Just repainted my old home (1923) – lap siding – used Behr paint w/primer included — scraped off all old paint. Now bubbles and blisters have formed. What caused that and how can I prevent it from happening more and more?

I want to paint my kitchen gas stove inserts. These include the burner grates on which you place the pan as well as the round flame regulators and the tray/drip inserts. I know that people have painted refrigerators etc, but am not sure that there is a paint or type