McGyver style in-tank Fuel Strainer

Some of you may have been following my ongoing challenges with sludge (bio-mass) in one of my fuel tanks. Through persistence and sweat I have been able to remove the fuel, cut a 6” access port through thick stainless, and remove the thick sludge that is accessible through the access port. Unfortunately the tank has four chambers separated by top to bottom baffles. Even with a fuel polisher and 80 psi of return fuel pressure there remains significant sludge in the two farthest chambers.

I have killed the sludge with Killem and removed the fuel. Currently I am attempting to dry the tank and the remaining sludge by circulating air. The good news is the sludge reduces in size significantly as it dries. It also sticks like glue to the bottom of the tank. Hopefully it will remain stuck permanently. In case it doesn’t, I have McGyvered a strainer over the pickup tube using a plastic Gatorade bottle. I drilled many holes in the bottle to allow fuel in but small enough to keep large debris and flaked sludge out. My plan is to periodically transfer the fuel and go into the tank to remove any detritus that may have moved into the cleaned compartment with the pickup tube.

I’m sure some will say this is a bad idea..... but I figure it is worth a shot. If for some reason, the Gatorade strainer begins to decompose I will make a better strainer out of stainless. Here are photos for your amusement.

Fuel will eat up the plastic. I'd think disintegrating/dissolving plastic isn't going to be helpful to the situation. Yes, as a temporary hack I applaud the effort, but I wouldn't leave it in there for any duration.

A clear plastic bottle like that is probably PET. If you find a polyethylene container it will last more or less indefinitely in diesel.

I had a problem with pickup strainers getting clogged. I just removed them so the dirt goes through to the fuel filter where it’s easier to deal with.

That looks like Asphaltene. Use an additive specific to this to eventually dissipate. MEK will also render it a liquid (and how you test to determine if that is the problem).....

https://www.amazon.com/gp/product/B00G4TWBDA/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Now that you have relatively easy access to the tank, I think your idea isn’t bad. I would go ahead and make a S/S basket around the pickup. I like the overall idea, just not the plastic.

DDW said:

A clear plastic bottle like that is probably PET. If you find a polyethylene container it will last more or less indefinitely in diesel.

Click to expand...

White plastic milk bottles are polyethylene and should work fine. I looked at a quart of half and half in our fridge and the bottom says HDPE- high density polyethylene. HDPE is very resistant to hydrocarbons, as noted above.


David

I like the idea. You might try eliminating the holes in the side of the bottle but leave the top open. As long as you don’t run the tank down below the lip, you will be pulling fuel from whatever level the lip of the bottle is at. Maybe a 4” bottle? Then no fuel enters that is less than 4” off the bottom.

HopCar said:

I had a problem with pickup strainers getting clogged. I just removed them so the dirt goes through to the fuel filter where it’s easier to deal with.

Click to expand...

You are absolutely correct.
The goal is to remove the crud from the tank, not prevent it from coming out.
Aggressive multi stage filtration will easily handle it.

Brass or bronze window screen is available at any hardware store.

A couple of hose clamps will hold it in place.

I think the bottle idea while it would work, wont allow the tank to clean itself. The gunk will build up on the bottom again.
And that gunk may also be due to water gets in the fuel and microbial activity and old diesel sitting in tanks a long time rotting away unused.

Little drops of water form in fuel even from humidity in the air, That water-fuel interface allows fungus's and bacteria to grow and that degrades the fuel with their waste products. Acetobacter does this in gasoline. Hard to believe, but gasoline also grows bacteria if it gets wet. I think a big help would be a sealed fuel system, just like cars and trucks have today. They use a VPR vapor pressure relief tank cap, that keeps humid air from easy continual access to the fuel. And if diesel out gasses hydrocarbon components, then it will stay fresher in a sealed system.

Every since I changed to a Perko VPR fuel fill, with vent back to the fill, all my gasoline fuel issues on the boat went away. The gas stays fresh in the tank forever it seems. And I stopped treating the fuel with preservatives.
And since the vent hole over the side is gone, much harder to spill fuel into the water. I also added an Attwood fuel demand valve so a slightly pressured tank of max 1 psi due to the fuel cap, wont allow fuel to leak if a fuel line is disconnected.

I think the point here is the gunk is bad enough and the chunks are large enough that blocking them IN the tank and then going back INTO the tank to clear them out is the point.

This thread makes me wonder/worry what the inside of my tanks look like...

wkearney99 you are exactly right. The point of the "mud strainer" is to prevent the large pieces of sludge from sucking up into the pickup tube and shutting off fuel flow. That is exactly what happened one day leaving me temporarily stranded at the worst time. This setup (or some better variation) will allow me to periodically remove the dead sludge as it works it way from the contaminated baffles to the clean baffles. Eventually I hope to be able to remove most of it through a combination of this manual process and chemicals. I was shocked to find the amount and thickness of sludge in my tank. I would advise anyone to keep an eye or their tanks if you have access. This has been a nightmare to deal with. Fortunately I'm not one to give up!!

https://www.plasticsintl.com/chemical-resistance-chart



I too was leery about that bottle in the diesel fuel so I looked up a resistance chart. See attachment above. Looks like the PET was a good choice.

Personally I don't like the little screen inside as those have been known to cause lots of trouble. ANy bits of your goo that get through the bottle should be allowed to get to the filters. They will be small enough to get sucked to the filters.

I can see the goo will now collect and stay on the small screen and likely plug the screen.

JMO

C lectric that is a good point about the screen. It is probably overkill and asking for trouble. The chart you sent was extremely helpful. Seems like I should stay with the gatorade bottle. I did by a 32 oz Nalgene HDPE bottle to use insted but I don't know that it would last any longer than the PET bottle. Thoughts?

How about a mason jar without the lid?