Icky Rust in Fuel Tank

Be careful with what you use in the tank. Some of the sealers that are just poured in will start to desolve after a while. That great "new gas" will cause the sealer to start coming apart. ( I know ).

I talked with a freind of mine today who said that after cleaning the tank that maybe droppping a magnet into the bottom of the tank would gather up the loose rust? Does the pickup come out or do you have to drill out the rivits to take it out? Or does it screw in somehow? Same for the sending unit! Are there any really good filters out there to install in the line to the carb? Ones that filter out the rust really good? How about those small filters for motorcycles? They seem to get the rust out good.
I have gone through two carbs already. Puut a new one on last night but I am not hooking the fuel up until I am sure the rust is out.
Thanks.

OK., here is what I am goin gto do. I ordered that kit from Eastwood. With all the materials to coat the inside of the tank. I freind of mine that restored motorcycles told me NO NO NO , do not use it. It eventually comes off in sheets and wraps around the pick-up resolting in NO GAS. So I am going to start by draining the tank and washing it out. I am goint to try and get a brush inside the tank to scrub the top and then rince it really good with water. I was told to use something to eat the rust, like muratic acid but to watch out for the fumes. Don't know if I am going to do that yet. Tonight I am going to drain the gas and let it air out for a while. Then do the water and air it out to get rid of all the fumes. Then if I can find a brush and modify it to get the top if the tank scrubed I will. Stay tuned in.

In all fairness to it being a tricky issue would you not feel more secure with taking the tank to a gas tank repair facility and having them do it? Your having to remove it anyway so this way they can go and clean it while checking for other problems....

I say this more in light of you don't get very many opportunities to remove the gas tank because of the necessity to remove the engine that you may as well leave it in the hands of people who do it for a living... If you do it wrong what a hassle it is to go back and fix...

Just my thoughts....


Dave

I've used muratic acid to remove rust from gas tanks and all kinds of steel/iron parts with great success. Muratic acid is dilute (Typically about 20% by volume) hydrochloric acid. It's commonly used to etch concrete, clean swimming pools, etc. and can be purchased at hardware and spoll suppliy retailers. It will definitely dissolve all rust (iron oxide). It will also off-gas chroline so do it outside and don't breath the fumes. If you use it as purchased and dont dilute it, I'd recommend a gallon or two (it's inexpensive) and reposition your tank so that all surfaces will be immersed for an hour or two each. Alternately, you can use several gallons, fill the tank full and let it set for several days (dilute solutions are slower acting). When your through, if you dilute it with water, say 50:1 or better, it's realtively harmless and you could wash down your driveway with it. Even at 20% it won't burn you but may stain your skin or mildly irritate. Where latex gloves. Make sure the tank is vented and that you do this outside. If you seal the tank it will off-gas to potentially explosive pressure. You also need to make sure that you remove the filler neck, the sending unit, and anything that is not steel. It will completely dissolve aluminum and zinc (try it with a beer can). When your through, you will have the most rust-free tank you've ever seen, but you're not done. Mix a box of baking soda in with a tank of water and this will neutralize the residual acid on the inside surface of the tank and prevent any acid from migrating into your carb. and attacking any aluminum surfaces in your engine. After you do this drain well and set it in the sun to dry. All you'll need to do is poke around to make sure that you tank wasn't rusted through anywhere. -You'll be done with rust forever. By the way, iron oxide (rust) will not stick to a magnet. This method might pick up pieces that still have some ferrous content but not iron oxide. Good luck.

Can I do this procedure while the tank is in the car? Some have assumed the tank is out. It's in the car still. I would suppose I can do it if I fill up the tank enough to get the rust off the top of the tank. I just spent some bucks getting the headers and exhaust done so I don't want to take the engine and trans out.

me again., does the sending unit screw out? Pop out". I noticed the ring around it is rivited. Also does the gas pick-up line screw off too (on the top of the tank)? THanks

Most sending units screw in. I would drill out the pop rivits and remove the sender. You'll need to remove the rear window and trim (it's only held in by friction. Pry it out carefully with a screwdriver). Then the sender can be pulled out the window opening. When you put it back, use 6mm metric screws- the tank is already tapped. This whole thing is like brain surgery when doing it in the car. Please consider pulling the engine and trans, then the tank. You'll need to replace all of the hoses in the cooling system and fuel system, if the car's sat long enough to rust the inside of the tank. The outside of the tank needs painting, too, and the body & frame area behind the tank usually needs attention.

