I went to a local plastics retailer, where you can buy plexi and got a three part solution. Each part is a squirtable solution of different grits and you start with the most gritty and work your way down, buffing with a towel or like. It is a long process but something that can be done watching tv or something. The tank nees to be empty however. It worked great for me and built strong arms, a lot of buffing!!