For The Aluminum Hull Guys

[Mojo^]

Is there such a thing as a self-etching paint that would allow me to paint the interior of my Jon without having to prime first? I already have it down to bare metal inside and out in preparation to steelflex the outside. If I have to go the prime and paint route, I have to apply paint (Rustoleum?) within 24 hours of primer application or sand it to reactivate the finish, right?

 

[Woodonglass]

Re: For The Aluminum Hull Guys

I'm not sure of your question?? Are you saying that your self etching primer is saying that the top coat has to be applied withing 24 hours of it's application? What brand of SE primer are you using?

 

[sschefer]

Re: For The Aluminum Hull Guys

There are a couple of products I'd like to see you use. The first is Aluma-Prep 33, and the second is Alodine 1201. Most automotive paint stores carry both products or can order them for you. Both products go on with a spray bottle and a brush and are rinsed with water. The result will be and etched and then chromatic converted surface. Essentially you'll get the same results as that of applying that nasty Zinc Chromate or a 2 part epoxy primer. This is the way I prep all my Al now and the results have been far better than I ever expected.

 

[Mojo^]

Re: For The Aluminum Hull Guys

In a previous life I was a Quality Manager at an aircraft manufacturing facility that had a large paint line. Using zinc chromate as a primer on aluminum parts that had been treated with alodine 1200, I recall that parts had to be painted within 48 hours (not 24) of being primed or the surface had to be reactivated by sanding and wiping with MEK. This was to ensure proper adhesion of the paint. I just wasn't sure if the same holds true for stuff like Rustoleum. Can I prime now and wait a week or more before painting without sanding the primer?

I have Aluma-Prep 33 on order but hadn't considered using alodine.

 

[sschefer]

Re: For The Aluminum Hull Guys

You can paint directly over the Alodine without priming. The time thing is just a guesstimate. The true test is if when you touch it, it leaves a finger print but the paint doesn't come off on your finger. That's when you know it's ready to recieve the first top coat. If you touch it and it doesn't leave a finger print they you should wait until it's hard enough to sand or wipe it down with MEK to break the skin. The purpose of primer is to fill any minor surface imperfections and it's those surface imperfections (sanding scratches) etc that cause the primer to grip the substrate. The top coat needs to be able to merge with the primer coat in order to take advantage of it's grip on the substrate.

If you alodine the substrate, the top coat will grip it just like the primer would have so you accomplish the same thing. As a side note, Merc high performance off-shore motors don't get paint, just alodine 1201. That's what the gold colored blocks are all about. That's when the lightbulb came on for me!

 

[ezmobee]

Re: For The Aluminum Hull Guys

I used this stuff on my transom: http://www.duplicolor.com/products/selfEtchingPrimer/ got it at Pep Boys. The paint there (unlike other areas on my boat) seems to be holding up well.