Rusty gas tank? I have your solution! (1 Viewer)

[FJ80Steve]

So I bought a 92, everything was ok with it beside the fact that it had some "been sitting under a tree for 10 years" problems.

Ran fine until you needed to push the gas further than you would for normal driving (passing, uphill, ect.) and after testing sensors, new fuel filter, plugs/wires/cap/button, I still couldn't find the source of the problem. Then I pulled the fuel sending unit to check the sock filter..... Tank was RUSTY AF

I ran across an old motorcycle tank thread somewhere on the web that suggested Muriatic acid, had before/after pics, looked promising, so I decided to go grab 10 gallons and give it a shot.

HOLY SH*T! It worked better than I could've ever dreamed! Here's the before/after pics of my tank.

 

[FJ80Steve]

What I did was drain and drop the tank, stuck a water hose in it and flushed it out for like an hour, dumped that and banged on it with my hand to break as much of it up as possible, quick flush with water again, then 3 rounds of acid 2 gallons at a time in the tank, about 10 minutes each, and thorough rinse with water again. While the acid is in the tank you'll want to (very carefully) tip the tank in all directions so that it gets everywhere.

Saved me about 500 bucks

 

[Hack]

Did you consider putting fuel tank sealant in after the cleaning? POR-15 makes a good one.

 

[FJ80Steve]

I've read too many bad reviews on tank sealants. If you don't prep the surface properly the coating won't stick and I don't want to risk it considering all of the baffling in the 80 series tank.

 

[gummycarbs]

If you have an old battery charger laying around, electrolysis works really, really well, and you don't have to deal with acid.

You're right about sealants, in my opinion. I've de-rusted several tanks with acid or electrolysis. They don't rust if you keep them full of fuel like you're supposed to. If you're worried, or storing it, put in a teaspoon of oil with your fuel.

 

[Red Merle]

What type of acid do you use, where do you buy it and what do you do with it when you are done?

 

[FJ80Steve]

I am about to do one more round of acid, just because I have two more gallons. My plan is to rinse it really well and get it as dry as possible, then throw in a gallon of gas with a teaspoon of marvel mystery oil and swish it all around so surface rust (hopefully) wont form.

 

[FJ80Steve]

What type of acid do you use, where do you buy it and what do you do with it when you are done?

Muriatic Acid, got it from home depot for like 5.88 a gallon. This stuff will burn the fk out of you also, so keep that in mind.

I manage a body shop, we have hazmat disposal. If you don't know what to do with it call a local shop and ask them what they do with theirs.

 

[gummycarbs]

My plan is to rinse it really well and get it as dry as possible, then throw in a gallon of gas with a teaspoon of marvel mystery oil and swish it all around so surface rust (hopefully) wont form.

The last time I did a motorcycle tank, I dumped in a few pints of 99% rubbing alcohol, swished it around, dumped it out, and repeated. The alcohol absorbs water and drains out. I think I followed with oil in alcohol, because I was going to ship the tank. No rust formed.

 

[Red Merle]

Muriatic Acid, got it from home depot for like 5.88 a gallon. This stuff will burn the fk out of you also, so keep that in mind.

I manage a body shop, we have hazmat disposal. If you don't know what to do with it call a local shop and ask them what they do with theirs.

Cool, I may look into that for some rust removal on my undercarriage. I am worried about getting burned though, so I am hesitant to do it, but it looks like works incredibly well. Will the acid harm things like rubber or plastic? I am obviously not a chemist

 

[retrofive]

Cool, I may look into that for some rust removal on my undercarriage. I am worried about getting burned though, so I am hesitant to do it, but it looks like works incredibly well. Will the acid harm things like rubber or plastic? I am obviously not a chemist

Do your homework on muriatic acid. Nasty stuff. I would look at alternatives.

 

[gummycarbs]

Cool, I may look into that for some rust removal on my undercarriage. I am worried about getting burned though

Use "naval jelly", which is phosphoric acid in gel form. It won't get everywhere and the rust is converted to an inert layer.

 

[Red Merle]

Thanks for the advice, guys. I will look into the naval jelly. I used that stuff a long time ago and I remember that it worked, it just took a long time. I definitely don't want to burn myself, poison my dog or create a Super Fund site in the process. I have been using my wire wheel on the grinder after having everything soak in bar chain oil and that works pretty good, it's just tough to get into all the little nooks and crannies that way and a chemical solution is appealing in those cases.

 

[FJ80Steve]

I wouldn't suggest Muriatic acid for undercarriage rust, don't think you could safely apply or wash it off.. And you don't want the stuff to just drain into a yard or ditch.

