scribing acrylic

SCRIBING AND BREAKING CHEMCAST® GP

Straight cuts in 1/4" or thinner sheets of Chemcast® GP acrylic plastic can be made by scribing with a special Chemcast® GP cutting tool available at Chemcast® GP distributorss. Scribing is effective when the quantity of Chemcast® GP to be cut is limited since it requires very little outlay for tools. Neither thick sections nor patterned sheets of Chemcast® GP can be cut by this method, however.

Using a straight edge as a guide, the point of the cutting tool is placed at the edge of the material and drawn the full width of the material while applying firm pressure. This is repeated 5 to 6 times for thicknesses up to 3/16" and 7 to 10 times for ¼" thick material. The scribed line is then positioned face up over a 3/4" diameter wood dowel running the length of the intended break. The sheet is held with one hand and downward pressure applied with the other hand on the short side of the break. The hands should be kept adjacent to one another and successively repositioned about 2" behind the break as it progresses along the scribed line.

SCRAPING EDGES OF CHEMCAST® GP

After cutting the Chemcast® GP sheet, it is often desirable to scrape the edges. Scraping serves two purposes. It removes any nicks or burrs which may form a notch to weaken the Chemcast® GP, and it improves the appearance of the edge.

A suitable scraping tool may be made from a piece of power hacksaw blade or heavy duty steel with one edge ground to a sharp 90 degree corner. The tool should not have a knife edge. The cutting tool used for scribing has a builtin scraping edge.

The Chemcast® GP part should be held firmly in a vise or holding fixture. The scraping tool is placed at the far end of the cut and drawn toward the operator. Firm, steady pressure should be used throughout the scraping operation. Care must be taken to keep the cut edge square.