Unfortunately once the resin has fully cured, it is not possible to soften it with heat without damaging it.  You can sand that area to remove the defect and then refill with fresh resin.  You will then need to sand the surface level to get it to match nicely and if the hole you had to dig is particularly deep you may need to overcoat the area with resin to bring the level back up to where it needs to be.   The key thing is what ever tools or sandpapers you use, it is critical to ensure the resin is properly cleaned afterwards to ensure no dust or dirt gets trapped when re-pouring.


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

It looks wet to me.  The white bits are as Oekmont said. It might with a bit of heat be close enough in ratio to fully harden off eventually.  However it has gone white due to water absorption due to getting wet.  Get it dry and somewhere warm for a few days if you can and it may drive out the moisture and fully harden off the rest of the resin


Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

To me it looks very much like you didn't mix well enough at the walls and corners of your cup. Seems like this was the very last resin you poured around the table and it didn't had perfect mixing ratio.

Hi
I used Glass Cast 3 for my mosaic table top project. I followed the instructions measured and mixed the the resin. Once I poured it I left it to set for 48 hours. The resin had set well and was clear so I took the table top outside. The following morning I noticed some white wavey lines had appeared in the resin. Picture attached.
I was wondering if there was a way to get rid of these lines.