Look up Rust-a-mort and POR15

 

[Red Merle]

I wouldn't suggest Muriatic acid for undercarriage rust, don't think you could safely apply or wash it off.. And you don't want the stuff to just drain into a yard or ditch.

Look up Rust-a-mort and POR15

I use POR 15 and I think it works alright if you get most of the rust off. I haven't used Rust Mort though and that looks like something I would like to try out. I have more experience trying to get rid of rust or prevent it than I prefer, but I am always looking for ways to make the process more effective and have better long term outcomes.

Thanks for the suggestions!

 

[BILT4ME]

Vinegar will also remove rust, but slowly, then you must get it well rinsed or it will make it get worse.

Do not use POR-15 on the INSIDE of a fuel tank.

DO not use or drip muratic acid on your concrete driveway. It WILL eat it.

For the bottom of the truck, I would consider the naval jelly due to the phosphoric action because it coats the surface to stop the rust. Then you use paint such as POR-15 or Fluid Film or Bar Chain Oil or spray all your used oil on the bottom of your truck (isn't that why we FIX the oil leaks?)

We used Naval jelly to remove the rust from plow shares in the spring because of how it would allow the plow to clear itself. At the end of the season, we had to heavily grease the faces of the plow shares to last through the winter.

We would put on the Naval jelly, let it sit for a day, then wipe it off and rinse.

Using the POR-15 is great except you need to remove all the dirt and oil from the area as well or it peels off.

 

[retrofive]

Vinegar will also remove rust, but slowly, then you must get it well rinsed or it will make it get worse.

Do not use POR-15 on the INSIDE of a fuel tank.

DO not use or drip muratic acid on your concrete driveway. It WILL eat it.

For the bottom of the truck, I would consider the naval jelly due to the phosphoric action because it coats the surface to stop the rust. Then you use paint such as POR-15 or Fluid Film or Bar Chain Oil or spray all your used oil on the bottom of your truck (isn't that why we FIX the oil leaks?)

We used Naval jelly to remove the rust from plow shares in the spring because of how it would allow the plow to clear itself. At the end of the season, we had to heavily grease the faces of the plow shares to last through the winter.

We would put on the Naval jelly, let it sit for a day, then wipe it off and rinse.

Using the POR-15 is great except you need to remove all the dirt and oil from the area as well or it peels off.

The POR15 tank kit no good?
POR-15 Fuel Tank Repair Kit

 

[BILT4ME]

The POR15 tank kit no good?
POR-15 Fuel Tank Repair Kit

I'm the guy that is telling everyone to NOT place any kind of sealer INSIDE a tank. On the POR-15, I wouldn't use it inside the tank because I've seen it peel on the OUTSIDE of parts that were cleaned. Don;t get me wrong, I think it's a GREAT product, but placing it inside a vessel that you cannot see, feel, and touch every spot in it, you are relying on a PERFECT cleaning and faith that it will work. I have talked to too many people that have sealer failures in about 2 years + and having a sealer fail is WAAAY worse than having rust.

Do what you want. It's your tank.

As for the POR-15 Fuel Tank Sealer kit.......I have no hands-on experience with it. I have no opinion specifically on that kit. Why don't YOU use it, then report back every 6 months. We'll know how great it is when you stop reporting how great it is.

 

[retrofive]

I'm the guy that is telling everyone to NOT place any kind of sealer INSIDE a tank. On the POR-15, I wouldn't use it inside the tank because I've seen it peel on the OUTSIDE of parts that were cleaned. Don;t get me wrong, I think it's a GREAT product, but placing it inside a vessel that you cannot see, feel, and touch every spot in it, you are relying on a PERFECT cleaning and faith that it will work. I have talked to too many people that have sealer failures in about 2 years + and having a sealer fail is WAAAY worse than having rust.

Do what you want. It's your tank.

As for the POR-15 Fuel Tank Sealer kit.......I have no hands-on experience with it. I have no opinion specifically on that kit. Why don't YOU use it, then report back every 6 months. We'll know how great it is when you stop reporting how great it is.

I had it in a old vdub tank. No issues, but then again I didn't apply it myself. So

 

[gummycarbs]

Tank lining systems have been hotly debated on the internet for literally decades. Some say they peel due to not following the directions correctly, not etching the metal before application, and some think that modern ethanol blends damage them.

What I can definitely say is that I've removed rust from several tanks, never lined any of them, and never had a significant rust issue return. Keep your tank full and seal out moisture and you should be fine.