Another newbie question. My truck has sat with fuel in the tank for the past 7 or 8 years, according to the PO. There is still a small amount (guessing a gallon or two) of liquid in the tank, no longer smells like gasoline. I'm guessing that there is some varnish, sludge, rust, etc, in the tank, and thinking a good cleaning followed by sealing is in order.

Anyone have recommendations on doing this and/or products that do a good job? I've heard good things about POR-15 products, and see they have a gas tank kit with cleaners and sealer.

Thanks,

Duane.

 

dwschmidt, common problem, por-15 kit works real well IF you follow directions! you MUST get all varnish out of tank or truck will constantly shut down from clogging in fuel system. this means fuel pump, carb, and lines should be opened up and cleaned . biggest problem with tanks is rust in 4" depression on bottom where fuel exits tank. once cleaned, do thorough exam of this area, tapping with SMALL ball peen hammer and SMALL pick usually shows issues. DON'T beat the #*#*? out of it and you'll be ok. make sure tank is dry and at room temp before sealing. good luck. pete

 

Took mine to a local Radiator Shop that chemically cleaned the tank and applied a sealer to the inside.

 

took my 1st tank to rad shop, chem cleaned, sealed, lasted a few years but wasn't best job. depression around bung rusted out even being sealed. used steel shot(#4), shook the living #*#* out of it, flushed out with a couple gallons of gas, 1 gal at a time, fixed rust then painted and installed. seemed that sealer broke down with new fuel compounds so did not seal. use marvel mystery oil in every tank. keeps things clean and lubed.

 

This is one of those questions that comes up regularly. Try doing a search on this forum for many discussions of the various materials and cleaning methods. My prefered sealant is generically called "fuel tank slushing compound" that I purchase from private aircraft maintainance facilities located at most larger airports, check your phone book.
This sealant is FAA approved for use in airplanes, if it's good enough for airplanes, it's good enough for me, the FAA frowns on airplanes dropping out of the sky from leaking or plugged gas tanks. A quart should be plenty for an average sized gas tank. Make sure you plug the pickup before treating, the compound will seal it up as well.

 

Peteyshoes, thanks for the tips if using POR-15.
AXracer, thanks for the suggestion for aircraft products-I'll check into that and will search older threads on this forum as well.
fking1, appreciate the thought, but I think I'll try it myself.

Duane.

 

Another source for the slushing compound are motorcycle shops that do choppers, they use it to seal custom gas tanks. Eastwood also sells it, but at a high price. Gasoline has a much lower surface tension than water, so a tank that will not leak water can still weep gasoline.
Here's my cleaning method: (In Buffalo where I grew up, salt induced rust out was a problem not only with body metal but also gas tanks, so I repaired more of them than I care to remember)
1. drain and remove tank. 2. Remove sending unit and pickup or outlet fitting. Make a temporary blockoff plate for sending unit hole and plug pickup fitting if separate.
3. Put in a couple gallons of water, a good handful of clean good sized nuts and bolts and a piece of chain if available. Add a cup of Tide laundry detergent and a 1/2 cup of sodium acid sulfate (available in the swimming pool chem section of your local DIY store or Wally World where it will be labled as ph DOWN additive). Cap off the fill neck with a household rubber glove and hose clamp. Slosh and shake the tank vigorously in all positions so the parts inside can scrub off all the rust and residue. Pour out the slop, rinse with water, and repeat until the rinse water comes out perfectly clean. Rinse once more with hot water and 1/2 cup of baking soda, then with clear hot water. Pour in 1/2 gal of denatured alcohol (look with the paint thinners for shellac thinner or camp stove fuel if you can't find it labled denatured alcohol) Slosh it around and pour out to absorb and remove any water. Open all openings, air dry then check inside with a strong light. If it is good and clean, immediately treat the inside with the slushing compound. Do not leave the tank untreated after cleaning, rust will start reforming in a matter of hours. Follow the directions on the slushing compound can. Basically you dump it in, slosh it all around to coat the entire interior of the tank then dump out the excess. Allow to dry and you are done.

 

The pour 15 system works very well but is a ton of work .I used it and have no problems .Follow instructions to the letter .

 

The problem with the 53-55 tanks is they are internally baffled. Makes it harder to get it them fully cleaned and coated.

 

When I used to race motorcycles, we would always treat the tanks with a product called KREAM. It was a three step process where you would drain the tank and flush it with soap (Dawn Dishwashing Liquid) and water. Then there was an acid that smelled very much like Naval Jelly that you put in the tank to eat and neutralize the rust. With that finished, you washed the tank again with Dawn and Water then post washed with denatured alcohol. The final step was the KREAM which was actually pignented white shellac. You rolled the tank around with a bunch of this shellac in it and it sealed up everything. Shellac is impervious to gas and seals the tank with a glass hard liner. BUT, you have to get rid of the old varnish and rust first with the acid.

If this was done patiently and correctly, the tank would never rust out again. So, it sounds like the radiator shop chem wash thing would be good, then do the shellac (in the process above, the denatured alcohol is used to absorb any moisture in the tank) One other important thing to remeber is you can't let the tank sit and get dry enough to flash rust inside. You need to do these things all at once.

PS Just got AXracers post- sound like the same process, his had more in depth info - smart guy!

 

I just steamed out my aluminum boat tank 2 days ago-40 gallon aluminum with a baffle. Used my propane fired lobster/clam cooker stand (we do have both here on the coast of Maine!), an old 5 gallon steel fuel can with a 4 foot piece of 1 inch high quality rubber marine exhaust tube inserted into the fuel gage hole with the tank upside down. Steamed for about an hour, came out really clean with no fuel order. The fuel tank goes in my wooden boat and I had my steam box etc out since I had to steam bend a plank for the transom. Boats happens to be another hobby that I enjoy.

 

Thanks all for the additional suggestions. I'm probably going to use the POR-15 kit (includes cleaners and sealer), and add the nuts/bolts/chain at the cleaning stage. And use the alcohol trick to help remove water.

All I need is time to do it!

Duane.