So, what is the best way to clean the inside of a gas tank?

[zippy_gg]

While I have the tank out I'd like to get it cleaned inside and out.
I can handle the "out" part but not sure about the "inside".
The fuel level tube is now out; I don't have, yet, the big Allen (21mm I think) key to remove the bottom filter.
There was apparent signs of leaks nor fuel smell.
I've read about "boiling" and POR15 inside treatment, but not sure if this is needed.
Any input appreciated. TIA.

[allaircooled]

No need for a big allen, here is the tool I use. The bottom of a 13/16 Craftsman spark plug socket.

[Ferrino]

I am restoring my fuel tank too and have read a lot of mixed opinions on different sealants and cleaning methods (mostly regarding the degradation of any plastic swirl pot). I've decided to play it safe and give it a thorough cleaning with POR15's "Marine Clean" product, together with a good pressure washer rinse. I think the right treatment depends on the state of your specific tank.

What are you planning for the exterior? I was thinking of POR15 followed by undercoating (although I learned you really need to use a primer in between for the undercoating to adhere to the POR15).

[porwolf]

Here is another fuel tank cleaning thread that may help:

http://forums.pelicanparts.com/porsche-911-technical-forum/741968-engine-died-out-fuel.html

[zippy_gg]

Originally Posted by allaircooled

No need for a big allen, here is the tool I use. The bottom of a 13/16 Craftsman spark plug socket.

Ohhh Clever! Thanks for that tip!

[zippy_gg]

Originally Posted by Ferrino

I am restoring my fuel tank too and have read a lot of mixed opinions on different sealants and cleaning methods (mostly regarding the degradation of any plastic swirl pot). I've decided to play it safe and give it a thorough cleaning with POR15's "Marine Clean" product, together with a good pressure washer rinse. I think the right treatment depends on the state of your specific tank.

What are you planning for the exterior? I was thinking of POR15 followed by undercoating (although I learned you really need to use a primer in between for the undercoating to adhere to the POR15).

I am removing the old finish on the outside, then the Marine Clean and Metal Ready, then followed by the black POR15. Now is seems that people also spray on the black POR15 while it is still tacky so it will adhere...
Still not sure what to do with the interior; I already washed with water and liquid soap, and then rinsed with more water.
Although I had the tank filled with water twice there are still some very strong fuel fumes... I'll use some compressed air later this afternoon and see if it makes a difference.

[E Sully]

Don't use any coatings inside the gas tanks after 1973.5, it can peel off the whirl pot and clogg the lines.
http://forums.pelicanparts.com/porsche-911-technical-forum/768320-cis-gas-tank.html

[allaircooled]

Originally Posted by E Sully

Don't use any coatings inside the gas tanks after 1973.5, it can peel off the whirl pot and clogg the lines.
http://forums.pelicanparts.com/porsche-911-technical-forum/768320-cis-gas-tank.html

This is one of the reasons why I had to replace mine. Besides leaking, previous owner coated the inside with something and it started flaking off.

[nicfranc]

[gordner]

I pulled my tank and after a lot of reading decided to try to clean it via the electrolosys method, and I was absolutely stunned at the results. I just pulled the filter and reistalled the plug, filled the tank basically full with warm water mixed with baking soda. Dropped a steel pipe in with a piece of rubber hose to isulate the bottom and guidline tape to insulate at the tank opening where the rod leaned against the side, hooked up a 12v battery charger at the 6 amp setting (pretty sure it was negative on the steel rod positive on the tank but check that cause it is really important lol) and fire on the juice. Over about 15 min it ran from a 6 Amp draw down to about a 1/2 amp, unhook the power pull the now fully rusted steel rod out, brush clean it to steel and change the water, do it again. Did that about 4 times before it stopped dropping current and when I rinsed it out, it looked like galvanized steel inside, dull but totally clean. Remarkable, and so low on effort it is totally my style of cleaning lol.

[gordner]

And no more crap in the filters or carbs through the full summer. So I know it was beyond visual!

[Robbbyg]

Another good solution, i just did mine a couple of weeks ago

Get about 4 or 5 litres of Apple cider vinegar, (normal cider vinegar works also i assume)
Swish it around n the tank every few minutes then after about half an hour empty it out and do it again if needed.

mine was pretty bad, so much that i cut a access hole so i could give it a good scrub, but i found out about the cider vinegar too late,
it literally rinses the rust away i couldnt believe it.!

I painted tank bay and tank with Rustoleum Rubber spray, after a zinc primer, its good cos it dampens vibration in the tank as well as keeping rust away

[michael lang]

What if your car's tank has gas in it while other things are being done i.e. engine out and car going to body shop for some refinishing. Could be atleast another 6mos before driving again. I've already added Sta-bil but with today's crappy gas you really can't be too sure. Is there something else i should do while my car is not being used? I'm more concerned about the deterioration from ethanol than anything else.

[matt gineo]

This is how I cleaned the interior of my tank. I wouldn't coat the interior with anything because it will probably flake off at some point in the future and I would not have it boiled at a radiator shop if you have a plastic swirl pot.. it will melt.

http://forums.pelicanparts.com/porsche-911-technical-forum/661056-cleaning-fuel-tank-without-damaging-plastic-swirl-pot.html

[BeeMaster]

Is there a noticeable advantage/ difference using a rubber spray rather than just por-15 and por-15 paint?