Smooth edges when casting

Does anyone have any advice or tips on creating a smooth edge when casting resin? I’m new to resin and have not started my project yet but have seen so many pieces that dry with a lip. I know that can be sanded down but I’m also wondering if there’s a way to make it smoother when casting so there won’t be as much sanding to do after.

I haven’t done resin casting so cant help with ideas to prevent the surface tension from creating a burr, and I hate sanding. You might try filing the edge before sanding, it will remove material faster than sanding. But I don’t think Ive seen a sharp file yet at the makerspace. If you cast something I could bring in a few to try to help decide what to buy. Nice thing about a file is you can take high spots out easier than sanding which tends to follow contours

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It all has to do with the mold. If the mold has sharp corners then the resin will. I have a couple of silicone molds that don’t give me any sharp ones but my pen molds have very sharp ones


To camp on to Randy’s idea… if you have a spokeshave you can radius resin with it. You’ll want it to be freshly sharpened and set for a light cut. I just tried mine on a piece of scrap and it leaves a pretty clean surface