We are spraying a second coat of matte poly 24 hours after first coat (with light 320 sanding in between) and sometimes we get what the picture shows, In this case every single board (a lot!) that was sprayed did this. The poly is slightly thinned with turps. (I thought this was a bad idea but the spray guy showed me the can and it says mineral turps is okay for thinning.) Same can of poly as was used for the first coat (which looked perfect) yesterday. What did we do wrong?