Question about zinc chromate primer

[LegacyT]

I'm in the process of repainting my outdrive. I'm scuffing the whole outdrive keeping the original Factory Volvo Penta paint where able and sanding to bare aluminum in spots to get rid of corrosion. I'm alumaprepping the aluminum areas then sealing it with rattle can zinc chromate to prevent corrosion before I can top coat everything. I plan to then use polymide epoxy primer and top it with Supermarine Ironside urethane. My question is: before I spray the epoxy primer do the zinc chromate covered areas need to be scuffed again? Or will the epoxy primer bite into the zinc chromate on its own?

 

[DeepBlue2010]

Re: Question about zinc chromate primer

Zinc chromate primer is not what you need if you are going to use epoxy primer. Use Alodine instead to get your conversion done.

 

[zool]

Re: Question about zinc chromate primer

Alumiprep is just a phosphoric acid wash..after that you can either use a ZC primer, Alodine, Epoxy primer, or a wash primer...no need to double dip, in fact, its not recommended.

I would just seal everything with the epoxy primer, and paint it.

 

[LegacyT]

Re: Question about zinc chromate primer

I'm prepping the outdrive myself on weeknights and using ZC primer to seal the aluminum before I can fully paint all parts at once at a paint shop. The outdrive is all dissassembled and I know aluminum has to be etched and sealed or it will oxidize in less than half an hour and cause problems for adhesion. Thats why im using ZC. Just want to know if the epoxy will grip the ZC as is or if I have to rescuff the ZC'ed areas.

 

[zool]

Re: Question about zinc chromate primer

The point is, epoxy will stick to bare aluminum as good if not better than ZC, but its ur drive, so have at it....you only use a light dusting of ZC...you don't have to scuff it, but you can if u want...

Aluminum only has to be etched for regular or build primers...But you should still use the alumiprep to clean it, make sure you rinse the alumiprep a few times with water, to remove the residual acid.