Prep for paint

You may remember last summer I purchased a steel interstate tank and side covers from India on eBay. A few other members have also purchased a tank from the same vendor (rsvintageparts2014). The tank is bare metal except for the underside that has a grey primer sprayed on it. Not knowing what type of chemical composition the primer is do you think it is best to remove it and start from scratch for new primer and paint? The side covers I purchased also had a grey primer on them but I have sandblasted them back to bare metal. If any members who also purchased their tank from the same vendor can let me know what prep they have done on the tank before paint would surely be appreciated. Thanks.

I bought one of those tanks.

I had issues with the paint that I used so I painted and stripped the tank twice because I didn't follow directions on the labels of the cans, but once I did read and follow directions everything worked out fine. Todays modern paints have odd recoat window times compared to the lacquers that I have sprayed for 40 years... It took me a while to realize that modern paint is different. Recoat windows are very important with these paints. Usually they say something like "within 1 hour OR after 48 hours" which means if you try to recoat after the first hour or before it dries for 48 hours the first coat will wrinkle and lift, rather than let the next coat lay down on top of it... so pay attention to the directions for whatever paint you chose. (don't be stupid, like me...)

I stripped the tank, washed it with brake clean, lightly sanded it with 220 to give it some tooth, then used rustoleum gray primer/filler as my primer. I followed it up with a few coats of rustoleum black gloss. I applied the norton logo with a stencil I bought from Oldbritts, I masked the pinstripes out and used gold rustoleum automotive paint for them both. I scuffed the painted tank with 1000 grit to give it some tooth for the clear coat to grab onto. I bought a spray can of Eastwood 2K catylized clear gloss which is impervious to fuel and topcoated the tank and side covers without any problems of paint compatibility. I used all rattle cans to spray the paint, because I didn't want to use automotive paint in any of my spray equipment, nor did I want to buy a gallon of expensive high tech automotive paint for just a tank and side covers. It came out,..... "OK" . I have one tiny sag on the tank and a little more orange peel in a few spots where I didn't load it up enough to risk burning through the black coats trying to rub it out.

I think the tank is OK. Fit the cap first before you do the finish. My filler neck is kind of low so the flip top nearly hits the paint when I open it. Also the hole for the roll pin for the filler cap pivot was sloppy and way too large. I ended up going to the next larger size roll pin and drilling out the filler cap to that size so the cap wouldn't wobble around...

here's the tank. I've been using it. It doesn't leak and seems ok so far...

I have no experience with the India built steel tank, but I do have 40 years of experience in paint and coatings formulation with BASF and PPG. I would strongly suggest stripping to bare metal and starting with a good epoxy primer on bare metal. A somewhat less desirable start would be to spray epoxy primer over what ever coating the tank came with. The epoxy should seal the existing coating and provide a good base for bodywork. If body filler is needed it can be applied to the epoxy primed steel. A good urethane filler/primer can also be used to smooth small imperfections.