not sure, ive just finished buildin my own viv to house my veilled, i stained mine using yacht varnish which is safe cheap & really waterproof. just make sure you put a few coats on & put some airvents in for circulation, hope this helps
One thing i do wen i stain and varithane my cages is i always let them dry/air out at least 3 to 4 days outside to reduce illness due to fumes the stains and varithane produce.