It's a 60+ year old house with cedar shingle siding that has been painted several time. We can see where the old paint on the shingle on the covered poarch have blistered up and pealed in the past. The new paint, on less than a week has started blistering up there too. It's the only place on the entire house that's doing it. What gives and how can I fix it short of using a wrecking ball?