Powder Coating Question, Is primer necessary? Options

[AndrewBlyholder]

Was thinking of having some trailing arms powder coated. Got two estimates from local shops. Cheaper one claimed that they didn't need to put a primer coat on before the finish coat as it wasn't necessary, the finish coat adheres well enough by itself. More expensive shop claimed that an epoxy or polyurethane primer was absolutely necessary. Any advice from the past experience out there?

Thanks,

Andrew B.

[Rusty]

When I did my own powdercoating, I used a metal prep wash, followed by fresh water rinse. The metal prep was a minor phosphorus etcher, that also prevented flash rust.

I've never heard of a urethane primer under powdercoat. I would think that anything on the surface would cause the powder not to stick properly. That doesn't mean that there isn't a primer for that, but I've never heard of it.

Oh, and I plan to powdercoat my trailing arms, too. Smoke chrome with a clearcoat.

-Lawrence