Fuel System: How to clean and get gas tank ready for use?

[StarDiero75]

Howdy guys,

I got a 61 Lark OHV 6 that I'm resurrecting and I want to get it to where i can use the gas tank. Currently I've been running it out of a gas can on the side of the car but I want to get the gas tank cleaned out and back in it.

When i dropped it a little while ago, i washed it out with the hose as the gas that was in it was 16 years old, nasty stuff but great weed killer lol. I later placed it in the sun and let it dry out. It had all sorts of crap in it and I want to be sure i got it all out, how should i go about finishing the job and getting it back in the car?

Thanks,
Ryan

[DieselJim]

I cleaned an old,23, Chev tank. Used 3 cans of draino. Filled the tank with hot water. Put a hot water element with a 110 v plug. Let it cook all night. Emptied tank. Stuff is great weed, grass killer. Pressured washed out. Tank was clean and had many pin holes.

[GrumpyOne]

I cleaned an old,23, Chev tank. Used 3 cans of draino. Filled the tank with hot water. Put a hot water element with a 110 v plug. Let it cook all night. Emptied tank. Stuff is great weed, grass killer. Pressured washed out. Tank was clean and had many pin holes.

That sounds like a winner and pin holes should come as no surprise.

After the tank is clean and dry, locate all the pin holes from the outside and fill 'em with a high quality filler such as Devcon's titanium putty and let it dry overnight. I'm assuming that the structure is good in general.

Fill the tank with water once again to see if you overlooked any holes and and repeat the filling with putty until they are all plugged. Once again, empty the tank and dry it thoroughly.

I recommend coating the inside with Red Kote on just the bottom 1/8 of the tank.

I did this on my Power Hawk and it worked great!

[TWChamp]

When I removed the flaking tank coating someone put in my 50 Champion tank, I used a couple quarts of E-85 and a couple handfuls of lag bolts and wood screws. I mounted the tank at 45* and kept rotating it for about an hour, then tuned the tank over and did the same to the top side. Now the inside of the tank looks like NOS.

[tim333]

Search one of my old threads where I detail how to clean a tank using water, baking soda and a battery charger. Or PM me for my phone number and I’ll explain it to you.

[TWChamp]

Search one of my old threads where I detail how to clean a tank using water, baking soda and a battery charger. Or PM me for my phone number and I’ll explain it to you.

I used that method to derust a badly pitted Cub Cadet wheel, where someone used calcium chloride for weight.
It works great, but I used WASHING soda, not baking soda. I bought it in the grocery store.

[tim333]

Both work.

[Jeffry Cassel]

OK, I think this is gonna work. Last summer I cut a hole in the top of a gas tank 1" smaller than a sheet of stiff paper. This allowed me to get inside and really, really clean up the inside. Amazing amount of crud and rust in there. After cleaning I wiped it down with laquer reducer and covered every square inch with Northern tank sealer. You're going to miss spots if you dump it in and slosh it around. I cut a piece out of a junk tank the size of a sheet of paper, flanged the hole and put about 40 screws in it sealing it with tank sealer. Don't get metal filings in the nice clean tank. I used a cut off tool. Be sure there are no fumes in the tank before cutting-don't blow yourself up. If tank was recently in use, completely fill it with water and drain before cutting. I do not think it will leak

[TWChamp]

What's in the tank that needs to be cleaned out?
Old gas, tank sealer, or rust?
I haven't tried MARINE CLEAN, but have heard lots of good about it.

[Jeffry Cassel]

If your tank is clean there'd be no reason to clean it. It is amazing the crud in a 60 yr. old tank that has been sitting for 40 yrs. Rust, dirt, varnish, bugs. Marine clean is a super good detergent; they recommend it for degreasing rusty metal to prep it for POR. I've used it and it is a good product. Don't think it'd be much good for cleaning a gas tank, tho. I've been told drain cleaner is good for cleaning out gas tanks.

[StarDiero75]

Thanks for all the tricks guys!

Last i saw, i had all sorts of garbage coming out of it. It looked like a little rust, muck, gas, everything. I'm gonna start back in on it during Thanksgiving break from school.

I'm very intrigued about the baking soda and a battery charger, ill give him a PM. Otherwise I think draino and gravel it is

After i do that, can i just slap it back in or should i do some sort of sealer in it?

Thanks a lot,
Ryan

[TWChamp]

I would never seal a tank, even though some have had success. Who knows what kind of gas we'll have to use in the future, and it may strip the sealer off. Rather than rocks, I used lag bolts and wood screws, as the sharp edges removed the tank liner better than the smooth surface of rocks could do.

[DieselJim]

I would never seal a tank, even though some have had success. Who knows what kind of gas we'll have to use in the future, and it may strip the sealer off. Rather than rocks, I used lag bolts and wood screws, as the sharp edges removed the tank liner better than the smooth surface of rocks could do.

And you can get the screws out with a magnet as long as they are not brass.

[TWChamp]

And you can get the screws out with a magnet as long as they are not brass.

Yes, and I should have mentioned that I made a plate to cover the hole for the sending unit.

[StarDiero75]

Alright I'll use wood screws then.
Thanks a lot guys! I'll let you all know how it goes come break.