Best Gas Tank Cleanout Method

[JackM]

Call me crazy, but I just went out and picked up my 3rd Hodaka preserve/restore project bike in less than 3 months. This Ace 100 has had gas sitting in the tank for years, and is pretty gunked up inside. I did one a few years ago, using just a water/vinegar combination and shaking it with nuts, bolts, etc inside. It worked alright, but I've read of other ways of doing it, and I'd like to find out what you people on here have to say. Thanks, JackM

[matt glascock]

No, you're not crazy. I scored a Super Rat just to relive a bit of my past, and here I am 14 Hodakas later. They all started out just like yours, and one by one, they are being put back into service. That's pretty cool. The fuel in left in your tank, albeit a mess, possibly saved the tank from rusting out. I've had good results with a few cycles of acetone and a handful of drywall screws, a distilled water rinse then a good blow drying followed immediately be a good sloshing of premix. Get to that fuel step quickly or it will flash rust before your eyes. I'm sure you know this, but a good in-line fuel filter positioned immediately before the carburetor inlet is essential. Great bike. It looks like it saw light duty only. Perfect start for a preservation resto. Survivors like that are increasingly scarce.

[taber hodaka]

I have not found acetone to work for me at all. The best thing I found to remove old gummy varnish was lacquer thinner, along with clean gravel or nuts bolts ect. -------Clarence

[viclioce]

SeaFoam works well too! It's got a lot of Naphtha in it. And I like BBs because they won't dent the tank. I agree with Matt, get to that premix quick! Victor

[MTrat]

An extra tip here for plugging the fuel tap holes when cleaning the tank. Take a 1-1.5 inch piece of fuel line that just fits in fuel tap opening; 'screw' a snug fitting old bolt into one end of the hose and thread the hose/bolt plug into the right fuel tap opening. Repeat on the left =). It's easy on the threads and reusable...And while you're at it, this is a good time to clean, lap and tune those neat old brass fuel cocks!

[Bill2001]

My tank cleaning technique is to clean out old fuel and old, failed tank liner using paint stripper with methyl.chloride. Final rinse is with lacquer thinner. Along with drywall screws and much agitation.
Rust is removed with a chemical rust remover named RoVer from Hach Chemical. Does a very good job. Alternatively, rust can be removed with an acid such as white vinegar.
After rust removal slosh in a rinse of phosphoric acid for rust inhibitor. Dry any residual water out with denatured alcohol.
I prefer to finish the job with a tank liner.
My preference is for Caswell Epoxy tank liner. One alternative is a solvent-based liner such as POR15 or RedCote.

[JackM]

Thanks for the tips. I believe I'll go with lacquer thinner, since its probably more of a varnish/gum problem than a rust problem. I do know that it stinks to high heaven. I believe I used a few foot-long pieces of small chain the last time I did this. Its easy to fish them out with a magnet. Cheers
p.s.
Matt, You say you have 14 of them now? My wife will kill me if I got another one.

[matt glascock]

Its not so bad here. My wife was pretty cool. I don't even mind living in a cardboard hut under the deck.

[JackM]

Well, I tried most of the above tips for cleaning out a gas tank, but when it came right down to what worked best is this: Fill er up with apple cider vinegar and let it sit for a few days. It has to be apple cider vinegar, not white. Don't ask me why. I don't know. Shaking the nuts and bolts and other things got most of the build-up loose. After the vinegar treatment, I power-washed the inside with a little dawn dish soap. Dried it out and sprayed some Sta-bil fogging oil inside and will let it sit until I get around to doing the Ace 100. Thanks to all for the suggestions. JackM

[relic]

Cider vinegar has the highest acid content of all vinegars so I think that's why it works the best. I've used your method on a few tanks with good results. I find the hottest water you can get to rinse after helps too. My only difference is I use a length of chain rather than the nuts and bolts. Ever since I found a bolt in a tank I bought. Guess the p.o. didn't count. The chain does the same job and there's no chance of leaving some of it behind.
Ken

[JackM]

I agree, Ken. I used 3 short pieces of small chain on one I did a while back. Just didn't have any on hand this time. Easy to fish out with a magnet too. The cider vinegar does work well, for sure.

[MTrat]

The electrolysis method sure takes out initial rust well...

[taber hodaka]

Jack every time I put a magnet into a metal gas tank the magnet just clanks to the steel. I think the magnet only works on plastic tanks?? ---------Clarence

[Bill2001]

Use a magnetic pickup wand.