Plastic balls and Acetone for plastic repairing

[Chuck Step-a-side]

I read about someone using plastic balls and acetone to repair his door panel. I have major cracks on my AC molding box that's located on the firewall and it was repaired by everyone favorite go-to fit all - DUCT TAPE! That make me cringe!!
Back to the plastic ball questions. What type of plastic and where do you get them; and what is the procedure. Thanks

[VileZambonie]

Your best bet is to get one from a donor if you want it to look right. If you want the pellets just look on eBay

[80Chevy4x4]

I used the ABS Plastic Pellets to repair around where the radio inserts because the previous owner butchered it up....it worked pretty good...I am still in the process of finishing it.

[Chuck Step-a-side]

I was checking out AC molding box today and I agree finding a donor would be the best option. Thank again!!