Removing shallow scratches and scrapes from acrylic is a relatively easy task. Simply use 600 grit wet and dry sandpaper to remove the scratch then polish to a shine using Gel Gloss or other automotive wax/polish with a soft terry-cloth type rag. A shallow scrape looks worse than a deeper knife cut, but is easier to fix simply because scratch removal is mostly concerned with the depth of the scratch, be it a cut, scrape or gouge.

Note there are some issues concerning the depth of the scratch. Acrylic tubs start out as a flat sheet and are stretched over a mold. One can visualize how the thickness of the acrylic will vary on a tub as it stretches down the side walls and around the corners in the bottom, etc. So trying to remove a scratch from a bottom corner is more of a concern than removing a scratch from the top deck area. For this reason, the do-it-yourselfer should only attempt to remove very shallow scratches from the bottom. If a scratch goes through the acrylic, it is not possible to remove it. A professional repair service will be needed to fill and spot the scratch.

Gel Gloss can generally be found in the plumbing sections of the home hardware stores.