Generator Gas Tank Rust

[D45]

I usually buy used generators only with plastic gas tanks, for a good reason.

This last purchase was with a metal gas tank. After draining the old fuel, I discovered a good amount of rust inside

I removed the tank and hosed it out,but there's still rust chips inside. I even soaked it with simple green. Still bad.

The tank itself is in good shape, not leaking and no exterior rust bubbles or paint issues

Do I pop $75 for a new aftermarket tank?

Or, is there a good product I can use that will remove everything? Is it worth the effort?

 

[stonesfan68]

Try Evaporust.

I've used it successfully for tool rust, and I've seen it used for fuel tanks.

 

[D45]

I need to verify and make certain this product works

I need to watch some reviews

Spending $30 is one thing, but finding out it doesnt work and having to spend $75 then on a new tank isn't cost efficient

 

[djbmw]

You can try a gallon of vinegar... leave it in there for 24 hrs and see if that worked. Then... load the tank up with some abrasive media (steel bb's), strap the tank to your ATV and go off-roading,..
Failing that you can sand blast it for cheap (harbour freight/princess sell cheap sand blasting guns and media).
Once the rust is gone, make sure to coat the inside of the tank with a fuel resistant coating (POR Fuel tank sealer is good).

 

[Max]

My experience with motorcycles would tell me that you need to chemically clean the tank, de-rust it, and then coat it. The chemicals to do that are more than $75.

Vinegar will remove a lot of the rust. But it’s very hard to get the vinegar out, clean it, and dry the tank before it starts flash rusting. One advantage of the generator tank is that it’ll be a lot easier to work with and flush than a motorcycle tank.

If it was me I’d just buy a new tank. You could try vinegar first, but if you do make sure that you remove any pot metal first like a petcock or float (if there).

 

[Firebrick43]

Bunch of old nuts and a tractor.

Put the nuts in side the tank, strap the tank to the tractors rear wheel, jack that wheel up and lock the other brake, and put it in 1st gear and let it rotate for an hour.

Then degrease/clean with a lye based cleaner such as purple power, acid etch, and coat if desired.

 

[PWC Repair]

I've done a few tanks with rust. Use some degreaser and a bit of water and a 2ft section of small chain. Cap off the openings and shake it about 1 minute. You need the chain to slide around on the metal so you have to turn the tanks, shake, turn, shake......very side for 1 minute. Rinse and repeat untill ALL loose/chunky rust is rinsed out. Fill and let soak with white vinegar for a day. Rinse out with rubbing alcohol. Let it dry in the sun........GOOD TO GO!! I use chain cause all you need to do is get one piece of it and you can pull it ALL out of the tank.

 

[Stuart in MN]

Nuts or chain are good but use whatever you have around the house. A handful of shingle nails works good too, they have a lot of sharp edges to help break loose rust particles.

I like Evaporust but there are lots of rust remover/converter products on the market. Depending on how big the gas tank is you probably don't need to spring for a full gallon, it's available in several smaller sizes. One caution about using vinegar or other acidic products - I think most metal gas tanks have a plating of some type on the inside, and they may remove that plating which would make the tank more susceptible to rusting again in the future.

 

[Hank11]

Molasses will remove rust. I’d try that after the mechanical attempts with rocks, nuts, or bolts.

Check out old motorcycle forums. This is a common practice. The difference is a 80 year old tank generally can’t be replaced.

 

[D45]

The tank appears to hold 7 gallons

 

[OccupantRJ]

Drop roofing nails inside, wrap in a moving blanket, then stuff into a concrete mixer for a while.

 

[yatg]

Drop roofing nails inside, wrap in a moving blanket, then stuff into a concrete mixer for a while.

great idea. and a gallon of vinegar should agitate nicely.

 

[PCustoms]

The tank appears to hold 7 gallons

Tank appears brand new.

Is the inside really rusty?

 

[D45]

Yes the inside is rusty

I flushed a ton of rust out but its still bad

 

[D45]

Drop roofing nails inside, wrap in a moving blanket, then stuff into a concrete mixer for a while.

