Farm Fuel Tank

[Pat]

Gary, Either I forgot or didn't know you were an aeromodler. I have scratch built my own designs for U-control, free flight, RC powered and soaring as well as kits. Haven't flown any for a while. Started before digiprop was available back in the super regen rcvr days of a single gas tube rcvr and wind up rubber band escapements. "The good old days" when a chiropracters diathermy machine or a CB transmission could "spin you in" as our equipment was in the 27 meg band.

Note to the thread police: powered model aircraft use fuel tanks which after receiving crash damage sometimes need repair. Usually light sheet metal work and soldering.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

I would highly highly suggest to spend the money and buy a new tank. I have seen more vehicles and tractor injectors ruined by old tanks, even ones that have been cleaned and reconditioned. And use double filtration on any tank that you use. If there is any rust in that tank at all it will only continue.

[GaryM]

Pat,

I only flew electric powered A/C and Sailplanes, with no fuel tanks, so I can't discuss them in this thread. [img]/forums/images/icons/mad.gif[/img]

[egon]

Very good advice. !

You pays me now or you pay me later but I will get paid! [img]/forums/images/icons/grin.gif[/img]

Egon

[Pat]

You have received some well intentioned advice however, if the tank is tapped and found not soft or nearly rusted through and it is coated internally with CREME or equivalent, there will NEVER be any rust in contact with the fuel in the tank...PERIOD. The double filtration advice is not bad but a single good filter (I prefer water absorbing elements) is sufficient. Multiple filters (of the same type) are not an improvement as the first filter stops anything the subsequent filters would stop. The typical failure mode of a filter is cloging up and restricting flow, not passing contamination. This is especially true with gravity feed but if you have a high pressure pump you could rupture a filter and pump junk into your vehicle.

Where a multiple filter solution is quite good is with the Fram or similar double filtration system where the first filter is a water coalessor and larger particle filter and the second filter removes the droplets coalessed by the first filter and finer particulate contamination. These work well with low pressure pumps as well as with gravity systems and patience. They are available to be used in a single filter body as a two stage filter or as separate filters for adjacent filter bodies. They can be purchased in varying "micron" sizes with the finer filters doing an incredible job but subject to plugging easier than the "standard" porosity filters. You pays your money and takes your choice.

There are ultrasonic gauges that will allow you to measure the thickness of the sound steel in the walls of the tank. This will allow you to easily measure the percent of the tanks thickness remaining in any problem areas. As long as the tank is relatively sound structurally, a plastic inner coating will totally prevent rust to fuel contact and leaks. The ultrasonic gauge will automatically NOT MEASURE THE THICKNESS OF ANY RUST.

Sure you should be cautious regarding the bottom of the tank, especially if it was a diesel or gasoline tank as water is heavier and would accumulate at the bottom. However, it is also very important to check the top of the tank as that is where condensation forms in the air space of the tank and can be a source of premature failure.

Pat [img]/forums/images/icons/smile.gif[/img]

[Adron]

Just my 2 cents worth, but I have have very good luck by using Electrolysis to remove rust from tanks. Even some tanks that in very poor shape. A synopsis of the procedure can be found at:
Rust Removal by Electrolysis. Just turn the proceedure around and after all the pinholes are repaired, fill the tank with the soda solution, attach the negative (-) lead to the tank. Isolate the positive lead so it can't touch the metal tank. Place the sacificial anode in the solution, attach the positive (+) lead. Turn the battery on and let it cook.

The last poor tank I used this process on was 60 gallons, and I let it brew for about 18 hours. Everything went down to solid metal, and it developed a few more pin holes, but it worked.

[Pat]

Adron, Rust removal by electrolysis is such an underutilized technique. It has a great area of beneficial application but gets ignored most of the time, for being non-traditional I suppose.

I worked up a reverse plating process once for passivating stainless steel. Whenever stainless is cut or welded you can disturb the alloy and end up with some available iron at the surface which will rust and discolor the stainless. By reverse plating the iron from the surface you prevent this. Imersion of some object in a plating bath is not always convenient so I "borrowed" an electric brush plating technique for reverse plating the iron from a stainless steel surface.

Once the rusting of a tank is halted, even if there are pinholes, Creme or similar product will plastic coat the inside and the fuel will not contact the tank. There are good paints that will go on over light rust and chemically convert it to a passive substance (iron phosphate?). These paints will prevent subsequent rust. They may not be specified for imersion in fuel but if the tank is coated with plastic such as with the Creme product the fuel will ot contact the painted surface.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]