Rhonn,
If you are wanting to make project boxes with ABS plastic, I came across a website a few years ago on this. I do not recall where it was, but the method was to use a large "oven bag" like what is used for cooking. These can withstand a lot of heat. Then you make a replica of your project case out of wood, etc. and put it in the bag. You put it on a plate you have made with lots of holes and attach vacuum such as a vacuum cleaner to the other side of the plate. This is similar to a vacuum table used for graphic arts, except it is in the bag. With the vacuum on the one side, you use a heat gun or hair dryer to heat up the sheet of plastic through the bag. The vacuum pulls the softened plastic over the mold and shapes it to your design.
Hope I have explained it well enough. I will look around to see if I can find the site.
MP