Adapter (for Halloween PVC Fence)

In my faux wrought iron Halloween fence (which is based on [this](http://www.instructables.com/id/Halloween-Cemetery-Fence/?ALLSTEPS) and other versions of the same idea), each 8 foot section has some sort of post on either end.

Posts that are simply in between two parallel sections are made of 1.25" PVC. (Posts at the corners of the yard are larger). I plan to mount one of my finials to each of these 1.25" posts, but at the size I want the finials are meant to fit 0.75" PVC. Since these a