How do i clean built in an aluminum fuel tank?

[blowin' insider]

I bought an old boat that had sat with gas in the tanks for 10 years , does anyone have any ideas on how to clean it without removing it from the boat ?(that would b a nightmate) . I've tried acetone and flushing clean fuel through it but I'm still getting globs of thick sludgy tar

 

[windsurfer]

Cut an inspection hatch in the top and screw a plate over the hole when you 're done? If you do; try to locate the baffles first.

 

[profisher]

Would pumping steam into it break it all down and give it a consistency that will make it flow out easier?

 

[blowin' insider]

Id need to cut out finished interior peices to make an inspection plate so that's not an option for me but I did triy hot water and dish soap on 1 of the jerry cans that I hadpumped this sludge into that had become contaminated and metholhydrate seems to break it down fairly well and is only 1 quarter the cost of acetone or xylene so I think I may be on to something here . Thanks for the suggestions and if anyone has any others I'd be glad to hear them

 

[Rockfish]

Would pumping steam into it break it all down and give it a consistency that will make it flow out easier?

Possibly steam, hot water,, detergent.and rinse followed by a blow dry. You can get a bit of a look in the tank by looking in the fuel sender hole as it will be the biggest opening. Use flashlights in the filler and vent opening to see a bit better. you may have to remove the tank fittings. You could use a flex shaft video inspection system. It would be hard to do much scraping through that little opening, especially with the internal baffles. I would think much of the goo should be in the stern end of the tank where the pickup tubes are if the tank is mounted along the keel line..

What are you doing with the hundred liters of fuel with gobs of goo in it? Running it through your motors (shudder) or clogging up the Raycors (hopefully). If the goo dissolves it could still end up in the injectors or jets if you are running it unless you can strain it out.

How old is the tank, they don't last forever. If you pull the tank it will easier to clean out and inspect the bottom and lower end welds for crevice and electrolysis corrosion pin holes which will bore through the tank and be full of white powder especially on the welds, and also the general condition of your old boats bilge area below deck.

We just replaced a keel line below deck Al tank with a custom made replacement as well as the whole fuel supply system on a boat of similar size to yours which had an original tank from 1983. It was a lot of work. We went top end on everything and did the labor ourselves except for building the tank. Total cost was around $2400. We were lucky as there was a screwed down deck cover over the 72 inch long tank down the center walkway. If you had to cut up a sealed glassed deck to get to the tank that would be a whole different level of misery.

 

[gunnerlove]

Pump it out. Pour in 5 gallons of regular and a can of Seafoam. Tow it for an hour in the worst roads you can find. Let it sit for a few days, drain and repeat. After a half dozen cycles it will be mint inside. The fact that you cleaned the inside of a tank that is and has been rotting from the outside will soon be the issue.

 

[fishin solo]

Why not just fix it properly? Yeah it sucks but peace of mind is a great thing. Sounds to me the tank is done anyways so you might as well just buy a new one or have one made imo. Fuel is one of the most important things so why gamble??

 

[bigdogg1]

Why not just fix it properly? Yeah it sucks but peace of mind is a great thing. Sounds to me the tank is done anyways so you might as well just buy a new one or have one made imo. Fuel is one of the most important things so why gamble??

Need to give credit to E and D Manufacturing out by Whiskey Creek! Had the same issue as discussed. I cut out my aluminum deck to get to the tank. They drained it, pressure treated it, modified it, cleaned up the baffles, rewelded it and created a neat and tidy removable deck plate should I need it in the future. They were fantastic to deal with and the peace of mind that it is done right is appealing.

 

[casper5280]

Have to agree with others by the time you finish dicking around with it wouldn't be surprize if the tank is done anyway. You should just bite the bullet and replace it.

 

[Jeteye]

I had to get some water scrubbed out of my tank a week or so ago and the fella that did it for me cleans tanks for a living. He showed me some pictures of some real ugly jobs he has done. If you like you can PM me and i will give you his contact info or you can do a google search for fuel polishing in Campbell River and he has an add on Craigs List. He did a great job for me but i was only getting rid of water. Good luck.

 

[blowin' insider]

Thanks for the all the ideas posted here , I'm going to go with gunner loves approach tho as the exterior of the tanks are excellent and it will b a major to remove them . As I said in my post I'm looking for a means of cleaning them without removing the tanks . If there was pitting of any kind on the exterior I may have reconsidered but the boat was garage kept but old gas was left inside the tanks for 10 years . Metholhydrate works well I've found also

 

[blowin' insider]

Pump it out. Pour in 5 gallons of regular and a can of Seafoam. Tow it for an hour in the worst roads you can find. Let it sit for a few days, drain and repeat. After a half dozen cycles it will be mint inside. The fact that you cleaned the inside of a tank that is and has been rotting from the outside will soon be the issue.

I've heard of this sea foam several times now but I haven't seem it in stores , where is it sold if you don't mind my asking ?

 

[gunnerlove]

Pretty much every auto parts store including Canadian Tire.

 

[blowin' insider]

Ok thanks , they didn't have it at he marine suply store , I guess I didn't look hard enough at crap tire . I'll try again thanks

 

[AlK]

I know Lordco carries Seafoam.

 

[Rockfish]

Was talking with McNoob (on this forum) at the marina and apparently he had a problem with goo in the tank and was able to clean it by removing the fittings, draining the tank and pressure washing the inside of the tank, sucking out the dirty water and goo with a shop vac and when it was clean, forced air dried it. If it were to work for you that would be faster and a lot cheaper than 25 gals of gas, $50.00 dollars worth of Seafoam and a lot of bad road driving and truck fuel. I forgot to ask him if he used some sort of flex shaft for the pressure washer. Perhaps you could do both with one shot of gas and Seafoam at the end after drying the tank. .

 

[blowin' insider]

Was talking with McNoob (on this forum) at the marina and apparently he had a problem with goo in the tank and was able to clean it by removing the fittings, draining the tank and pressure washing the inside of the tank, sucking out the dirty water and goo with a shop vac and when it was clean, forced air dried it. If it were to work for you that would be faster and a lot cheaper than 25 gals of gas, $50.00 dollars worth of Seafoam and a lot of bad road driving and truck fuel. I forgot to ask him if he used some sort of flex shaft for the pressure washer. Perhaps you could do both with one shot of gas and Seafoam at the end after drying the tank. .

Thanks I like the sound of that idea also , right now I've got 10 litres of methyl hydrate in each tank soaking until I get a day off work and I'm thinking I'll run it on day tanks in a good chop and drain it afterwards then try he sea foam and fuel and see what comes out . I did plumb all new fuel lines from the nipple out of the tanks as well .
Thanks again for the help it's greatly appreciated