# Rust in gas tank



## ultrarunner2020 (Feb 3, 2020)

Hey guys;
My brother has an Airens model 921030 Deluxe 28in snow thrower. It has the Airens AX snow engine. The machine is about 5 years old.
Last time it snowed, he was unable to start the machine. He had pushed the primer bulb twice, and apparently flooded the engine. But there was another problem that I believe was the true cause of the problem; bad gas. The gas in the tank was probably 3-4 years old! I had added Stabil to the gas when it was fresh, but I don't think it can keep gas usable for that long.


Yesterday, I drained all of the old gas from the tank. When I shone my light into the empty tank, I noticed a lot of crud on the bottom. It looked like rust to me. The tank is metal.
There wasn't anything I could do without removing the tank, and I wasn't prepared to do that, so I poured in some new gas (with Stabil) and installed a new spark plug. The engine started and ran well.
But I worry that some of that rust will get into the gas line and foul up the carburetor. Unless of course there is a screen on the gas outlet in the tank; then the rust would just clog up the outlet, and swishing it around a bit might dislodge and allow the machine to run again. I won't know that until the machine is used again.


So, I would like to remove the tank and clean it out.
I saw a YouTube vid where a guy pours some clean gravel (purchased at HD garden dept) into the empty tank, and agitates it for 15-20 minutes (by hand). It really did clean up the rust.
After that, he poured in some apple cider vinegar and left it overnight. That really cleaned it up nice.


How difficult is it to remove the tank? And is there a screen at the outlet to prevent the rust particles from going into the carburetor? 

I'm just hoping that either I can get this done before the next snow, or we get lucky and get through this season without any more trouble; then I can do the job in the spring.


Thanks for your help.
FW


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## oneboltshort (Dec 16, 2019)

That process is for obviously rusted tanks IMO. If you think you have rust bits in yours use a cheapo HF extendable magnetic pick up tool and see what you get. There is a screen inside the tank it's part of the fuel valve assembly.


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## Oneacer (Jan 3, 2011)

If your concerned, just put on an in-line filter for now.

BTW, you should never leave any machine for years without running it periodically.


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## orangputeh (Nov 24, 2016)

I use aquarium gravel to clean out rust in tanks. if you wanna do it right it tanks more than 15 minutes. I do it for a couple days. and then do the vinegar thing, let it sit and then flush out.

also change or install a filter as mentioned. 

your carb is probably a mess.


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## crazzywolfie (Jun 2, 2014)

no need to worry about contaminating the fuel system. there is usually a strainer on the fuel tank outlet. the problem may come if the fuel outlet strainer clogs.


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## RC20 (Dec 4, 2019)

I have had that danged rust get into the carb bowls through a fine filter, fortunately it settled there and I could get out.
Good idea to look. Also if there is rust there was water that may be in there as well.


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## cdestuck (Jan 20, 2013)

your ethanol fuel went into ''phase separation'' where moisture, gas, and ethanol all seperate into layers. And the water lays on the bottom, setting up the rust. Taking off a tank isnt usually to bad. Just start taking screws and bolts apart. you'll get it done. Do the stone deal with vinegar and youll be fine.


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## ultrarunner2020 (Feb 3, 2020)

Thanks guys;
The machine has been used each snow season - with the same gas - and I think it started back in Oct, but didn't want to start a couple weeks ago when we had some snow. Isn't that always the case...
I realize I shouldn't have left the old gas in the tank; I wasn't paying attention.


Is there any reason to use apple cider vinegar instead of white vinegar? I have always used the white vinegar to clean my warm-mist humidifiers - but then, that's not rust I'm cleaning; it's mineral buildup from the water.


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## classiccat (Mar 1, 2014)

I can't really speak to the vinegar but the suggestions make sense. Evaporust is another one that I imagine would work well (and its reusable.)

I've saved a few metal tanks in various states of decomposition by swishing around nuts/bolts with Marvel Mystery Oil or automatic transmission fluid. Rinse out with seafoam then fill with fresh stabilized fuel. The nice thing about nuts/bolts is you can use a magnet to retrieve them and they don't shed anything.

