What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Alodine and prime sequence

mulde35d

Well Known Member
Friend
I am alodining the entire aircraft during the build. After alodine I assemble the aircraft and continue building. As I approach painting the interior my question is, what prep do I have to do to the alodined metal prior to applying the primer / paint. Do I need to re-scuff with a scotchbrite and clean or simply clean with a degreaser and spray the primer. Probably a simple question but I have so far only gone up to applying the conversion coating and have yet to prime for paint. Thanks
 
Alodine

You don't want to scuff Alodine. It's pretty thin and will get scuffed off.
Ideally you scuffed prior to Alodine. If not, try some tests to see how the paint sticks. Even an acid etched surface should hold paint pretty well.
 
Alodine, prime, then assemble

While I won't claim to be an expert in this area, I have alodined, primed, then assembled so far during my build. The only exception are the really long or really big & flat pieces where I just cleaned/scotchbrited/primed before assembly. In essence I used the alumiprep / alodine stage as my prep for priming to give a clean & good surface to bond to.

My logic was that I wanted each individual part to be "complete" before assembly.
 
I recommend you call the primer manufacturer and discuss the process of priming after alodine. Southern Polyurethane makes great two part epoxy primer and they want the primer sprayed in less than 24-48 hours after prep and alodine. Naturalizing the acid in the alodine (rinse process) is important before epoxy primer. As the weather changes temperature is also important when applying paint. Excellent prep and the timing of each coating is specific to the manufacturer.
 
You don't want to scuff Alodine. It's pretty thin and will get scuffed off.
Ideally you scuffed prior to Alodine. If not, try some tests to see how the paint sticks. Even an acid etched surface should hold paint pretty well.

Agreed. Once you have scuffed during the etch process and then done an Alodine treatment you should not have to do anything more than ensure the surface is dirt and oil free prior to applying primer for paint.
 
I would clean using Prepsol or similar. Absolutely do not scuff the Alodine surface. Doing so will negate all the time and money you spent on the Alodine. FYI, Alodine improves the bonding of the primer to the aluminum.

Charlie
 
Last edited:
Back
Top