Acetone not working on ABS?

[cruzer]

I'm trying to fill this hole, and it's half ABS on the underside but the top is coated, and the stuff won't dissolve with acetone even after 48 hours in the jar
I have some scraps of what you see, tried to make slurry so i can fill this hole, sand, cut it and spray it, but it wouldn't dissolve
i'm thinking about getting some plain abs scrap which should dissolve, fill this whole and cut it
i would be using a cnc to cut it

Suggestions?

[img]http://i.imgur.com/6DtcuER.jpg[/img]

[IMBoring25]

Do you also have raw filament? I once had a print that cracked a little too much for its application and just held the part under the hot end and turned the extruder drive manually to fill the cracks...Basically the same thing as those 3D printing pens you see but more improvisational.