At the end of each season, drain the gas and oil the tank with fogging oil; I remove and make sure all of the surfaces get a good coating.

During the season, keep the tanks full of fresh stabilized fuel (preferrably E0).


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## Seaweed (Jan 18, 2016)

Maybe the apple/cider smells better?


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## 2.137269 (Nov 15, 2019)

oneacer said:


> If your concerned, just put on an in-line filter for now.
> 
> BTW, you should never leave any machine for years without running it periodically.


fuel filter is in the tank to hose connection fitting . 

op clean out the tank rebuild the carb your bound to find it all clogged up with e gas crud


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## Fat City (Feb 11, 2017)

LIME AWAY rust stain remover is a good way to clean metal tanks . Rinse, and dry the tank . Add a few ounces of Lime Away, do this outside, the fumes are strong . Let the concentrate work, invert tank to attack rust on top underside.
After a few minutes, fill tank with warm water, shake, and rinse throughly . Allow to fully dry before refueling . Add a mesh type filter Avoid the paper filters, they trap water, that can freeze, clogging filter .


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## 2.137269 (Nov 15, 2019)

doing restoration work we use a lot of Evapo-Rust also use the eastwood product https://www.eastwood.com/rust-remover-eastwood-rust-dissolver.html both are good stuff fill the tank with it, let it sit, flush reuseable is a up side 
lets all try to remember that a lot of the clone engines have a plastic fuel tank fitting screwed into the tank,part of it is a fine mesh fuel filter that tends to clog up


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## Kiss4aFrog (Nov 3, 2013)

If it's a metal tank that's worth keeping like something old that's collectable you can also Kreem it.

https://kreem.com/fueltankliner.html

I was going to try and save the tank on my Ford tractor but when I tried to get the loose rust out before I started in I found way too much crap and chose to just go new.
Hard to tell from the photo but that is one huge pile of flakes. It looks flat but actually more of a pyramid with it being 8-9" in the center. 

.


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## crazzywolfie (Jun 2, 2014)

but the tank on a 5 year old machine that is still running likely won't be nearly bad enough to need replacing. it likely just needs a rinse out to remove any small debris to keep the strainer from clogging and it will be fine. in my opinion it is not worth going overboard cleaning the tank. just rinse it out with hot water and should be good.


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## Oneacer (Jan 3, 2011)

@Kiss,

Now that is a rust clogged tank …. lol


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## RC20 (Dec 4, 2019)

crazzywolfie said:


> but the tank on a 5 year old machine that is still running likely won't be nearly bad enough to need replacing. it likely just needs a rinse out to remove any small debris to keep the strainer from clogging and it will be fine. in my opinion it is not worth going overboard cleaning the tank. just rinse it out with hot water and should be good.



Age does not matter, its water and rust forming.
If rust is there you have to deal with it, it won't just go away. 

Cycle tank wound up with a Kream type coating as rust got into an area that it would not come out of (seam maybe). Upshot was a lot of screwing around when what it needed was a one shot nuclear deal which fixed it.


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## crazzywolfie (Jun 2, 2014)

RC20 said:


> Age does not matter, its water and rust forming.
> If rust is there you have to deal with it, it won't just go away.
> 
> Cycle tank wound up with a Kream type coating as rust got into an area that it would not come out of (seam maybe). Upshot was a lot of screwing around when what it needed was a one shot nuclear deal which fixed it.


age makes a huge difference. if the engine is running there clearly isn't water in the system since water sink to the bottom of the tank and would be first sucked into the carb. the tank likely only has a light coat of surface rust that is nothing much to worry about. if it was a 50+ year old machine then yes the tank is most likely roached if it had water sitting in it but i don't see a 5 year old tank with bad gas being that bad.


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## RC20 (Dec 4, 2019)

Oh come on. 

I can pour a gallon of water in a new machine and have an issue.
My Yamaha is 20 years old and its never had water in the tank. I am fortune that my weather conditions do not lend to that and we have good gas stations. 

So age is not the issue (it can be part of it, its not the sole issue) its exposure to water, however that occurs.
Not often these days but bad fuel out of a gas station can do in a brand new machine. 

