Varnish in Your Gas Tank for Dummies

Varnish in carburetor

The nice people who ran the website eHow.com decided at one point that all their "contributors" (as they termed the freelance hacks who submitted their rubbish) needed to provide biographical information. Supposedly, this was so readers would recognize expertise; but in reality it revealed that many of the people writing about hard science and construction had BFAs in creative writing or BAs in journalism. Still, those bios can be amusing, as in the one provided by Kayar Sprang (real name probably K. R. something): that one crowed that she "specializes in subjects she has expertise in"; a claim that, based on the ItStillRuns.com post "How to Clean Out Varnish in a Gas Tank," was a bald-faced lie.

Srang dug up an ancient blog entry from – get this – a VW Bus fansite. Not only that, but this self-proclaimed "expert" did little more than reword the steps some guy named Richard published for a fuel tank restoration, many of which are specific to a "classic" VW Bus. We're talking about her step one:

"Basically, you'll need to jack the vehicle up and remove the straps that hold it in place."

Not only is that not helpful, we'd like to think that there's more than just "remove the straps." After all, you also need to disconnect the fuel line, the fuel-gauge sensor, the filler tube... Oh, sure, just "remove the straps." Sprang also thought that you could,

"Place a hand full of nuts and bolts into the gas tank to clean varnish out. Roll the fasteners around in the tank for five to 10 minutes. Dump the fasteners out and spray the gas tank out again [with water]."

That step, unfortunately, is for cleaning out the rust. Never mind that few modern gas tanks are steel and don't rust, just think about what that step would do to an in-tank fuel filter and fuel pump. Yeah, that's gonna work. Sprang's resource (which was fine FOR A 1973 VW BUS!) also said to clean the tank with muriatic acid. See previous comment about fuel filters and pumps...

Truth be told, we didn't even have to read to step number one or look over Kayar's "resources" to realize that, like so many eHow contributors before (and after) her, Sprang was peddling bullshit. After all, this is the freelancer who blithely intoned in her "introduction" that,

"If you don't drive a vehicle and you let gas sit in a tank for awhile, it will become old. Old gas looks dark and smells sour. After a couple months or so, the gas will evaporate and leave a varnish residue in the tank."

Yeah right: a "couple months or so"... Maybe a couple years or so, "Kayar"! Not only that, but all she needed to do was refer people to commercial products for cleaning fuel systems, stuff like Gumout® and STP fuel treatment. They contain solvents that will dissolve varnish and run it through the combustion chamber. For tanks that have fuel several years old, most advice is to siphon out the fuel, add a solvent such as acetone or lacquer thinner, and siphon that out. Possibly, rinse and repeat.

But take your fuel tank off and rattle around some nuts and bolts? Only a Dumbass of the Day would start there!

DDIY - AUTOMOTIVE