Advice on cleaning fuel tank

[dmksails]

I thought I might have some algae growth in my tank, so I drained it and opened the inspection ports. Yikes! Bottom of tank is covered with a hard tar-like sludge! Not having much luck with putty knife.

Any advice on how to remove this without using dynamite or a flame thrower?

[Shenandoah52]

Can you take flakes of the grime and test them for different solvents to dissolve the grime? See which solvents act the fastest with the least amount of fumes.

I just cleaned a tank just like yours but I was able to remove the tank. It was a 16 gallon tank and yours should be a 32 gallon tank but you may need to clean it in place so the method I used would be different. That stuff can be a bear to remove if it is a hard tar-like sludge like you said. Mine was the same and took a lot of mechanical action as well as the chemical action. Test samples can really be your friend here.

[Checkswrecks]

Put a gallon of acetone in and seal it up for a couple of days. If the tank is out of the boat then MEK, but you have to be much more careful with it.

First remove the hoses and cap the ports or you may ruin them.

[a64pilot]

I’d start with mineral spirits as acetone’s fumes are very strong.
I’m sure it would work but those fumes would overwhelm me.

I believe what you may have is called asphaltanes, pretty much what it sounds like and I assume mineral spirits will help dissolve it.
Mineral spirits is paint thinner and goes by other names too depending on where you are, I believe white spirits is one name.
It’s pretty much what is used in parts washers in auto repair shops to cut grease and grime.

[dennismenace111]

Originally Posted by a64pilot

I’d start with mineral spirits as acetone’s fumes are very strong.
I’m sure it would work but those fumes would overwhelm me.

I believe what you may have is called asphaltanes, pretty much what it sounds like and I assume mineral spirits will help dissolve it.
Mineral spirits is paint thinner and goes by other names too depending on where you are, I believe white spirits is one name.
It’s pretty much what is used in parts washers in auto repair shops to cut grease and grime.

Dont use the odorless mineral spirits from Home Depot...You want the real mcCoy. Although, I agree, ACETONE will probably soften up the sludge quicker.

[tkeithlu]

Now you know why refiners put detergents in gasoline, and why you don't want to leave old gasoline in a tank very long. You've got the stuff that was in the gasoline cut from the cracking column that was supposed to be down at the bottom with the road paving stuff. I wouldn't hold too much hope for quick removal with mineral spirits, at least without a brush, because this came out of solution with a more volatile hydrocarbon, gasoline.

[a64pilot]

Originally Posted by dennismenace111

Dont use the odorless mineral spirits from Home Depot...You want the real mcCoy. Although, I agree, ACETONE will probably soften up the sludge quicker.

Yes, that God awful milk looking stuff is junk. I bought it once to clean my winches with, never again.

[boat driver]

Originally Posted by tkeithlu

Now you know why refiners put detergents in gasoline, and why you don't want to leave old gasoline in a tank very long. You've got the stuff that was in the gasoline cut from the cracking column that was supposed to be down at the bottom with the road paving stuff. I wouldn't hold too much hope for quick removal with mineral spirits, at least without a brush, because this came out of solution with a more volatile hydrocarbon, gasoline.

???? thought it was concerned with diesel growth?

first question- did you put any bio diesel into the tank?
if not- then simply brush liberally parts cleaner and let sit- another neat but mislabeled use is paint brush cleaner (the brush solvent for old dried brushes- but ideally get the one with high VOC if can-new stuff soso).. This must be eventually wiped out, but it tends to soften much of the cake.

[a64pilot]

Originally Posted by tkeithlu

Now you know why refiners put detergents in gasoline, and why you don't want to leave old gasoline in a tank very long. You've got the stuff that was in the gasoline cut from the cracking column that was supposed to be down at the bottom with the road paving stuff. I wouldn't hold too much hope for quick removal with mineral spirits, at least without a brush, because this came out of solution with a more volatile hydrocarbon, gasoline.

Surely it’s Diesel? I’ve never seen that with gasoline.
But yes he is going to need a stiff brush and mineral spirits, but scrubbing with a brush and time will dissolve it.
Kerosene will work too, maybe not as well though.
Just Acetone, MEK or MIK in an enclosed space scares me.

[tkeithlu]

Same refinery concept applies to diesel; dmksails didn't specify. Agreed on the acetone etc. "Better living through the creative use of volatile hydrocarbons" refers to things going bang in the night. But then, dmksails only expressed a reluctance to use a flamethower (hard to get it into the tank without becoming a crispy critter), and dynamite (quick, but might add several feet to the length of his boat, impairing its bouyancy in the process).

Let's see. I maintain two little gasoline trail bikes, two outboards, and seven gasoline small emergency generators. My solution: Keep fresh gasoline in cans, not the tanks. Write the fill date on each can with a marker pen. After six months empty the cans into available trucks and start over. Leave gasoline in a small engine carborator for more than six months and it loses its volatility. That's the frustrating small engine "it won't start."

What the previous owner did to lay down that asphalt pavement in the bottom of dmksail's fuel tank, gasoline or diesel, truely impresses me.

[dennismenace111]

Originally Posted by a64pilot

Surely it’s Diesel? I’ve never seen that with gasoline.
But yes he is going to need a stiff brush and mineral spirits, but scrubbing with a brush and time will dissolve it.
Kerosene will work too, maybe not as well though.
Just Acetone, MEK or MIK in an enclosed space scares me.

Turn off tge batteries, unplug shore power. Pick a windy day and come up for air often. In my younger days I recovered fabric covered airplanes and control surfaces using nitrate dope thinned with acetone. It's like working with model airplane glue, only we used it in gallon buckets and applied it with 4 inch brushes! The last 4 or 5 coats were sprayed on! My wife claims that it made me the man I am today! Dopey!

[a64pilot]

I’ve done a little fabric work myself.
The worst I’ve ever experienced was Kapsovar Hungary in the middle of winter, it was an overhaul facility for AN2 Colts, and being Winter they had the hanger closed up tight and were doing fabric.
I don’t know how they stood it, I was stoned in five minutes, and had a headache in ten.

[dennismenace111]

I used to recover all the tail feathers for the Prinair planes. They did major overhauls at Opa Locka airport near Miami back in the 1960s and 70s. I'd be brushing on the dope and set the bucket and brush down for a second to adjust or clean the surface and forget where i put the bucket that was on the floor near my feet. We literally had to break every 10 minutes to clear the fog out of our brains.

[KWISPEL]

scraping + steel brush

[gonesail]

how difficult to remove the tank? i would not use acetone while it was in the boat but looks like it will take something like that. otherwise consider a new tank