Insulating perforated metal sheet

Hi,

you have to make the edges round (also any other sharp edge around the plate) because these will produce a much higher electrical field strength and thus breakdown if not rounded.

Prolonged deburring with an abrasive coated brush may be good for this purpose.

Then anodising as proposed but chromium 6 is no longer allowed except for some special applications in aircraft parts.

Try to get a thick and porous anodising, porosity then filled with epoxi.

Material selection is important for good anodising!

Any anodising that is giving good adherence and not too hard coating may be good.

Too hard a coating will easily crack at too sharp edges.

Conformal layers are often done with Parylene but this is expensive. So epoxi may be good too.

With proper selection and proper condition this will cure within seconds to minutes depending on type and temperature.

At CIBA times producing Araldite there was a high temperature curing epoxi (AT1, dry powder, melting at above 90°C, cured at 150 to 300°C) that could be flame sprayed to give insulating layers.

If this is a part where safety of persons may be impaired I would never put this high a voltage on it but change to a totally insulating plastic or ceramic material.

RHABE