Applying Vinyl to HDU signs

[CNCARTWORKS]

I'm sure that this question has been asked before but my search did not come up with anything.
I want to apply vinyl to my hdu blank. I'm trying to figure out how to adhere it to the material.
I know that I can cut through it with a straight blade cutter because that's how I do my masking with avery mask, but that's not permanent. Anyone have a proven technique?

[dvmike]

I've done this once to add a full color vinyl decal to a routed sign.
I sanded the area with 400 grit and then sprayed with FCS88 primer for precision board. The primer has heavy solids and provides a very smooth surface. Then lightly sand again with 400 before shooting the surface with an auto grade enamel. This will give the vinyl a smooth,slick surface to adhere to. After the vinyl was put down I finished up with a Dupont clear.
There may be an easier way, but I didn'`t know of one.
The sign looked great and has been around for about a year now, and still looks great .