The gas tank had waited in the chicken coop for two years. That was long enough to take on a couple of boarders — mice who built a nice soft nest behind an inside baffle. In spite of the fact that the gas tank was bone dry from the first day we got the car, I know that mice hadn't invaded until we took possession. The nest I pulled out piece by piece and sucked out with my shop vacuum was made of our brand of paper towel and a cotton swab or two that had been lying around. I had to use some wire to fish out the little bits. Time to set more traps, I guess.

I glanced inside the tank when we put it into storage, and I recall thinking that it was pretty rusty, though I was also happy that the tank was completely empty and had been for some time. Perhaps it is a matter of perspective now, but looking at it after two years of repairing other (worse?) rust made it seem a little better. The rust inside was scary nonetheless. There was a welded repair that had been covered with blue silicone sealer. I recall the previous owner pointing to some blue stuff and saying "Kreem?" but I have to admit that "Kreem" didn't make much sense to me then. Now I know it is a type of gas tank sealer. Our closer look inside the tank showed us that the tank had never before been treated with a gas tank sealer. That fact simplified our work, since we wouldn't have to remove a previous sealer to apply our own.

The underside of the tank, on the corner nearest the threaded hole for the fuel sump, had been repaired by cutting out a rusted area and patching it. The rest of the tank wall was unmolested and solid. The rust repair was probably done at the same time as the "repair" of the fuel sump hole on the trunk floor that we redid. This area of the E-type is commonly rusted, I've heard. It can collect water, since it is in close proximity to a hole fairly near the pavement and since Jaguar apparently used jute pads to soundproof. The jute pads were situated between the gas tank and the floor of the trunk. Unfortunately, they soaked up moisture and eventually promoted rust.

Bottom line: We didn't need to do rust damage repair, though sealing and removal of lesser rust deposits were still needed.

I decided to use POR-15's "US Standard Fuel Tank Sealer" kit. I'd read positive reviews, and I've been overall happy with other POR-15 products I've used. I know that the rust protection coating is mighty tough stuff, and I figured the sealer would be tough, too. Also, I was attracted by the simplicity of buying a kit that included everything I'd need. Cost was in line with what I expected: 50-75 USD. My kit arrived with two quarts of "Marine Clean" detergent, a quart of "Metal Ready" rust converter and metal etcher, a quart of sealer, and a large-ish container of fuel treatment, that I won't use until I actually put gas into the tank. A single letter-sized sheet contains all of the instructions. In short, you clean the tank thoroughly, convert any remaining rust and etch the steel, and then coat with the sealer. (See the sidebar for all the details of our sealing job.)

Since I wanted to make the most out of the detergent that came from POR-15, I decided to do a pre-cleaning of the inside of the tank. There was no sense in pouring in the special detergent to do what regular old "industrial strength" degreaser-detergent would do. To that end, I used a 1:1 dilution of Kirkland brand (yes, it came from Costco) "industrial/commercial" degreaser-detergent. This stuff is colored a flourescent-like green. I've used it to degrease parts and I've even used it — with spotty results — to clean items that were to be zinc plated. It has worked very well to remove grits and greasy deposits. I used the regular degreaser in the same manner that the POR-15 folks recommended using their "Marine Clean" detergent. The first cleaning really took out a lot of junk, both loose chunks of grit and flaked rust and dissolved goo. The detergent mix came out looking like eight-hour old espresso. After a clean water rinse, I redid it. The second batch of detergent came out signficantly more clean, but still definitely brown. The third batch came out virtually the same color as it went in (see the left half of the comparison picture in the sidebar), so I figured that the detergent had done as much as it could.

At that point, I began using the "Marine Clean." Now, "Marine Clean" is a clear liquid, and the POR-15 people claim that it dissolves varnishes and residues that result from oxidizing fuels. Apparently this works in gas lines as well as gas tanks. I actually wasn't expecting the "Marine Clean" to get as much out of the tank as it in fact did, since I'd already cleaned the tank with some also pretty tough detergent. That "Marine Clean" really works — the first 1:1 dilution came out significantly brown, indicating it was at least dissolving what my other detergent couldn't. The second dilution also came out somewhat brown. One thing that was a bit unsual was that the instructions suggested that there was a third application of the "Marine Clean," but my kit contained two quarts of the stuff. I figured that the POR-15 people decided that three was overkill and two would suffice.

The test of the relative strength of a "industrial" degreaser-detergent and the POR-15 "Marine Clean" detergent was really the only surprise in the process of sealing the gas tank. The rest of the process went without much to note.

After the inside was sealed, I painted the outside of the tank. I did decide to mask the areas where the fuel pump and the fuel level sensor attach as well as the threads for the fuel sump. These now are clean metal. I am thinking about installing a different (more dependable?) fuel pump, though I'm not sure what type, submersible or not. That is a question I do not need to answer right now, however.

The inside of the tank now looks like this. The POR-15 instructions say that you can repair larger holes with a fabric-like product and POR-15 sealer applied to the outside of the tank over the holes. Thank goodness we won't need to do that kind of thing!