Coating selection help 1

[cobra46]

Hi all,

I am making an electrical enclosure for an industrial shop type environment. For the outside aluminum panels we currently use e nickel and then paint the visible outside portions. The e nickel was selected because it has good corrosion resistance and electrical conductivity, both of which we need. The outside paint doesn't bond too well to the e nickel.

For the next run of parts we would like to use powder coat instead of paint to be consistent with our other products as well as painters are getting harder to find in Ca. I'm worried that the powder coat will also have a bonding issue with the e nickel. I was considering switching the e nickel to alodine as alodine is also electrically conductive as well as corrosion resistant. Alodine also makes a great base for painting. The issue is that I have been reading that alodine breaks down at high temperatures which the part will experience during the powder coating curing.

Does anyone have any suggestions to accomplish my needs?

Thanks in advance for your time.

 

[TomDOT]

1) A powder coat is still paint. It's just a paint you make liquid for application wet-out by melting it instead of dissolving it in solvent. There are a huge variety of powder coats available, from nylon to epoxy to fluoropolymers.

2) Do you have to actually plate/paint the enclosure? Aluminum can be pretty nice on its own, or anodized.

3) If you want a durable coating on aluminum, you can specify a coating system which has passed AAMA 2605 at an independent lab. Generally this will be a fluoropolymer system.

 

[cobra46]

TomDOT,

Thanks for responding.

Yes we have to powder coat the outside (visible) surface of the panels while the inside must be electrically conductive as well as corrosion resistant.

 

[TomDOT]

I'm guessing it would be difficult to plate the inside only, and powdercoat the outside only.

 

[cobra46]

I think I may have found what I need. It's a conversion coating that doesn't break down under the high temperature powder coat curing.

http://www.metalast.com/chemistry/TCP_Front.html

 

[TomDOT]

I've actually had aluminum treated with that exact conversion coating on my test rack on the Texas coast (over the water) for several years. So far, it's working as well as the standard chromate treated panels. I'm not the one officially tracking their progress, but you posting the name reminded me about them.

The deck is 6-10 feet off the water depending on the tide, and the panels are 2-3 feet higher.

 

[mcgyvr]

We have similar requirements and environments and all we do right after panel fabrication is a 5 stage chrome phosphate treatment, then mask where needed and powdercoat. No problems at all.