Drill holes in the plastic along the guide lines so your blade has places to start and stop easily.
How to shape abs plastic sheet.
Depending on how deformed your part was originally you may need to repeat the process two or three times slowly bringing the abs back into its proper shape a little more each time.
A common and safe method of reshaping abs plastic is to use boiling water which reduces risks involved with accidentally overheating abs.
Use a plastic cutting knife to cut the sheet down to the general overall size.
Measure the size of the of the overall piece you need.
This will act as a guideline and will help you achieve the shape you are.
Make sure the sheet is just big enough for the form.
Dipping the abs into a bath of cool water will help quickly lower its temperature so it will hold its new shape.
Make several scores along the guideline.
Make straight relief cuts from the outside of the plastic to the curves.
Water boils at 212 degrees fahrenheit at which point abs becomes soft and rubbery but will not burn.
Then mark the cutting line with a highlighter.
Using a plastic cutter prepare the work surface and lay the plastic on it.