And the fuel pickup is not at the bottom of the tank, its up a bit, so no you won't see water right away.
I have not idea how the water got into the cycle tank, it sure as **** did and it was brand new (2 years old when I bought it) 

Water and air exposure = rust. And it does not take 20 years to do so.


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## crazzywolfie (Jun 2, 2014)

you can't seriously think the 10-50ml or so of water that might sit below the fuel outlet is going to cause a tank to completely rot out and need to be replace after 5 years.


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## Spawn.Qc (Dec 24, 2019)

oneboltshort said:


> That process is for obviously rusted tanks IMO. If you think you have rust bits in yours use a cheapo HF extendable magnetic pick up tool and see what you get. There is a screen inside the tank it's part of the fuel valve assembly.




Rusted metal is not magnetic....


Envoyé de mon iPhone en utilisant Tapatalk


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## oneboltshort (Dec 16, 2019)

Spawn.Qc said:


> Rusted metal is not magnetic....
> 
> 
> Envoyé de mon iPhone en utilisant Tapatalk



Perhaps for a science experiment of pure "rust" powder after it's completely been broken down through chemical reaction. I doubt that's the issue here on a 5 year old tank. I have pulled lots of particles out of fuel tanks with an extendable magnet. There is enough ferrous material still present to attach to a magnet. 

You can get the vast majority of particles out of small engine tanks (metal or plastic) with a simple fluid extractor also.


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## tabora (Mar 1, 2017)

Spawn.Qc said:


> Rusted metal is not magnetic....


It is not magnetic, but a strong magnet will certainly pick it up. After I descaled the rust on my car-hauling trailer prior to painting, I used my broom magnet to pick up all the residue.


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## 2badknees (Jan 28, 2017)

I don't know how something non magnetic can be picked up by a magnet. Unless I'm missing something, someone should rethink this. I recently replaced all the freeze plugs in my truck. It has a cast iron engine. Before I installed the new plugs, I shoved a cow magnet ( a magnet swallowed by cows, for what I don't know) into the opening. A glob of rusted metal flakes and grit adhered to it with each freeze plug location. I'm no engineer, but things gotta make sense.


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## crazzywolfie (Jun 2, 2014)

i got a hub cap full of rust in my basement that came out of a air compressor tank. it is definitely magnetic even using weak fridge magnets. i wish rust wasn't magnetic. it is one of the biggest annoyances. usually any time i need a magnet they are covered in rust particles and it is nearly impossible to wipe the small particles of rust completely off.


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## oneboltshort (Dec 16, 2019)

Magnets will pick up rust:grin:
Spawn.Qc's statement that "rusty metal is not magnetic..." can be correct, but has nothing to do with a magnets ability to pick up rust particles.


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## tabora (Mar 1, 2017)

Rust is not magnetic, but the iron in it can be attracted to a magnetic object, i.e. a magnet.

*magnetic*
adjective
mag·​net·​ic | \ mag-ˈne-tik 

1 *: *possessing an extraordinary power or ability to attract
2a *: *of or relating to a magnet or to magnetism
2b *: *of, relating to, or characterized by the earth's magnetism
2c *: *magnetized


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## WVguy (Nov 24, 2018)

2badknees said:


> ...I shoved a cow magnet ( a magnet swallowed by cows, for what I don't know.


Hey, I grew up in suburbia and even I knew that one!

It is to prevent (and I'm not joshing you) "hardware disease". Yup, that's what they call it when cows swallow stuff they're not supposed to and it makes them sick. The magnet keeps it where it'll do the least amount of damage.

https://en.wikipedia.org/wiki/Hardware_disease

Now, what this has to do with snow blowers I have no idea....


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## RC20 (Dec 4, 2019)

> Rust is not magnetic, but the iron in it can be attracted to a magnetic object, i.e. a magnet.



Iron is not magnetic, its Ferromagnetic. That said at normal temps it and rust is attracted to a magnet. 



You can induce magnetic field in it (xformers) so its kind of so what and why are we so picky. 



Magnetic is close enough.


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