thoughts/suggestions for sunburst backer board

[tomsteve]

i have myself a present/project to get kicking on.trying to find a picture of a finished one showing how im planning it is difficult but heres a pic to get an idea. im planning on keeping the rays flat instead of overlapping and alternating thicknesses of each ray, then mounting them on a backer. 48" wide and 24" tall which im thinking of PT plywood. backer will be cut to the radius of the sunburst.
this isnt a part of a siding job- just an outdoor decoration thats going on the north side of a barn.
however, with the quality of regular ply being oh so wonderful, im wondering if PT ply for the backer is a good idea or not. all of the construction ive done in my life i dont recall ever using pt ply so dont know how it might react,twist,warp,etc.

what say all ya'll. what would you suggest to mount the rays onto?

[jteneyck]

I wouldn't use PT plywood.  I'd think about Extira.  Glue the pieces on and then prime and seal everything really well.  Never used it yet, but TOH and others seem to think it works well.  

John

[Cooler]

For this one, it looks like he tapered pallet boards, stained them, and then glued them to a piece of plywood.  After it was all glued up a circular saw could trim the outer edges to size and then "picture-frame" with molding.

Note:  These are probably not pallet boards as this is a commercially produced item.  But pallet boards would seem to work.

[tomsteve]

I wouldn't use PT plywood.  I'd think about Extira.  Glue the pieces on and then prime and seal everything really well.  Never used it yet, but TOH and others seem to think it works well.  

John

thanks for that. i can get it local so can go take a look.