Zinc Chromate Primer on fiberglass cowling

[Seadoomanls]

Hey guys... I am going to be painting my 1994 Yamaha 115 outboard this week... I have read a lot on the topic so I feel pretty confident and will post pictures soon. I ordered Marpro outboard paint because I get it at 65% off of retail (stepdad owns a prop shop)... I order 3 cans of the zinc primer, 3 cans of my OEM color and 3 cans of clear. My question is, since I bought all that zc primer, can I use the zc primer on the fiberglass cowling. I understand it isn't needed, and that the zc primer is needed on bare aluminum, but CAN I use the zc primer so it doesn't go to waste?? Will it hurt anything is my question? I plan on sanding the cowling and using an auto type fiberglass bondo filler for a few scrapes and gouges that are too deep for primer to take care of... Then I was hoping I could use the excess zc primer right on the fiberglass cowling..

Thanks!!

 

[GT1000000]

Re: Zinc Chromate Primer on fiberglass cowling

You can, but it is a waste of a product not really intended for the purpose...
Since Dad owns the shop, can't you return it?
Do your repairs then lightly dust on the ZC primer...then apply a couple of heavy coats a good filling/sandable primer on top, let it dry thoroughly, this will allow you to get that almost perfect surface for top coating by wet sanding with 320-600 grit...
Please, post some pics of the process...we'd like to see it
Good luck and have fun!

 

[Bob_VT]

Re: Zinc Chromate Primer on fiberglass cowling

I would not bother to use ZC on the fiberglass. Use a regular primer as stated above. ZC creates a chemical bond for aluminum and metals........ save the ZC for future aluminum touch ups.

 

[Mud Puppy]

Re: Zinc Chromate Primer on fiberglass cowling

In aviation, Zinc primers are used as a anti corrosion barrier for malleable steel (also called cold galvanizing when used on tin), where the chromium serves as an anti corrosion preventative for aluminum. Not really sure why you would use Zinc on AL, but a waste of money for sure on composites and serves no real purpose or added protection.

Use a good etching primer and/or primer sealer. To build up minor voids use a high solids build up primer if need be...

have a smooth surface from prepping and the last one one can go away. Sand or scuff lightly and shoot topcoat. I would use urethane if your not using gel but that is just me..

my 2cents worth, but that's aviation, and even though they are very similar, I have been so very wrong before, when it comes to what happens with boats, so I'll just go set in the corner and shut up.

 

[Seadoomanls]

No Title

We'll I finally had time to post the pictures. All in all I am happy with the paint job...

 

[jbcurt00]

We'll I finally had time to post the pictures. All in all I am happy with the paint job...

and the forum hickups are keeping the pix from showing up........

Glad you're happy w/ the results. Now, about those pix :facepalm:

 

[Seadoomanls]

Hopefully this works for pictures....