removing rust from inside metal 6 gal tank?

Home Cookin'

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May 26, 2009
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I have an old 6 gal OMC tank that hasn't been used for 20 years; looks great on the outside and I want to use it in my old whaler, but the bottom (inside) has a coat of rust. What's the best method to remove it?
 

Bamaman1

Lieutenant Commander
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May 15, 2011
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Re: removing rust from inside metal 6 gal tank?

Any rusty fuel tank's not worth the risk of having a problem passed on to your engine.

Either go on EBayMotors.com and find a good used tank or buy a modern plastic fuel tank that'll never have a rust problem.

I have a couple of 12 gallon Moeller plastic tanks for my pontoon boat. They work just fine.
 

DAN M VAGOS

Petty Officer 1st Class
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Jul 11, 2008
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Re: removing rust from inside metal 6 gal tank?

White vinegar yes household vinegar I'm telling you it works like magic I could not believe how well it works. Just pour it in and shack it up and if you have a lot of rust then add some small nuts and or washers and shack it up then ASAP and I meen ASAP you take it out add diesel to the tank to coat the meatal if not then you will have rust back in minutes.
 

foodfisher

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Feb 18, 2009
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Re: removing rust from inside metal 6 gal tank?

A pound or two of roofing nails, shaken well.
 

dingbat

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Nov 20, 2001
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Re: removing rust from inside metal 6 gal tank?

The makers of WD40 make Rust remover soak. Good stuff. Pour it in, drain a little while later and your ready to go. Vinegar will work but presents other problems as noted above. Vinegar is not kind to most plating and protective coatings either
 
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Bob_VT

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Re: removing rust from inside metal 6 gal tank?

AND......... always run an external filter if you use that tank!
 

robert graham

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Re: removing rust from inside metal 6 gal tank?

I've used a couple of handfuls of gravel with some water and detergent...then shake, shake, shake, then rinse....gravel acts as a good abrasive to remove rust and scale. But that old steel tank will most likely continue to rust and corrode, so install a canister filter between the tank and the motor( like the Walmart fuel/water separator filter $27) to protect your. Fuel system and motor..
 

Silvertip

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Re: removing rust from inside metal 6 gal tank?

A length of chain dropped into the tank and shaken vigorously works too. Some of the classic car restoration catalogs have a liquid coating that can be applied inside the tank to seal the inside surfaces after being cleaned. This material is used to seal classic car fuel tanks.
 
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matt167

Rear Admiral
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Sep 27, 2012
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Re: removing rust from inside metal 6 gal tank?

gas tank sealant would work, it's pretty inexpensive too.. x2 using vinegar... Radiator shops could also boil it out but you would need to repaint, and re-decal if you wanted original
 

colbyt

Master Chief Petty Officer
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Aug 9, 2012
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Re: removing rust from inside metal 6 gal tank?

Never tried the vinegar. I recently tried a trick I learned here or some where else for cleaning a carb using pine-sol 50/50 with water. That made the carb look like new and even removed some rust that was on the welsh plug. After the carb look like new I poured the mix into the tank along with a fresh batch and let it sit for 48 more hours. That carb had crystallized crud every where and had not been stated for 7-8 years.

The hardest part of the job was rinsing all the pine-sol away and getting the tank 100% dry.

Installed the carb with a new filter and the engine started on the 3rd pull.
 

Sea Rider

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Sep 20, 2008
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Re: removing rust from inside metal 6 gal tank?

Plastic tanks are cheap, the way to go, once metal tanks rusts will keep on going rusting eternaly...

Happy Boating
 

Home Cookin'

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Re: removing rust from inside metal 6 gal tank?

thanks, all. I have a plastic tank but wanted to use this one since it fits the restored look ('64 whaler). And for that reason I hate to install a water seperator but I probably will.
 

matt167

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Re: removing rust from inside metal 6 gal tank?

That's a planned 'mod' for my old Custom Craft too.. Plastic tanks just don't look right in vintage boats hooked to vintage motors..
 

robert graham

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Apr 16, 2009
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Re: removing rust from inside metal 6 gal tank?

thanks, all. I have a plastic tank but wanted to use this one since it fits the restored look ('64 whaler). And for that reason I hate to install a water seperator but I probably will.

Well if a fuel/water separator will spoil the "antique" looks of your rig, then maybe just a small, in-line fuel filter and mount it out of the way/under the seat or wherever that it won't show....just to filter out any rust/corrosion particles coming from that vintage steel gas tank.
 
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