Finishes for sheet metal assemblies that do not have welds 1

[WilsonT]

Hello,

Would you please let me know the preferred finish for electronic sheet metal assemblies that do not have welds?

I've been asked to specify black powder coat for such assemblies. But I think this causes more problems that what it's worth. I would rather specify either a clear or black zinc plated finish.

Please let me know your thoughts. Thank you.

 

[MintJulep]

I like blue.

 

[KENAT]

What material, what functional requirements(conductive, clean room...?), what aesthetic requirements, what regulatory compliance requirements, are there any inserts or similar...?

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[drawoh]

WilsonT,

For containers of working electronics, I strongly prefer chemical film. You can specify it RoHS compliant. It is conductive, making it part of a Faraday cage that reduces your EMI/RFI. Look up MIL-DTL-5541 if you want to get official about it.

The only problem I have with sheet metal housings is the presence of welding. Since the weld filler is not the same material as the sheet metal, an anodize finish will show off your welding.

Failing all that, I would go for polka-dots.

--
JHG

 

[mcgyvr]

We use black powder coat for all our enclosures (mostly aluminum) with a chrome phosphate pre-treatment.. Masked in certain areas for grounding if needed.

 

[berkshire]

There are a couple of items missing here. What material is the sheet metal enclosure made of ? Steel, Aluminum, Brass?
Whoops , I see Kenat already asked that question.

 

[GearsNsparks]

On our Aluminum 5052-H32 enclosures for our electronics equipment, we typically chem film all over per MIL-DTL-5541 and then powder coat customer facing surfaces as necessary.