Friend kindly offered to install vinyl railing kit on patio steps (I have balance issue). It looks great and is solid BUT in cutting the top rail, the cut was not straight. Where the top railing meets the connector on the post there is a noticeable gap: 2" long and 3/16 wide. The rail is hollow, so it looks like a hole. I am not handy lady and am not sure if I can caulk this, what type caulk, best approach? I would very much appreciate suggestions. I think first pic. might make it appear somewhat larger than it is, but gives closeup.