With the small details on this you'd be better off alternating sanding and heavy coats of filler primer. The Smooth-on epoxy coating tends to fill in interior corners and round exterior corners - it's not great for things with fine sharp edged detail. Filler primer does as well to a lesser extent but it goes on a lot thinner and it's easier to control.
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You did a good job with that, Lukyanov. What steps did you follow to achieve that finish?
Thanks.
Quality of lightsaber largely depends on the printer model and plastic I think.
This is my first experience in processing 3D-printed model.
In the beginning I had bad-quality detail with dropped out plastic threads (somewhere). Printer layer thickness is 0.2 mm.
First I use sandpaper #320, than #600. After roughing I treated with acetone on rag (with finger force pushing) to a smooth condition. Than finishing with sanpaper up to #2000.
Somewhere defects are seen, but I am satisfied (I hope looks like celebration prop).
After processing with wool, ABS-plastic gets shine like a metal (later I take a photo).
Waiting modified emitter from guabe (first printed part has super-****ty-quality, you can see it earlier).
Everyone understand me?

I'm from Russia, my english can be bad.
Here's another weaver-ABS-detail finishing by me using only sandpaper:
In the begining:
PLA-plastic much harder to handle with with abrasives, and it not treated with acetone. Here is my cap (I'll cover it later with matte varnish)
I have a question: what kind of paint should I use to color smooth parts? Acrylic does not hold on it...