Have been painting some eyes and am having a small problem. I am using Sally Henson's Hard as Nails to seal the eye but if I do any brushing more than touching the eye the paint wants to start smearing. I am using some type of Plasti-kote paint I bought at Wal-Mart for paint. I am not sitting there brushing but do make a stroke or two to get a even coat. Can someone give suggestions as to fix? Thanks