Smoothing and shaping interior plastic

[ChuckstrPT]

So I'm hacking up my overhead console to fit my CB into it...cutting with an air recip saw, and die grinder with a small cut off wheel. I think I've just about got it in there, fairly cleanly, Except....that saw and cut off wheel gets the plastic so hot, I got some melty stuff, and generally not smooth edges. I'd like to keep the interior looking presentable. Any suggestions on smoothing and shaping the plastic? Can I just use a sand paper drum in the dremel/die grinder? Hand sanding? what grit? Or file? I'm sure there are some master fabbers out there. Steer me in the best, fastest direction!
Thanks!

 

[Thayer]

I'm no expert, but when I use to cut polycarb or delrin on the end mills at school, the old timer machine shop workers would tell me to use Windex as a coolant to avoid melting.

Another thing I would try is using a little bit that Dremel sells to cut metal. It looks a lot like a tiny end mill cutter bit and cost me about $5 at Walmart. I think it's intended to cut holes in sinks, but it cuts cleanly through almost everything I've tried.

 

[What Rd]

A good old fahioned fine tooth file does wonders. It will remove the plastic much faster than you'd think and you can get nice, clean finished edges. I make an opening using the dremel and then do the finish work with the hand file. The sanding drum on the Dremel still turns fast enough on the lowest speed setting to melt the plastic a bit. It's much easier to control a hand file and if you get a square or triangular section file you can get nicely all the way into 90* corners.

 

[ChuckstrPT]

A good old fahioned fine tooth file does wonders. It will remove the plastic much faster than you'd think and you can get nice, clean finished edges. I make an opening using the dremel and then do the finish work with the hand file. The sanding drum on the Dremel still turns fast enough on the lowest speed setting to melt the plastic a bit. It's much easier to control a hand file and if you get a square or triangular section file you can get nicely all the way into 90* corners.

Thanks! That was what I was thinking. Power it great for speed, but I think anything power will create too much heat. I've got some wood files in the garage. We'll give that a try! :wave:

 

[old_man]

The trick to get it looking nice is to cut it so that you do not come up to the line. Then you file and sand it to the final dimensions. A wood coping saw can cut irregular shapes with some control