Filling with CA Glues

A good structural filler has the property of a similar hardness to the material it fills.  This enables flat, seamless sanding because a hard filler will cause the surrounding area to be sanded down before the filler is leveled.  A soft filler will erode before the surrounding area is feathered in.  Here's a tip:  Mix a little baby powder with the CA glue before filling gaps with it.  This makes the CA glue filler cure faster, its a little stronger, and yet it will have reduced hardness that makes it more compatible with filling gaps in modern, soft styrene plastics.