I purchased a 2006 Rancher 350 2WD in pretty fair shape. It had been serviced regularly but the body plastic and seat had been a little neglected, having only been hosed down after riding in thick swampy terrain. The color was dull and faded but mainly "dry" looking. I decided to try and restore the plastic to bring back the color and maybe get rid of some of the scratches.
There are 2 ways to go about this:
1-- use a boiled linseed oil and paint thinner mix
2 -- use a vinyl floor liquid wax product
Both require the same sanding prep work so it is up to you but this article will concentrate on the #2 process.
Step 1: Remove the Racks and Skid Plates
To be able to work easily on the plastic surfaces, it is advisable to remove the racks and skid plates. My front skid plate was bent and I couldn't get it fixed to suit me so I ordered a new one. Same with the plastic cover on the front push bar. My rack needed a paint job as well. Be sure to note what hardware is used for each rack part and keep it safe.
Step 2: Wash and Dry the ATV
Wash the ATV thoroughly using Dawn dishwashing liquid. Dawn helps remove oils and grease from the surface. Dry the the machine completely.
Step 3: Sanding/stripping & Painting the Racks
Using a steel cup brush and my grinder, I stripped all the rust and paint from the racks. Then I wiped them down with acetone.
I used a spray on bed liner from Rustoleum. It's thick, black, and dries to a nice texture. It took about 3 cans to do the racks. I may also do the wheels later. This stuff looks really nice.
Step 4: Preparing the Plastic
Using fine grit sandpaper, start with the lowest number you have and work up to the highest. Sand until you are satisfied with the results. Keep in mind the finish will look very rough at this point. Don't despair!
Finish off with 0000 steel wool. If you don't have much oxidation or scratches, you can just scuff up the plastic with the super fine grit and the steel wool.
I used a Dremel oscillating tool to sand most the plastic. I had to make my own triangles of the proper sandpaper because I couldn't find any locally. 320 was the finest grit I could find. You can Google how to do that but I advise that you make it early so it will have time for the glue to dry. I used about 4 triangles of the 800 and 1000 grit paper. I also used a sanding block for some areas. For the steel wool, be sure to wear gloves. I was able to use the rectangles of wool to sit under the Dremel so I could still use the power tool.
Step 5: Applying the Wax
I used car wax applicators (foam) to apply the wax. Apply it thinly. You can work on 1 section at a time but since I was applying many, many coats, I worked in a methodical pattern so that by the time I was finished going around the ATV, I was ready to start on the original section for the next coat. Between each coat, I buffed it out by hand. All in all, I believe it applied 7 coats. At this point you should apply a high quality automotive wax and buff it out after it thoroughly dries.
It's been about a year since I did this and I'm still very satisfied with the results however be advised that you will get little white wax flaking up over time. I don't have any pictures of that because the ATV is stored at my family farm where I ride it. I will post some pics as soon as possible.