Old gas and sludge (stuck, pun intended...)

[TJ Hemrick]

All,
Does anyone know if:
1. There is anything that will get rid of sludge/varnish in an old tank
2. Has anyone successfully had a tank boiled at a radiator shop and the swirl cup did NOT melt or get damaged?

I'm working on an 84 that sat for a few years. OK, probably several years.

Anyhow, wasn't getting any gas to the injectors. Pulled the pump, hot wired it, no gas comes out. Tapped it, soaked it, etc. Same result.

After that, I went back to the tank. Disconnected the lines and it was barely dripping out. Maybe 1 drop every 45 seconds or so. I tried a short piece of wire but no luck. I got the tank out and drained it but with what little light I could get in there, it looks really plugged.

That in itself is really weird. I put 2 gallons of MEK in that tank and 10-15 gallons of fresh gas letting it sit for a few months and hoping to get rid of most of the varnish. It was like pouring water in there. Absolutely nothing....

Now, I'm not opposed to cutting an access hole in the top like I've seen done here on the list. It works well and can either be welded back or left with an access port type cover. I'd prefer not to have to go through the whole process of working on a tank but that seems to be my only option.

Thanks,

TJ

[TJ Hemrick]

Yes, I searched the archives but nothing about this directly.

[DanielDudley]

POR 15 Marine Clean Quart

Yes I have used it, and yes it works.

[sc_rufctr]

Originally Posted by DanielDudley

POR 15 Marine Clean Quart

Yes I have used it, and yes it works.

Great product... No end of uses but make sure you don't get any on bare skin. If you do rinse with water immediately.

[tdskip]

Some radiator repair shops will clean them.

[TJ Hemrick]

Wow, that's crazy. I would have never in my wildest imagination bought a non-petroleum based solvent to try for this. Thanks for the advice!

TJ

[RichardNew]

If you find a shop to clean the tank don't let them line the tank with anything.

We used to do it in the old days but some of the new gasoline formulations eat into the material and cause big problems.



Richard Newton
Gasoline Basics

[Jack Stands]

I think tank sealers are now available that are comparable with the ethanol laced fuels that are being sold these days. Certainly check with the radiator shop.

[911T1969]

+1 on Marine Clean

[Mark Salvetti]

Does a 1984 have a plastic swirl pot, or did that end in 1983 with CIS? Might want to peer inside just to make sure, as everyone seems to advise not to coat these tanks. The coatings don't stick to the plastic.

Mark

[SCadaddle]

Originally Posted by Mark Salvetti

Does a 1984 have a plastic swirl pot, or did that end in 1983 with CIS? Might want to peer inside just to make sure, as everyone seems to advise not to coat these tanks. The coatings don't stick to the plastic.

Mark

My friend that has restored many 911/912/356 and other makes fuel tanks (we restored my 69 912 fuel tank) has assured me that the coatings such as "Redkote" will not adhere to the plastic swirl pot. For those tanks he fabricates a metal swirl pot that the coating will adhere to. He's a forward thinking kind of fellow, to the point of discussing with the chemist at Redkote on the "breaking point" of how much ethanol in the fuel would cause an issue with the coating. He performed his own experiments and I seem to remember up to 15% was ok.

The procedure he performs is to steam clean inside and out, actually cut the tank in half, sandblast the inside, if there are small pinholes they get welded up, if a swirl pot tank he fabricates a metal swirl pot, the tank is then welded back together, pressure tested and finally coated on the inside. The outside of the tank is cleaned up and the correct coating/paint is applied. It is very labor intensive, and if one wanted to go the "easy" route it isn't quite as cost effective as buying one of the Dansk repro tanks that has no outlet filter screen and isn't quite so "easy" once you have to cobble up things to make the fuel line connections, but it's not too far off budget wise and it is done right.

I would post photos of the process, but those are his trade secrets. If you would like to contact him about his services drop me a PM and I'll have him contact you.