On Oct 6, 12:54*pm, "Larry C"
wrote:
I have to install some 3/4 round on the outside of my house. *I am using the
PVC stuff.

I am correct to use 3 inch stainless finish nails? *If not what? *I want to
use a nail gun. *I have 100ft to do

It'd be better to use two pieces of 3/8 round. Drive the nails first
- 16d common Monel ringshanks on 3" centers - and set them proud about
3/16", then route out recesses for the nail heads in both pieces of
3/8" to house the nail heads (make sure that you reverse the grain so
you don't get warping in the PVC). Then sandwich the nail heads in
between the two pieces of 3/8 round using PVC monoclonal cellular
adhesive, and use about 2000 headless pins to hold them in place while
the glue dries. Post some pictures next Spring when you're done.

R