CAD Plated Parts, How to Prime and Paint?

Steve Pierce

BENEFACTOR

Graham, TX

• Dec 8, 2012

• #1

I notice that Dakota Cub sends out the steel parts Cad plated and I got some control cables from Univair where some of the fittings on one cable were primed and some were plated. The plating doesn't seem to hold primer very well. Any tricks other than media blasting for primer adhesion?

 

C-90 Cub

Registered User

Alexandria, KY

• Dec 8, 2012

• #2

Had the same problem with painting chrome in the auto industry. Might try Zinc Chromate primer first. It is the only thing I have found that sticks to Chrome.

Steve

 

Speedo

FOUNDER

TN

• Dec 8, 2012

• #3

Steve, your question made me curious, so I did some Googling. Because of the difficulties you described, I was surprised to find this:

"Cadmium plating provides excellent paint adhesion properties, and it is more resistant to stripping than zinc plating. These properties influence the preference for cadmium plating over zinc, particularly in the aerospace industry."​

This claim is made by Automated Finish Technology Corporation. Here is their contact info, and (with a nod to Steve Eaton) it looks like they might speak your language:

2605 Skyway Dr.
Grand Prairie, TX 75052
972-988-1999
972-641-7365 fax
sales@aft-corp.com


​

I also found this paper, which suggests that paint curing fumes, in sufficient concentration and under conditions of heat and humidity, causes oxidation of the plating. It also indicates that changes in the paint curing conditions fixes the problem. http://www.dtic.mil/dtic/tr/fulltext/u2/622280.pdf

​

 

Last edited: Dec 8, 2012

Steve Pierce

BENEFACTOR

Graham, TX

• Dec 8, 2012

• #4

Interesting. Has not been my experience at all. The paint tends to scrape off very easily especially on sharp edges. Thanks Eric, I will give them a call and see what I might be doing wrong.

 

S

sierra bravo

Registered User

• Dec 8, 2012

• #5

Last time I tried Variprime stuck just fine. Other than cleaning there was no prep necessary.

 

Gordon Misch

MEMBER

Toledo, Wa (KTDO)

• Dec 8, 2012

• #6

I ran into the same thing - the plating on the parts from Dakota is real slick.
Maybe acid etch? I'd bet Alumiprep would work?

 

DesperadoPilot

FRIEND

Brazoria, Texas

• Dec 8, 2012

• #7

I ran into the same problem. I repainted using a "sealer" first, then primed and painted it and had no more problems.

 

Bearhawk Builder

FRIEND

In the woods

• Mar 13, 2018

• #8

A few years later - Is this still the consensus on the cad plated steel parts? Have you found epoxy primer to adhere well to the cad, scuff and shoot?

 

RaisedByWolves

FRIEND

Tx

• Mar 13, 2018

• #9

Bearhawk Builder said:

A few years later - Is this still the consensus on the cad plated steel parts? Have you found epoxy primer to adhere well to the cad, scuff and shoot?

Click to expand...

I had them prime the aileron hinges before they built it. the rest of the flap hinge and aileron hinges i blasted primed and painted

 

Bearhawk Builder

FRIEND

In the woods

• Mar 13, 2018

• #10

So you blasted the cad plating off? Does the plating not hold up? If not they should know.

 

RaisedByWolves

FRIEND

Tx

• Mar 13, 2018

• #11

Bearhawk Builder said:

So you blasted the cad plating off? Does the plating not hold up? If not they should know.

Click to expand...

Seems like the primer and paint doesn’t like to stick to it. Yes I blasted the new flap and aileron hinges and primed and painted them prior to install.

You should see if airframes will sell you the doublers for the performance stol flaps so if you wanted to add them down the road it would be easier


Sent from my iPhone using Tapatalk

 

cruiser

Registered User

South Glens Falls, NY

• Mar 13, 2018

• #12

A vinegar bath overnight will remove the cad plating. Maybe a short bath to just “soften it up”?