Not sure as to the members name. He cleaned the roof of his RV and used a product called Duck Seal, sold at Menards which is like Lowes and Home Depot here. It is a kinda Northern store. I tried to search it here and couldn't find it but its been a couple of years since he had done it, I think he only did two light coats and was gonna apply a third but didn't. Think he said it sealed and covered it well. this will give you another option to look at. i think this
LINK will show what it is. Gonna do mine probabely this year.