Effects of Steel/Aluminum mast behind GH

[iblackford]

My build plans for an upcoming GH build include bolting a piece of plexiglass to a metal pole that would serve as my mast. The plexiglass would hold all the reflectors, narods, and mounts for the feed element.

The mast would be <1/2" behind the reflector plane, but perpendicular to the reflector elements. Would this adversely affect the antenna? I know most folks here use PVC, but I think steel or aluminum would work well also, and I'd like to try it.