Sealing gas tank

I started working on the gas tank today. It didn’t look too bad when I started, but ended up taking a LOT more work than I imagined.

Step 1: Remove tank from Jeep.

Step 2: Drain tank into a 5 gallon bucket. A lot of sediment came out of the tank, but it still looked fairly clean and rust free. I could tell that there was rust on the top side and filler neck of the tank.

Step 3: Clean the tank. The KBS kit came with KBS Klean – a concentrated cleaner that you mix 1:1 with hot water. The directions said to use it all, but I did half of the bottle, which came out to 1/2 gallon once mixed.

I taped up the openings with actual DUCT TAPE, not Duck Tape that you buy at WalMart. Once sealed up, you pour it in and add a bunch of nuts and bolts to help break the stubborn rust away from the tank. Then you tape up the filler neck.

Now the fun part begins! Once the cleaner is in, you have to shake and rotate and turn the tank, making sure you cover all surfaces of the tank. I worked on one part at a time – side, end, side, end, bottom, top and filler neck. I rotated for a good 2-3 minutes, then set it down for about 5 minutes – then I repeated the above process. I did this for a little over 30 minutes. Then I dumped it out (it’s biodegradable) and rinsed until the water came out clean. This is the result after the first cleaning:

A little better, but not much! The gas smell was almost gone. Some of the varnish was gone. BTW, if you are planning on doing this and NOT repainting the tank – FORGET IT! This cleaner removes paint!

I mixed up the other half of the cleaner and repeated the process. This time I spent about 45 minutes and made sure I did more with the top of the tank and filler neck. When I opened it up and washed it out, it was noticeably cleaner. This time I dried out the inside with a rag and used my shop vac to blow air into the tank to dry it. I also used my air compressor to blow air at the seams which hold water.

 

Between rotations, I worked on the pickup plate and fuel sender.

Once the tank was dry, I taped up the openings again and added the whole bottle of KBS Rust Blast – FULL STRENGTH and taped up the filler neck. This stuff is a rust remover, metal etcher and leaves a zinc phosphate finish. This finish will protect the tank from rust for 10 days (according to the instructions) to 30 days (according to the bottle).

Once in the tank, you will rotate the tank to cover all surfaces, then let it sit on one surface for 5 minutes (don’t let it dry out), rotate, let it sit on another side, rotate. Repeat until all surfaces are covered for a MINIMUM of 30 minutes, MAXIMUM 1 hour. Drain it out into a container for future use. Once it’s drained out, rinse it out a few times and dry it again. The shop vac works great for this – just use compressed air to blow the air out of the seams – the tank has to be completely dry before you seal it! Once dry, the KBS Blast leaves a slight powdery finish on the inside. The instructions say this is normal and won’t affect the sealer.

While the tank was drying, I used the leftover Blast to brush on the sender, gas cap and pickup plate rust. After keeping it wet for a half hour, I rinsed and dried those parts also.

Tomorrow afternoon I will do the sealing. I didn’t want to start it late this afternoon. I won’t lie, this is a labor intensive job! I started at 12:30PM and finished the etching at 4:45PM! The sealing process SHOULDN’T take too long – mix it, pour it in, tape the openings, rotate to cover all surfaces, drain well and make sure all bolt holes are cleaned of sealer before it sets up. Then you have to let it sit and dry for 3-4 days before you use it. I am going to brush the sealer on the pickup plate, sender and gas cap.

Again, plan on sanding and repainting the outside of the tank when you are finished.