I didn't have my thinking cap on when I posted the above response.
Fill the open areas with the epoxy and use wood flour or silica..... Then on the inside run a wood flour and epoxy fillet with the thickest portion over the seam where the light is coming threw..... That will stop it dead in it's tracks.
Fill the open areas with the epoxy and use wood flour or silica..... Then on the inside run a wood flour and epoxy fillet with the thickest portion over the seam where the light is coming threw..... That will stop it dead in it's tracks.