential tank pumping, sometimes the house has low ceilings or a shelf above the tank top. So I have to fashion what I need on site. I will use short sections of pvc pipe, couple them together, or use a section of flex in the middle to make it work.
I have done everythng from the tanks on the 420K gallon barge at work to my 5 gallon tractor fuel tank
dwkfym@reddit (OP)
I think there is a baffle in the tank. single baffle dividing the tank by half. I think I'm in for a long-haul - I probably need to polish every month, and every sail, biocide shock treatment, before I can get the tank acceptably clean without having to cut an access hole.
mckenzie_keith@reddit
You should cut at least one inspection plate in the top of the tank, empty it into jerry cans and clean the inside. If the tank has baffles, you may need to make two inspection holes.
If you can pull the tank out of the boat that makes it even easier.
They can agitate the tank and filter the fuel, but what is really needed is to bring the tank to a dry and clean condition. You will need to do this every two years or so.
In extreme cases, people will cut holes in bulkheads or deck plates or whatever to create access.
You can pump the existing fuel through a racor filter as you evacuate it from the tank. Add some biobor to it. Put it back in the tank later.
fuckin_atodaso@reddit
What you're looking for is called "fuel polishing". I am sure you could probably DIY this, but it is usually a couple hundred bucks to have a marina or boat service do it for you.
light24bulbs@reddit
I don't think fuel polishing is the right answer, but I want to point out that if you have a low pressure injected engine with a distribution pump you can just turn the key to "run" and the pump will cycle all the fuel through your filters after a few hours and they will either clog or not and you can change them without the engine quiting while you're under way. The fuel system is identical to a fuel polisher.
dwkfym@reddit (OP)
My pickup keeps getting clogged instantly. I gotta get back there with a tank of pressurized air and blow it out. Unfortunately I have a Perkins 4.107/8 with a mechanical fuel pump. I'd add an electrical pump, but I really don't want to add to an already complicated engine (water heater, water muffler, etc. Its already a mess of exhaust hoses)
Willing_Park_5405@reddit
Fuel polishing is the process via pumps and stages of filters of cleaning fuel for near term future use. Op is asking about tank cleaning.
JebLostInSpace@reddit
I had a similar challenge a couple years ago but at least my pickup was removable. I would say you're unlikely to be able to do much in your case. The only thing I can think of to try is several iterations of filling the tank maybe 1/4 full, rocking the crap out of the boat, emptying the tank, and repeat. It won't result in a true cleaning, but might let you suck out most of the loose particulate. Change your filters often. Are you using any kind of biocide?
dwkfym@reddit (OP)
Thanks. I thought of something similar too - siphon most of it out, then 'garden hose it' with a polishing system with a stronger fuel pump. Basically rotate the polisher return hose all around as much as I can. But keep repeating it until fuel comes out relatively clean. Even if it takes me two days.
It's a new to me boat. I'll definitely be using biocide once I get the tank fairly clean.
JebLostInSpace@reddit
Yeah the polisher loop is good because then you're not creating as much dirty fuel to dispose of. It's worth trying, and then just change your filters a lot the first season until they start coming off clean. If the problem persists you're going to have to either install a new tank or cut an access port. Can you get to the tank from below deck instead of coming in through the top and having to cut a hole in your deck?
dwkfym@reddit (OP)
I only have maybe 3 inches of gap between the deck and the top of the tank. Its a major PITA to get the tank out in a P365. People either cut em out or remove the engine to do it :(
I may have a removable non OEM fuel tank though since the previous owner says its 40gal and not 50gal.
lutherdriggers@reddit
Oof what a pain... You can cut a hole in your tank and make an access if you have a flat area to screw it into. https://fueltankparts.com/products/6od-x-4id-bolt-in-tank-clean-out-access-plate
The other part is to make a polishing system. A 12v fuel transfer pump and some fuel line to route the fuel thru your primary fuel filter and back to the tank.
Use some copper tubing or (car) brake line WI some brush material strapped to it and vigorously scrub the sides of the tank. Tank might have baffles that get in the way.
Add a shock treatment of biocide.
Run the polishing system for many hours.
Might have to transfer fuel out to install clean out port, and then back in, so need Jerry cans.
Last bit not least, I did all this and my tank still have me troubles a couple of years later. I would also consider putting in dual primary filters I can switch between to hot swap them when engine running.