Cleaning a 1969 gas tank.
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Cleaning a 1969 gas tank.
I have a clogged gas line filter. When I looked into the gas tank, I could see a lot of rust scale. Is it possible to do a reasonable cleaning without dropping the gas tank? My thought is to drain the tank and use a blower to evaporate the remaining gas and vapors. When I'm sure it's safe, I'd use a rubber line attached to a shop vac to pick up the rust. I'd appreciate any comments. Thanks.
Team Owner
Joined: Sep 2006
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From: Westminster Maryland
Hi DM,
How much of the surface is rusted? Is it enough that there may be a leak in the near future?
Just removing the loose particulate from the tank MAY not be enough.
Depending on the condition of the tanks inner surfaces they may need to be treated too.
I believe there are some 'coatings' that can be applied to the tank but I don't know how reliable they are.
So, how bad is it?
Regards,
Alan
How much of the surface is rusted? Is it enough that there may be a leak in the near future?
Just removing the loose particulate from the tank MAY not be enough.
Depending on the condition of the tanks inner surfaces they may need to be treated too.
I believe there are some 'coatings' that can be applied to the tank but I don't know how reliable they are.
So, how bad is it?
Regards,
Alan
Thread Starter
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Joined: Oct 2017
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About 10 years ago the original tank rusted through and was dripping on the muffler. I replaced the tank. So I'm thinking this tank is structurally sound, just has rust in it. I'm older now and if I can avoid crawling under and dropping the tank, I'd be a happy camper. Thanks.
Safety Car
Joined: Apr 2006
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From: BC
I just finished my 69 last week. I'm starting to get up there in age at 68 and it was an easy job. You can get a complete tank kit with everything from the tank to straps, pads, bolts, gaskets, new sender, filter and hoses for about $380 from any vendor here.If I was just going to clean out the tank on the car I would drop the sender out the bottom then use compressed air from the top to blow everything out. I would not use a vacuum in there as any fumes entering the vacuum can blow it up due to the electric motor running it. Sucking volatile fumes through a vacuum is not a good idea.
Le Mans Master
Joined: Aug 2010
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From: Central Texas
Originally Posted by Alan 71
.
I believe there are some 'coatings' that can be applied to the tank but I don't know how reliable they are.
So, how bad is it?
Regards,
Alan
I believe there are some 'coatings' that can be applied to the tank but I don't know how reliable they are.
So, how bad is it?
Regards,
Alan
After a period of time rust was back.
I wished a would have replaced the tank the first time.
If your tank is rusted I would recommend tank replacement.
Last edited by Street Rat; Oct 21, 2017 at 10:08 AM.
Thread Starter
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Thanks, that makes sense. I just watched a YouTube video on making a vacuum using the Venturi principle and compressed air. No sparks with this setup.
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Thread Starter
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I purchased a new "Early 1969" tank. When we got it out we found the sender unit was completely clogged. It required putting the project on hold until the new sender came. My recommendation, if you're changing out the tank have a new sender unit "at the ready." If you don't need it, you can return it. Right now I'm waiting for that sender unit to arrive.
Team Owner
Joined: Sep 2006
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From: Westminster Maryland
Hi DM,
I'm surprised the 'sock' at the end of the sender's pick-up tube didn't get clogged instead of the sender itself.
The must have been LOTS of junk in the tank!
Patience!
Regards,
Alan
I'm surprised the 'sock' at the end of the sender's pick-up tube didn't get clogged instead of the sender itself.
The must have been LOTS of junk in the tank!
Patience!
Regards,
Alan
Thread Starter
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Alan, the seam on that "sock" had ripped so all the crud in the tank plugged the tube. A friend attributed it to the ethanol and additives in today's gas. I'm pretty sure squirrels didn't get into the tank and gnaw on it.
Race Director
Joined: Apr 2009
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From: Charlotte NC
Because you installed an in-line fuel filter. Not knowing where you installed it. I would make an extra effort to blow out and clean the fuel line BEFORE the in-line filter you installed.
Some people put an in-line filter right back near the fuel tank..and others cut there steel fuel line going to the carburetor and install it there.
IF your in-line filter is located between the fuel pump and the carb...keep in mind that a lot of the rust can collect in the bell reservoir portion of your fuel pump.
And the sock can not rip due to ethanol...because that does not make sense or is even logical that it only effected that one area of the sock. IF ethanol effected the sock..it would be in much worse shape.
