Definitely use one of the so-called ceramic sealers. They have nothing to do with ceramic, but are polymer sealants. I used one called Rejex. First year Applied twice, then one time per year. My finish looked as good or better after five years. We were always outside as we were full time travellers, and spent most of that time in Western USA sun...... the polymer sealers go and off like wax. One thing to remember for best results; best to apply with no sunlight, then 12 hours out of sun while it cures properly. First hand experience Was with Rejex brand, ordered on-line, but imagine other polymers work as well.