Well., got the back glassout of the car (BROKEN). I was being so careful and then....It cracked so I just kicked it out! SUCK!!! Oh well. Got the sending unit out and used the muratic acid. Worked real well. I only had rust on the bottom of the tank. The rest of the tank is really clean. When I got the old gas out is was nasty. The rust is not completely gone so I think I am going to re-do the muratic acid again to get the rest out. Any advice where to get a back glass? (good thing is now I can detail on the sides real good!) I was thinking I could have a piece of glass made if I need to. They are flat as a pancake.???? Thanks in advance

Well I used a second dose of muratic acid last night to dissolve the rest of the rust in the tank. I went with a 28% solution instead of 20% and left it in for two hours. It worked beautifully and now there is NO rust in the tank. I rinsed with baking soda and water several times. While I got the back glass out I am goint to clean up the area that I can't usually get to from the front real good and re-paint. Thanks for all that helped!

You mentioned you removed the rear glass. Can you explain how you did this? Thanks!

You sure wound up with troubles because of gas tank rust, but there are three solutions to your cracked rear window problem. First, the window can be replaced by a piece of Lexan, quite cheaply. Second, there are quite a few used rear windows available reasonably. Third, why not run without the glass? I've had mine out for 5 years for the following reasons: they are 3 lbs of useless weight apiece, they substantially interfere with cleaning the back window, and they do nothing: the airflow follows the contour of the car the same whether the window is there or not. Just push the frame back into the body and be done with it. Many of us have done this- you'll fit right in....

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Originally posted by Bosswrench:
You sure wound up with troubles because of gas tank rust, but there are three solutions to your cracked rear window problem. First, the window can be replaced by a piece of Lexan, quite cheaply. Second, there are quite a few used rear windows available reasonably. Third, why not run without the glass? I've had mine out for 5 years for the following reasons: they are 3 lbs of useless weight apiece, they substantially interfere with cleaning the back window, and they do nothing: the airflow follows the contour of the car the same whether the window is there or not. Just push the frame back into the body and be done with it. Many of us have done this- you'll fit right in....

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quote:

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Originally posted by Bosswrench:
You sure wound up with troubles because of gas tank rust, but there are three solutions to your cracked rear window problem. First, the window can be replaced by a piece of Lexan, quite cheaply. Second, there are quite a few used rear windows available reasonably. Third, why not run without the glass? I've had mine out for 5 years for the following reasons: they are 3 lbs of useless weight apiece, they substantially interfere with cleaning the back window, and they do nothing: the airflow follows the contour of the car the same whether the window is there or not. Just push the frame back into the body and be done with it. Many of us have done this- you'll fit right in....

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Boss,

Ouch. I think he took out the back window NOT the side window.

Disregard my question....didn't see where you BROKE and then KICKED your glass out!! Don't be so hard on yourself, the rear glass is easy and inexpensive to replace.

Boy., didn't know this was going to be such a hot topic. Well buess what. I got the tank all cleaned out and I put gas in the tank (5 gal) and could not get gas to come up out of the tank. found out the pick up tube had a hole in it and was sucking air...Hummmm what should I do? Well I got a little creative and drilled a hole in the sending unit top between the electical wire connections. Then I used a brass fitting on top and a plastic washer and nut on the bottom.On the under side I strapped a piece of fuel line (stainless)to the sending unit with nylon ties. and then angled it down so it would pick up fuel at the bottom of the tank. It worked great. So my tank is still original and I did not have to drill any holes in the tank. Of course I did all this with the BIG back window out.

I'm glad everything is working. I'm not sure if the sending unit was in the car when you drilled it. Seems like it would be tough to get out with the tank in the car. Mild acids are one thing, but I'd caution you about drilling, machining, or introducing any potential ignition sources to a fuel tank. A spark from the bit, drill brushes, static discharge, or short to ground will yield a most undesirable result (ka-boom). I'm glad you resolved your problem but give fuel vapors great respect.

Of course the sending unit is out of the car when I drilled a hole in the top. The BIG back window was out of the car while I worked on the tank. It sure is a lot easier getting to stuff with that back window out. While I was at it I replaced all the hoses, stripped and painted the water bottles, etc. I really just wanted to clean the car up and drive it for a while without restoring the whole engine bay compartment (which is what I did with the engine in the car) I am doing two ground ups right now on Mustangs and didn't want to tangle with another. Next job is the brakes!

I'm getting in on this kind-of-late, but I have a simular problem, in that my fuel tank has a slow leak. It seems like a seepage, or something and I can't tell where it is really coming from. I notice in some of the other responses the mention of a tank sealer. Where would I purchase some? How could I evaluate the soundness of the tank in general? I was thinking that the tank was probably shot! Tahnks in advance!

Sam