DUB
Some people put an in-line filter right back near the fuel tank..and others cut there steel fuel line going to the carburetor and install it there.
IF your in-line filter is located between the fuel pump and the carb...keep in mind that a lot of the rust can collect in the bell reservoir portion of your fuel pump.
And the sock can not rip due to ethanol...because that does not make sense or is even logical that it only effected that one area of the sock. IF ethanol effected the sock..it would be in much worse shape.
DUB
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Because you installed an in-line fuel filter. Not knowing where you installed it. I would make an extra effort to blow out and clean the fuel line BEFORE the in-line filter you installed.
Some people put an in-line filter right back near the fuel tank..and others cut there steel fuel line going to the carburetor and install it there.
IF your in-line filter is located between the fuel pump and the carb...keep in mind that a lot of the rust can collect in the bell reservoir portion of your fuel pump.
And the sock can not rip due to ethanol...because that does not make sense or is even logical that it only effected that one area of the sock. IF ethanol effected the sock..it would be in much worse shape.
DUB
Some people put an in-line filter right back near the fuel tank..and others cut there steel fuel line going to the carburetor and install it there.
IF your in-line filter is located between the fuel pump and the carb...keep in mind that a lot of the rust can collect in the bell reservoir portion of your fuel pump.
And the sock can not rip due to ethanol...because that does not make sense or is even logical that it only effected that one area of the sock. IF ethanol effected the sock..it would be in much worse shape.
DUB
Race Director
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From: Charlotte NC
The only inline filter is the stock filter after the fuel pump and before the carb. The strainer was completely destroyed. Not sure what would have caused that much damage while it was "protected" inside the tank. Are you sure the 1969 thread used to sew up the strainer was ethanol resistant? I sprayed Gumout into the fuel line where it connects to the fuel pump. I then used compressed air to blow the Gumout out the other end. I'm now sure the line is clear. I'll see if I can get a picture of just how bad the strainer was damaged.
I do know that the bend on the sending unit where the sock can either be jammed against the bottom of the inside of the fuel tank..or it can be more relaxed. When I install new sending units on the cars that I can see the sock and this tube. I often time tweak the tube so the sock is not being pinched against the bottom of the tank.
DUB
Le Mans Master
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Only unobtainium plastic holds up for 50 years submersed in gasoline and water and alcohol and God knows what.
Race Director
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From: Long Island
I have tried to clean / coat a few tanks in my days.
I would not do it again.
Replace the tank and install a new sock. Replace the rubber lines and blow out the solid fuel lines with compressed air ( disconnect both ends) .
It is a cheap piece of mind.
I would not do it again.
Replace the tank and install a new sock. Replace the rubber lines and blow out the solid fuel lines with compressed air ( disconnect both ends) .
It is a cheap piece of mind.
Le Mans Master
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Well worth it not to chase your tail later.
Race Director
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From: Charlotte NC
And I have replaced sending units where the sock was fine but the sending unit portion was bad. And I actually have some in my shop just for the heck of it for those who need 100% original parts for whatever reason...I have them
And even with the sending unit out in the air for years..the plastic does not dry out and crumble. So the 'unobtainium plastic' GM made them out of is just that.
If yours are crumbling...then I guess they are crumbling.
DUB
Le Mans Master
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I have removed factory sending units and the sock does not shatter or fall apart as mentioned.
And I have replaced sending units where the sock was fine but the sending unit portion was bad. And I actually have some in my shop just for the heck of it for those who need 100% original parts for whatever reason...I have them
And even with the sending unit out in the air for years..the plastic does not dry out and crumble. So the 'unobtainium plastic' GM made them out of is just that.
If yours are crumbling...then I guess they are crumbling.
DUB
And I have replaced sending units where the sock was fine but the sending unit portion was bad. And I actually have some in my shop just for the heck of it for those who need 100% original parts for whatever reason...I have them
And even with the sending unit out in the air for years..the plastic does not dry out and crumble. So the 'unobtainium plastic' GM made them out of is just that.
If yours are crumbling...then I guess they are crumbling.
DUB
Do I work on as many of these as you, no way. But I do help out all these guys around here, and have seen this ruin quite a few cruises for some guys.
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I chatted again with the guy who removed the sender from my tank. He told me he could see the split seam while the unit was still in the tank. As he was removing the sender from the tank, the strainer struck the tank opening and shattered. The new sending unit has a plastic strainer and a different type of float. I'm not a corvette mechanic nor do I play one on TV, just saying what we saw on my early 1969 convertible.