Need advice on cleaning plastic gas tank

[jkransbottom]

My '77 has been sitting for over a year so I decided to drop the stock skid plate and main tank and clean it out before trying to start it again. The PO must have done some decent wheeling because the whole tank and space between the tank and the skid plate were packed in dirt and gravel that had mixed with oil and water to make a sort of cement that I had to chip out with a hammer and screw driver.

Anyway, I discovered that the stock tank is plastic and that the sending unit had almost rusted away. I just finished pouring the old gas from the tank through coffee filters into a couple of 5 gallon gas cans. What's the best way now to clean the plastic tank? I was going to take it to the car wash and pressure wash it inside and out. Are there any chemicals I can use inside the tank to clean out the old residue without damaging the plastic?

What about the old gas? Is it usable or is there a way to safely dispose of it?

 

[22213evl]

the gas is now parts cleaner, what kind of residue is in the tank?
might want to think about some kind of rubber to put in between the tank an skid plate on reinstall, part of that ( cement ) was the insulation tween the tank and skid.coat the inside of the skid with some udercoating type stuff.

 

[Jonboy69]

To dispose of the gas, you could go out in the open with no flammable material around put it in a container & throw a match on it & run for the hills !

 

[jkransbottom]

Wow, that first pic looks eerily familiar Evl! My garage and driveway were covered in that same stuff. But I must admit, my skid plate looks downright acceptable now that I see yours. I have a jagged, rusted hole where the right side drain hole used to be and some small holes up near where the upper strap attaches, but its solid otherwise. Almost wish I hadn't ordered a replacement skid plate from Tom's now.

I haven't been able to get a good look inside but after seeing the state of the sending unit and the oddly colored gas that came out I figured there's got to be some varnish in the tank. Will washing it out good suffice? What about the metal inserts in the filler tube and vent that keep the plastic from collapsing when you tighten down the hose clamps? Mine are pretty rusted. Can I replace them with something?

 

[lonesouth]

1. grab a length of chain or some nuts and bolts and place them inside the tank
2. add 1-2 cups of acetone
3. tape all of the openings
4. shake like crazy
5. poor out into a drain pan
6. rinse with water
7. leave in sun to dry
8. re-install

 

[22213evl]

1. grab a length of chain or some nuts and bolts and place them inside the tank
2. add 1-2 cups of acetone
3. tape all of the openings
4. shake like crazy
5. poor out into a drain pan
6. rinse with water
7. leave in sun to dry
8. re-install

yep the chain works best, maybe do it twice.
don't know if you can replace the metal, try wire brush and see if it's still structully sound

 

[jkransbottom]

Thanks guys, I'll try it. The acetone won't be a problem with the poly tank, correct?

 

[Pa PITT]

We clean diesel tanks every day at work ole of the techs does his own by using the power washer and soap then drys it with shop towels ..he gets one hour more time on his job ..the other 3 have us send them to the radiator shop and they charge us $65.00 to steam them out ...
...Just don't dry it with a big red fender rag ...and leave it in the tank ...Got any guesses how I know any thing about this ....

 

[lonesouth]

acetone will be fine