so i used xtc3d on my 3d prints. some spots are peeling a bit like thick paint after sanding but not alot. and there are a few spots that that are a little concave that i cannot sand so they look a bit shiny spots here and there. do i just use spot putty on those or more xtc 3d. because i have to sand it anyways so i can prime it. in fact if this was paint what do I do? or do I just use primer?