On Tuesday, May 15, 2018 at 8:07:41 PM UTC-5, DerbyDad03 wrote:

Am I expecting too much from this rig?

I would try increasing the air pressure to the max your gun is recommended for.

On this video - https://www.youtube.com/watch?v=k6L_ArXCbYs - I wasn't too impressed with the speed of the paint removal (one coat of already maybe loosen paint?). I would think any surface, with a primer, would be even slower to blast. I might suspect the primer coat on your vents have been baked on, at the factory, making that coating harder to remove, using the walnut grit, if you're wanting to remove the primer, also.

Test with a bit of fine sand. With that delicate of small gun set-up and pressure regulation, controlling the more aggressive sand might be easy enough, hence not damage your vents' metal.

Sonny