I got a good result cleaning up my kdx tank.
I started with an unloved tank. All the crud has helped protect this tank from UV damage.
I scrubbed the tank with fine steel wool and hot soapy water to remove the crud.
l scraped the tank with a half a pair of scissors. l find them easier to hold and use than a blade.
I wet sanded with an orbital sander 360 than 800. l found that the sander didn't level all the scrape marks so l had to use a rubber rubbing block to get the tank surface flat again. Wet 360 than 800 again. It didn't take long to sand the high points off. I've not wet sanded over 1200 but some people will go to 2000.
The buffing.
Wool buff pad and lots of the polishing compound. l was conscious of burning/ melting the plastic so l kept the pressure light.
Different pad for the polish, lots of polish and low pressure.
Another clean pad for the final polish. I tried a foam pad but it didn't work as well as the wool pad.
Total time investment for this tank was around 13 hours. There is some fuel staining low on the tank but it is a 33 year old tank.