Hello Iyyer sir, Plast-aid is a two-part acrylic plastic that can be used to repair and make all sorts of things. When mixed, the powder and liquid produces a strong, hard, durable, waterproof plastic in about 15 minutes, that can be sanded and painted easily. Unlike epoxy, the curing time is very less, and the material doesn't become brittle or shoe cracks overtime as Araldite does. Primarily used in automotive repairs and as a binder for filler before sanding and painting.
https://www.plast-aid.com/Plastex is another marketing name for the same item I guess.