The authoritative public forum
  for Metal Finishing since 1989
-----

Surface Reflective at 365nm?

I am currently looking for a coating, polish or finish which has a high reflectance at 365 nm. We are trying to make a reflector assembly. We are currently using 6061 as our Al base. We have tried several methods but need a true solution. Any information that you could offer would be helpful. Thank you.

Chris Langel
Minneapolis, Minnesota
2000

---

Hi Chris,

As far as a brighter finish goes, switch away from 6061 for the first step. Generally speaking bright reflector type work is done with strictly 3003 material, and has survived to fill this market segment very well. From there, you can have the material bright dipped or electropolished and then anodized with a very thin coating of 5-7 microns and it will shine nicely and last for a considerable amount of time. If your part(s) will not be used in outdoor environments you might be able to leave them in the un-anodized state to get the brightest finish possible. The electropolishing imparts a very thin oxide coating on top of the aluminum that will protect it somewhat. Its not near as durable as an anodize, but it also does not dull the surface like an anodize would, even if it is minimal.

Matthew Stiltner
plating company - Toledo, Ohio
2000

Thank you for the information but unfortunately we are require to use Al billet and not sheet stock. Also the reflector will be immersed in water.

Chris Langel
- Minneapolis, Minnesota
2000