Who has easy access to a concrete mixer lololol

 

[larry4406]

Who has easy access to a concrete mixer lololol

Lash your tank to wooden dowel or piece of rebar and spin it from a drill with zip tied trigger?

 

[djbmw]

Who has easy access to a concrete mixer lololol

A good number of us own them. The idea is the same though... toss abrasive **** in and tumble it (strap it to a raised wheel, the back of an ATV, an old clothes dryer, etc). Then, once the larger chunks are gone... use an acid of some kind. Vinegar is cheap but takes a while. Muraic acid is faster but costs more...

Alternatively, sand blast it.

Or, value your time and just get a new, generic plastic tank

 

[Stuart in MN]

If you don't get results from shaking it, put it in the back of your car and drive down bumpy streets for a while. I suppose there are any number of ways to agitate the tank if you're creative.

 

[no704]

Load it up with your preferred mix of stuff and drop it at a CrossFit gym for a week.

 

[PoorUB]

I have taken my pressure washer and sprayed out what I could. It gets a bit tricky dealing with 2000 PSI and trying to hold down a small gas tank.

 

[theoldwizard1]

My experience with motorcycles would tell me that you need to chemically clean the tank, de-rust it, and then coat it. The chemicals to do that are more than $75.

EvapoRust will get the rust out. Rinse well with a solvent and water, let it sit in the sun for at least a day.

Red Kote works good but it is not cheap and difficult to get on the sides and top.

 

[OccupantRJ]

I have also taken a couple cups of sand and poured into the tank, then using a long extension tube on a blower nozzle, place my gloved hand across the opening to seal it while inserting the nozzle between fingers to contain and seal. Swirling this nozzle in all directions inside creates an internal sand storm to clean the surface. Be sure to remove any outlet valve or such to keep from over pressuring the tank. Once done a petroleum solvent or Dawn detergent flush and rinse will take care of the remaining dust.

 

[Jay H 237]

If it's something you plan on keeping long term and a new tank is still currently available then it just makes most sense to me to just get the new tank than dicking around with the current. You may be able to save the old but if it's as bad as you say I'd wager they'd be some possible thin spots in it or the rust may come back at some point. If it was something you couldn't get a tank for or you're just keeping it short term then I'd be inclined to try saving it.

 

[908Jim]

If it's something you plan on keeping long term and a new tank is still currently available then it just makes most sense to me to just get the new tank than dicking around with the current. You may be able to save the old but if it's as bad as you say I'd wager they'd be some possible thin spots in it or the rust may come back at some point. If it was something you couldn't get a tank for or you're just keeping it short term then I'd be inclined to try saving it.

Agree! We aren't talking about a classic car or vintage machinery here. Replace it, recycle it, and move on.

 

[housewolf]

I have the same problem with a Honda generator tank. I tried everything and couldn’t get it to quit producing rust. Eventually just replaced the filter on top of the petcock and ran with it. It’s been doing fine for a couple of years now. If, when, I start getting trash in the carb again, I’ll bite the bullet and buy a new tank. I spent several hours on it already

 

[Notgrownup]

Buy a replacement tank and know there is no rust , if the rest of the machine works great you’ll be ahead.

 

[D45]

The Honda GX390 clone motor works great and the generator has alot of nice features

I buy and flip generators a few times a month......just never encountered this issue before

I'll try to find a new yellow replacement tank, which should be a 7 gallon tank

 

[D45]

Well Amazon had a lightning deal for the 128 ounce container of Evaporust for $22

I will give this a try and let everyone know how it turns out

 

[Stuart in MN]

Evaporust is handy to have around and can be used multiple times before it loses its effectiveness, so you'll probably find other uses for it in the future.

 

[Notgrownup]

I wish they made Evaponeihbor.

 

[OccupantRJ]

I wish they made Evaponeihbor.

Uh Oh! There’s a bad neighbor hiding story hiding in that comment somewhere!

 

[Notgrownup]

Uh Oh! There’s a bad neighbor hiding story hiding in that comment somewhere!

Just maybe.

