Farmall Cub

Greetings, all. I hope you are well and safe.

I'm having fuel problems with my 130 and need to clean the fuel tank. Several posts mention using muriatic acid to dissolve the rust, and I'm wondering if I can use the 31.45% muriatic acid used for swimming pools. Otherwise, I need a suggestion about what to buy and where I might find it.

Also, if someone can tell me where I might find RedKote and how that is applied. (Figured that out.)

Lastly, I'm considering skipping the full cleaning and installing an in-line filter between the sediment bowl and the carburetor. Have you done that with reasonably long-term success? (It would be the quicker and cheaper option, obviously.)

Many thanks in advance for your always wise advice.

Chris

My experience is in the motorcycle world. I don't think the in-line filter is a good solution.

As far as cleaning the tank I've always used phosphoric acid. Home Depot sells it in a gallon bottle in the paint section (it's called Kleen-Strip, I believe). I've diluted it different amounts depending on how rusty the tank was and how big of a hurry I was in. Scientific Wild-Assed Guess for your 130 would be 2 gallons and the rest warm water. Will probably take several days. Once the acid is depleted it will stop working. If you still have rust after a few days repeat the treatment.

Don't use the fuel valve to close off the bottom of the tank, the acid tears through pot metal. I suspect the same will be true if you use muriatic acid.

After cleaning you need to rinse it thoroughly. If you don't want it to flash rust you need to rinse out the rinse water with lacquer thinner.

I always used Caswell epoxy liner. They actually specify it adhered better if the tank had rust that wasn't loose in it. I always went to a lot of trouble to not have the tanks flash rust because I was getting paid a lot of money to do them and motorcycle people can be very picky about appearances. If I were doing my own I would go ahead and let it flash rust after cleaning and then epoxy line it.

I personally do not like working with that stuff.

I sent a cub tank that had some pinholes to a radiator shop. They cleaned it patched the holes and coated the tank pick up and delivery $300.00

I use it a lot, pick it up at ace hardware, be careful it works and burns, flush with baking soda and water when done, pull the filter and use a plug in place of it, spray some penetrating oil in it when done as it is clean metal and will rust fast

This is old tractor guy / farmer method that I was told. Mind you I'm not suggesting you use this method, but I used it years ago and it worked.

Remove tank, remove fuel shut off, plug hole where shut off was. Place tank in back of your truck. Fill tank half with water, add clean gravel (I used fish tank gravel). Drive around as you normally would for a week. Drain water and all gravel from tank. Thoroughly dry tank with air. Reinstall fuel shut off.

Again I'm not suggesting anyone use this method, but I have had success with it. Inside of tank was squeaky clean.

ctltmp wrote:Remove tank, remove fuel shut off, plug hole where shut off was. Place tank in back of your truck. Fill tank half with water, add clean gravel (I used fish tank gravel). Drive around as you normally would for a week. Drain water and all gravel from tank. Thoroughly dry tank with air. Reinstall fuel shut off.

Sounds like using it to polish rocks as a tumbler!

Opinion: It seems to me if the problem is the rust, removal of the rust is the best method. Coating after rust removal helps keep the problem from resurfacing.
I run a fuel filter (gravity style metal can type) between the separator and the carb, but do not have a rusty tank. If you pick the right fuel filter, it does work, but also is another maintenance item that must be replaced occasionally. The fuel filter also makes it very difficult to use a metal fuel line. If you choose to use a rubber fuel line, there are some safety and maintenance considerations. The rubber fuel line must be replaced occasionally and is more susceptible to leaks and cracks than a metal line.

Thank you all for the advice. I have the tank off and valve removed, so I think I will go ahead and try to remove the rust. Wish me luck!

Something none of us have mentioned:

You should get any loose rust out first. Soapy water, a hand full of small nuts, agitate. Count the nuts first so you know when you've got them all out.

Also, a rinse with lacquer thinner to wash away any fuel or varnish. They'll keep the acid from getting to the rust.

I'm having the same issue, ill have to try the lacquer thinner. I've used everything else and its getting close but still some rust in tank.

Have you tried using steel shot / ball bearing or light chain and oil AND driving around with the tank in your trunk or the bed of a pickup. I have seen video of people jacking up a tractor and stapping a cub tank to the rear wheel and letting it run for an hour.

Several years ago I used muratic acid and small pea gravel on my 55 cub tank and ran the tire slow for a couple hours. Then emptied and flushed. After a couple days drying I redcoated it and its still fine today. Most people don't have access to a backhoe so you'll have to improvise and do it safely.


Rick

One thing that needs to be said in this is to be sure that Muratic acid does not come in contact with aluminum. I made that mistake once...