Gas tank cleanout

Rodd

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Jan 22, 2008
148
Pearson 424 East Hampton,NY
I had water in the fuel and was not able to use the tank last season-- I operated from 2 six gallon tanks. It's an aluminum gas tank in the boat that needs to be cleaned. I have emptied all the fuel, but notice a lot of coffee grounds like crud in the bottom. My only access is through the small fuel sender hole. I have been told to use a pressure washer and dish soap and try the best I can to clean it. Does anyone have a better idea, or can you confirm this is the way to clean it out?
Thanks for any suggestions!
 
Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
Can you get a shop vac hose in there? I'd think a pressure was followed by shop vac & repeat would work well if you can rig a short enough pressure wash wand to get angles working for you.

Only other idea would be to make a larger access port. Something like this

 
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Likes: Gunni
Oct 25, 2011
576
Island Packet IP31 Lake St. Louis, Montreal
Are you on the hard right now? If yes, you may be able to siphon the remaining fuel form the tank into a jerry can on the ground.

I used this method a couple of years ago when I cleaned out my tank. I also only had access via the fuel sender hole. as well I used a boroscope (check amazon, they are available ~$20) to see inside the tank and used a small diameter flexible copper tube, from Home depot, as a wand to siphon out the remaining fuel in the tank. (If you emptied the tank via the fuel pickup, there will be fuel remaining in the tank.) I rinsed a few times with a couple of gallons of clean fuel and was able to easily see that the tank was clean with the boroscope.

This does require a helper on the ground but is pretty easy and cheap.

Matt
 

Rodd

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Jan 22, 2008
148
Pearson 424 East Hampton,NY
Thanks Matt- yes, I am on the hard. I have already gotten all the gas our of the tank via a combination of siphoning and pumping out by hand the last remaining bit of gas. I need to figure out how best to clean out the remaining sludge thats in the tank.
 
Oct 25, 2011
576
Island Packet IP31 Lake St. Louis, Montreal
Rodd
In my case, the sludge was suspended in the fuel that remained in the tank. Using the horoscope I was able to dto make sure the wand got out all the sludge.
Matt
 

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
Wow, Granger, that is a brilliant part - pre-manufactured access plate. Everyone needs one of those!
 

Rodd

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Jan 22, 2008
148
Pearson 424 East Hampton,NY
I just found a quick connect nozzle at home depot that pivots about 90 degrees. This should let me get a good angle with the pressure washer wand without having to go very far down into the tank (since I am limited by an approx 2 inch access hole through the sending unit hole). I will report back how this works!
 
Mar 26, 2011
3,401
Corsair F-24 MK I Deale, MD
Using a shop vac with gasoline is a Darwin award trick. I hope this is obvious. I spent many years in refineries and have seen the accidents.
 
May 17, 2014
135
hunter 380 Plano, TX
I think the best route would be to hire somebody to clean your fuel. Every few years I hare a guy to come out in the spring and clean my fuel. He is also agitating the fuel in the tank to pull the krud up into the fuel and then is pumped to his filtration system Not that big of a hickey and really gets everything cleaned up. I hope by letting the tank be dry you havent made a hard krud inside. just my 2 cents
 
Mar 26, 2011
3,401
Corsair F-24 MK I Deale, MD
Crud in a gasoline tank is very unusual. You say you had water in the tank. Was it seawater from a fill leak? Very likely you have considerable corrosion and that is the source of the crud. You should have gotten the water out of the tank ASAP.

I would focus on finding the source of the leak and I would start using a good corrosion inhibitor in the gasoline. Biobor EB has tested very well for this.https://www.practical-sailor.com/is...ill-tops-additive-rematch-biobar_10915-1.html
 

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
A Pearson 424 with a gasoline tank? Huh. I thought they all had Westerbeke diesels.
 
Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
Using a shop vac with gasoline is a Darwin award trick. I hope this is obvious. I spent many years in refineries and have seen the accidents.
He has already gotten all of the gas out. There are now dried coffee ground-like particles left in his tank.
 
Sep 25, 2008
7,076
Alden 50 Sarasota, Florida
He has already gotten all of the gas out. There are now dried coffee ground-like particles left in his tank.
Gasoline isn't explosive. The residual vapor is. Regardless, think he is referring to diesel when he said "gas".
 
Jan 1, 2006
7,039
Slickcraft 26 Sailfish
On my Ranger 29 I had a bad gas tank. Orange sludge that was blamed on the alcohol in the gasoline. It wasn't that hard to take the tank out and take it to a radiator cleaning place (Yeah, I know. If only you can find one. But there is one here in Southold) who cleaned it out and coated it. I had no more problems. Prior to that I was an expert in the four minute carburetor rebuild. One time going into Three Mile Harbor four minutes wasn't fast enough.
See if you can get the tank off the boat. You can also check for corrosion as thinwater suggests.
 
Mar 26, 2011
3,401
Corsair F-24 MK I Deale, MD
Gasoline isn't explosive. The residual vapor is. Regardless, think he is referring to diesel when he said "gas".
I thought "gas" was strange, but he repeated that 4 times. I certainly wouldn't confuse the two. He said fuel once, but I take gasoline to be a fuel in the generic sense.

I've seen empty diesel tanks explode due to the heated vapors created by a saber saw or hole saw (two separate events). I've seen the aftermath of two separate diesel tank explosions cause by inadvertent contamination with a few percent gasoline (very common when tankers switch load). It doesn't take as much as you think. In all three cases the people were very lucky. They were thrown a distance but not killed. I've seen a shop vac catch fire when used to vacuum diesel from a small tank.

You can roll the dice, but these are not safe practices and are not permitted under OSHA or by any code.

How would I clean the tank? Power washer and manual diaphragm pump is safe. AFTER the tank is clean you can add an access hole for future cleanings, but the tank must be cleaned first. Filling with water is another option, but if the tank is not spotless, you now have 50 gallons of oily water to manage.
 

Rodd

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Jan 22, 2008
148
Pearson 424 East Hampton,NY
Thanks all for the comments-- I will be pressure testing the tank this weekend to be sure there are no leaks. There has never been any gas in the bilge, so I know the bottom and sides of the tank are not leaking. I may have gotten some bad gas, of perhaps the fuel fill O-ring, or the sending unit gasket? All of these will show any signs of a leak when I do the pressure test.
I will, of course, replace the fuel fill hose and the fuel delivery hose while I have the tank accessible.
 

Rodd

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Jan 22, 2008
148
Pearson 424 East Hampton,NY
I should have mentioned that this tank is not for the 424 ! It is for a Grady-White. It is gas, not diesel.