 

[captmoto]

I need to verify and make certain this product works

I need to watch some reviews

Spending $30 is one thing, but finding out it doesnt work and having to spend $75 then on a new tank isn't cost efficient

It works. I put it in a nearly 50 year old motorcycle gas tank 5 years ago. It looks like new today. Pretreat the tank with some drywall screws and a little diesel fuel. Shake it up to get the scale out. Rinse with gas and let it completely dry before you use the evaporust. I rinsed with water and then alcohol to completely dry it out.
If it is rusted through though it will convert the rust to pin holes. Just so you know it would have leaked without the evaporust. You can reuse the evaporust again bit on less heavily rusted material.

 

[theoldwizard1]

Well Amazon had a lightning deal for the 128 ounce container of Evaporust for $22

I will give this a try and let everyone know how it turns out

Evoprust will get the rust out.

To TRULY complete the job, you need Red Kote Fuel Tank Liner. Not cheap !

 

[PWC Repair]

Evoprust will get the rust out.

To TRULY complete the job, you need Red Kote Fuel Tank Liner. Not cheap !

I've used that stuff before.......looks like strawberry jam!. Even after curing out, your first tank of fuel will turn reddish. Don't worry about it, it's normal.

 

[D45]

Entire gallon of Evaporust poured in the tank.

I'm going to let it sit in the bottom on the tank overnight

Then every 24 hours I'm going to rotate, move, spin the tank horizontal and vertical and every angle possible

This might take till Monday but I'm in no rush

It has been sitting in the tank for an hour and I can tell its already working

 

[djbmw]

Entire gallon of Evaporust poured in the tank.

I'm going to let it sit in the bottom on the tank overnight

Then every 24 hours I'm going to rotate, move, spin the tank horizontal and vertical and every angle possible

This might take till Monday but I'm in no rush

It has been sitting in the tank for an hour and I can tell its already working

Make sure to pour it back into the jug and reuse it on future projects

 

[Fodeman]

I've done a few tanks with rust. Use some degreaser and a bit of water and a 2ft section of small chain. Cap off the openings and shake it about 1 minute. You need the chain to slide around on the metal so you have to turn the tanks, shake, turn, shake......very side for 1 minute. Rinse and repeat untill ALL loose/chunky rust is rinsed out. Fill and let soak with white vinegar for a day. Rinse out with rubbing alcohol. Let it dry in the sun........GOOD TO GO!! I use chain cause all you need to do is get one piece of it and you can pull it ALL out of the tank.

I like your idea of using the length of chain. I do have 7 gallons of white vinegar to put in the tank, when I'm ready. I also have a couple of handfuls of short hexhead 1/2" bolts to throw in (stuff with some weight and sharp edges).

What type of degreaser did you use, and how much? Something like Mean Green? I have already shot it with hot water through a pistol grip nozzle and got a fair amount of scale sediment out already.

After using the degreaser and chain/bolts, and rinsing, I was then going to fill it brim-full with the vinegar and let it set.

If I'm then satisfied with the results, what did you neutralize with? Or, is that what the rubbing alcohol does? I don't want it to flash rust after the fact.

Finally, did you coat the inside with anything? From what I've read, coating can be expensive. I always use Sta-Bil in the fuel and keep the tank full.

Thanks in advance for your reply, and let me know if it seems like I missed anything.

 

[finn]

Powdered acetic acid and washing soda, using the recipe posted in a hundred threads here.

Costs far less than Evaporust, and works just as well.

 

[PWC Repair]

What type of degreaser did you use, and how much? Something like Mean Green?

If I'm then satisfied with the results, what did you neutralize with? Or, is that what the rubbing alcohol does? I don't want it to flash rust after the fact.

Finally, did you coat the inside with anything?

Thanks in advance for your reply, and let me know if it seems like I missed anything.

I like purple degreaser......I use ZEP, but purple power and castrol super clean are also similar.

I've not seen a need to neutralize vinegar. Just rinse well, dump, then rinse out with alcohol. The alcohol will take the remainder of the water with it so there's no H2o left to flash rust. I HAVE coated a couple tanks in the past with Red Kote (they were BADLY pitted), if you're going to coat it, that's the only one I would use.