Do parabolic mirrors need polishing to reflect infrared effectively?

[cj]

Summary:: Do my parabolic mirrors need to be really shiny to reflect infrared?

I have 2 really old CENCO parabolic reflectors.

I need to use them to demonstrate infrared light radiation by placing a heat source near one mirror, reflecting its heat to a second parabolic mirror and concentrating that mirror's reflected light to a match placed at the focal point.

Neither mirror is very shiny anymore. Should I clean and polish them to get them really shiny, or does this not really affect the reflection of IR?

Thank you!

 

[Baluncore]

Neither mirror is very shiny anymore.

You must remove the surface contamination of oxide and dust that will block IR.
Start with soapy water. That might fix a dust or dirt problem.
Polish the surfaces to clean them, but make sure that you do not leave an IR absorbing film from a commercial polish on the final surface. Finish with a mechanical polishing.

You have an opportunity to experiment with before and after assessments.

 

[cj]

Good advice, thanks!

 

[sophiecentaur]

You have an opportunity to experiment with before and after assessments.

Always. If ever in doubt then experiment.

Very powerful for argufying on PF, too. Such evidence works at least as well as CERN's for appropriate situations. It shows people you are really involved in the stuff.