I am adding trim pieces to my plain outdoor wooden porch columns. I mistakenly used unpaintable caulk. I have seen on other forums to try using Zinsser's Coverstain primer over the caulk, however, i've already put 2 coats of latex Kilz primer on (did this before realizing the caulk was the wrong kind). Trim is glued and pneumatic nailed. What options do i have at this point?