Firestone gas tank

[dchris]

A feind gave me a 194? 3.6HP firestone motor. The gas tankl is full of grundge. The outside of the tank appears to be solid, but the inside is rusty looking and has loose particles. What is the best way to clean a small tank out?

[ohm116]

Remove the tank from the motor and let it dry out. Once it is all dried out you can use something like aquarium gravel or small nuts and bolts to scour out the rust. Put a handful in the tank and seal it up. Start shaking the gravel well act like an abrasive and scour out the rust. I usually shake it around for five minutes and then over an empty garbage can turn it over and start shaking the gravel back out, this is the most annoying step in the process Once you can no longer hear gravel bouncing around in the tank turn it upright and whack all around the outside of the tank to make sure that no bits of gravel have gotten stuck. Rinse the tank out with water and let it dry completely. Repeat the above process until the tank is sufficiently clean and then install an inline filter to catch anything you missed. I have done this successfully on a few motorcycle tanks and it is pretty effective. I'm sure there is a chemical you can use that would work as well but I like this method as it is relatively clean and cheap.

[F_R]

Dump in a bottle of plain ol' isopropyl rubbing alcohol (from the grocery store) along with the handfull of steel nuts. The alcohol will cut the rotten gas gum and the nuts will knock the rust loose. Then water will wash it all away. I'd say that probably 90% of Scott-Firestone motors have rusty tanks.

[tmcalavy]

If you want to seal it after you clean it, there is an aircraft-rated tank sealer on the Web...can't remember the name. It's rated to withstand alcohol and gas fuels. It's not the motorcycle tank sealers like POR or KREEM, but another name...I'll check the shop tomorrow and see if I can find the can/name and post back. It puts a thin skim coat/seal inside the tank. An inline fuel filter is a must for older outboards.

[ohm116]

That's a good point with the alcohol, I well have to swish my Gales tank out with that as it does have some stains in it from the old gas, no rust being an aluminum tank though. I need to find a set of barbed fittings for it as well, any ideas on what the threads are?

[dchris]

The alcohol and nut/bolt mix has been working well. My mix is getting cleaner each time I have done this. The next problem I noticed is pin hole air leaks while drying the tank with compressed air. They are along the top of the tank. I am going to the local auto store to look for internal tank sealers. I don't want to add anything to the outside if posible, but I can't live with a gas leak. Has anyone had any experience with tank sealers?

[F_R]

I have used Kreem. It comes in a kit and instructions must be followed to the letter. J.C. Whitney sells it.