How to obtain clean output from Boolean operations?

[mikehoulder]

Hi folks. This is my first post.
I suppose it's to be expected. I'm still in my first few days with AC3D. But I am so *** depressed. I was counting on being able to get clean output from Boolean union and subtraction commands from AC3D. I've spent so many hours and days cleaning drawings by hand using these operations in other programs.

By clean I mean: every polysurface bounds a volume. That is there are no polysurfaces or lines for that matter which do not form part of a closed volume. My objective is to use yet another program with the AC3D Boolean output data to calculate volume moments of inertia. Here's the sort of thing I have in mind:

Subtract Drum (no.2) from Teeth (no.1). Union subtract output with Drum (no.2).
Union this output with Disc(no.3) to obtain Complete(no.4).

It does it fine; but it is not clean. There are invalid feathers of surfaces or edges which do not close the volume. It is the very devil to find them and it may take a full day's work to clean the drawing of these feathers.

Hopefully, in a few weeks, I'll laugh at my depression. Can anyone understand my problem and tell me "Yes, there is a way. Don't get depressed. Just keep plugging away and you'll get there. I know... I've done it!"?

Best wishes
Mike