What metal is used in A-Designs and Chandler chassis?

[john12ax7]

I like the look of these better than powder coating. Are the chassis zinc plated steel or something else?

 

[john12ax7]

Another pic

 

[Echo North]

Usually copper plating.  It actually functions better as well since the grounding has better continuity throughout the chassis.

Mike

 

[john12ax7]

Usually copper plating.  It actually functions better as well since the grounding has better continuity throughout the chassis.

Mike

The grounding is part of the appeal for me as well.

 

[shabtek]

looks like brushed al aluminum. probably anodized gold color not copper on aluminum

 

[Echo North]

Looks the same as the purple audio sweet ten rack:
http://www.purpleaudio.com/sweet-ten/

"The Sweet Ten top, side, and back panels are finished in trivalent yellow chromate cold rolled steel instead of painted steel for improved grounding and shielding."

I have an a-designs.  It's steel for sure.

 

[Timothytitus88]

It's yellow (or gold) zinc electroplating.

after 2secs of google....... (lots of info out there)
http://www.zink-nickel-kft.com/zinc-plating.html

These enclosures are not made from a pre-finished sheet of this material, rather the parts are fabricated from raw (black) mild steel (laser cut or punch and then folded) and then the finished piece is electroplated.

The nice texture is from putting a surface finish on the raw (black) mild steel before electroplating. in the first pic it looks like a fine random orbital sand, giving the matt finish, and in the second it is a brushed finish just like Ali or stainless.

Particularly in a production environment, steel is cheaper, easier to work and stronger for this kind of application, where aesthetics are of second importance. The electroplating is for corrosion protection. The fact that you can clean up the steel after fabrication and then add a yellow color to the electroplate to make it look acceptable (even nice) is a bonus.

The problem with electroplating is that it is not necessarily uniform across the work piece, and certainly not consistent between batches. therefore no good for front panels where aesthetics are of prime importance.

Cheers,

Tim

 

[Echo North]

The brushed finish in the 500HR pic is a time saver finish (probably class A).  It's basically a big sanding machine they feed cut/punched parts into for a brushed look.

The Hairball enclosures are done this way.

 

[12volts]

Very simple. It's Zinc Chromate. Very good on mild steel and it's cheap. I've spec'd it on loads of sheet metal work job over the years.


Frank B

 

[gyraf]

IIRC there is a ROHS-related problem to this type of surfaces (trivalent chrome or something)...

Jakob E.

 

[JohnRoberts]

Very simple. It's Zinc Chromate. Very good on mild steel and it's cheap. I've spec'd it on loads of sheet metal work job over the years.


Frank B

+1  that's what I recall it being called...

It has it's pros and cons. 

Pretty old school if you are going for that look.

JR

 

[MicDaddy]

RoHS doesn't like cadmium, which does tend to look a sick yellow or gold color.  Trivalent processes, as far as I knew, are RoHS compliant.  Even so I believe there is a RoHS exemption where when cadmium is used in an electrical connection.

 

[gyraf]

ROHS also includes hexavalent chromium materials etc...

 

[EisenAudio]

From what I understand, traditional hexavalent chromate (i.e. gold iridite or yellow dichromate) is non-compliant in part because it's quite hazardous to the workers who apply it and the environment. Unfortunately, it's difficult to imitate this iridescent finish (which we've seen in pro audio gear since the beginning) using trivalent chromate alternatives, which are safer and often RoHS compliant. Purple had to search hard for and invest heavily in the Sweet Ten's specialty finish. Not wishing to follow suit, I simply specify "zinc plated clear trivalent chromate" for my Cold Rolled Steel parts. As far as some casual research and my metal fabricators have assured me, this is RoHS compliant. It's also no more expensive, readily available, and looks/feels just like any traditional zinc-plated steel. Perhaps the only downside with all trivalent chromates I've encountered is greater susceptibility to the appearance of fingerprint residues. Regardless of aesthetic preferences, I usually recommend electro-plated steel enclosures, rather than painted steel, stainless, or finished aluminum, as I find this affords the best of both low and high frequency shielding.

 

[abbey road d enfer]

Electro plated steel comes in pre plated protected sheets.
Your metalworker will punch, bend, drill, tap, and so on and take the adhesive protection at the last moment, so you don't have to take care of finding an electroplating company.
It leaves the edges unprotected and susceptible to rust though.
That's how 90% of chassis are made today.

 

[EisenAudio]

Electro plated steel comes in pre plated protected sheets.
Your metalworker will punch, bend, drill, tap, and so on and take the adhesive protection at the last moment, so you don't have to take care of finding an electroplating company.
It leaves the edges unprotected and susceptible to rust though.
That's how 90% of chassis are made today.

You are describing a cheaper process, such as galvanized or galvaneal. Indeed, the edges do rust over time, which is why I stopped using this a few years ago. My metal fabricator laser cuts the cold rolled steel, then zinc plates it, and then applies a clear coating. They do so because I specify it as such and pay extra (which still isn't very much). The gold iridite and yellow dichromate conversion processes that the original poster is asking about are done in a similar manner, with the parts being dipped AFTER fabrication.