Aluminum chassis - finish required

[pula58]

.090 5052 H32 aluminum

Any special finish required for an amplifier chassis ?

[tubeswell]

anodising and laser engraving would be special

[pula58]

thanks tubeswell..I should have been more clear in my post. I am wondering about the electrical properties of the aluminum and/or corrosion.
Do I need a finish on the aluminum for this?

[tubeswell]

I never bother with aluminium corrosion. Unless you're going to be dipping it in salt water...

[Teleguy61]

Unless you're going to be dipping it in salt water...

Or leaning over it at a sweaty gig............

[steve_p]

Aluminum will form a clear layer of non-conductive aluminum oxide over time.

A chromate conversion finish (also known as irridite or alodine), will create a conductive finish on the surface.

Depending on the type of chromate conversion and alloy being coated, the surface may look like bare aluminum (silver-ish), up to a very deep gold color.

Steve

[alvarezh]

In aviation, they control corrosion with a coat of Alodine and then a coat of Zinc Chromate.

If you are going to play close to the beach, it's a good thing to do. Ocean spray even if you don't feel it, is in the surroundings.

If you can, take a trip to your nearest aviation paint shop, you could probably find someone to give some tips on how to apply it.

All the best.

[The New Steve H]

This sounds like a question I would ask. If it's not worth worrying about, don't worry about it.

[Super_Reverb]

thanks tubeswell..I should have been more clear in my post. I am wondering about the electrical properties of the aluminum and/or corrosion.
Do I need a finish on the aluminum for this?

So the aluminum itself doesn't become less conductive, but a thin layer of Al oxide grows on the Al chassis makes the chassis surface less conductive or non-conductive.

So if there is intimate contact between a chassis bolt and chassis or jack and chassis, does Al oxide slowly form and render the chassis ground connections more resistive? Is the TAG R/D department working this?

rob

[ToneMerc]

So if there is intimate contact between a chassis bolt and chassis or jack and chassis, does Al oxide slowly form and render the chassis ground connections more resistive? Is the TAG R/D department working this?

rob

No use reinventing the wheel, thats what electrical grade NO-OX is for. All the ground connections in my builds get it.

TM

[alvarezh]

Good tip TM never new this existed. I went ahead and read some reviews, apparently it works as claimed and does it very well.

Thanks.

All the best.

[Prairie Dawg]

Aircraft Spruce will fix you up.

http://www.aircraftspruce.com/catalog/c ... ne1201.php

[chief mushroom cloud]

Aircraft Spruce will fix you up.

http://www.aircraftspruce.com/catalog/c ... ne1201.php

hah! one of my fav places to shop

[pula58]

So if there is intimate contact between a chassis bolt and chassis or jack and chassis, does Al oxide slowly form and render the chassis ground connections more resistive? Is the TAG R/D department working this?

rob

No use reinventing the wheel, thats what electrical grade NO-OX is for. All the ground connections in my builds get it.

TM

This is great information, thanks! No-ox !

[gingertube]

Alodine treatment can be purchased in a "felt tip pen" for doing small areas and patch ups.
Do under and around the earth connections, leave the rest to acquire its natural oxidized finish.

The Alodine Pen has the following written on it.
"Alodine 1132 Touch-N-Prep Coatings" made by Henkel in Michigan, USA.

Alternatively bare Hammond Chassis can be purchased with alodine finish.

I build stuff for airborne use in the day job, Alodine is our preferred finish for this stuff. Our critical laser receiver was anodized instead and I had HUGE heaps of trouble getting a decent shield to keep the approx. 125MHz Air Traffic Control Radio out of it. Only found that after fitting the prototype to the aircraft of-course, worked perfectly on the test bench. Eventually rebuilt it with alodined enclosure.

If anodizing you need to remove the anodizing around any chassis earth connection because it is a non-conductive finish. That is not easy due to the hardness of anodized finish.

Cheers,
Ian