Zinc Chromate vs Zinc Phosphate

[shaw520]

I already have a good oil based enamel w/hardener for top coat,.. Im looking for an aluminum compatible, durable primer/base coat. Suggestion Welcome

 

[Watermann]

I use self etching primer and have used it on 3 boats for a total of 52 feet of aluminum boats. No complaints or issues with it at all.

 

[shaw520]

Thats alot of aluminum WM,..and the self etching primers seem to be the simplest and cheapest route

 

[gm280]

I have always used Zinc Chromate. Why? Because that is what the we used when I worked repairing aircraft for the Air Force. They determined what works best for their aluminum painting and so I figured I'd use it as well. Does that mean self etching primers won't work. No! I am certain they do a capable job as well. I just used Zinc Chromate from past experiences and it has worked very well for my projects. JMHO

 

[shaw520]

Searching you can find good and bad experiences with both,.. With aluminum prep is everything,.. It's begins to corrode immediately so a neutralized/converter is a must,..Alumiprep 33 the stuff is big $$. Also your not supposed to use steel/wire brush,.. Sand paper only.

 

[harleyman1975]

I use epoxy primers myself but that is expensive for the average DIY'r Either of the others will perform just fine as long as boat is not in water for extended periods of time.

 

[lckstckn2smknbrls]

A light coat of self etching primer followed by primer of the same brand as the top coat.

 

[shaw520]

No Title

Been looking at the epoxy primers $$$,...but,... its not like I WONT use it ! I have (4) to do asap.

 

[harleyman1975]

You know that they make self etching epoxy primer too!

 

[gm280]

This priming question seem to crop up every few weeks it seems. And the only right answer is, whatever you want to use is the right primer. Similar to, which is the best 2 cycle oil, or what type paint is the best, or even should I use synthetic or regular oil, or even should I use high octane fuel or not, most anything else in that which is the best realm, everybody has their own opinions and likes. So use which ever quality primer you like for aluminum. And it will be fine.

I go with Zinc Chromate because, the government did their testing on their aircraft for the best longest lasting type primer and they chose Zinc Chromate, I figured I'd go with their testing efforts and use the same. But epoxy primer it good and so is self etching primer. So make your choice and it will work without issues. JMHO

 

[shaw520]

Thank you 280,.. We all know that the properties of aluminum can make it difficult to get paint to stick. I attempted to paint my aluminum rims on my GMC last year because I got tired of scrubbing the oxidation off every few weeks,.. I tried all kinds of prep, self etching primers, good quality paint, .... less then a year later the stuff is peeling off.

 

[gm280]

Thank you 280,.. We all know that the properties of aluminum can make it difficult to get paint to stick. I attempted to paint my aluminum rims on my GMC last year because I got tired of scrubbing the oxidation off every few weeks,.. I tried all kinds of prep, self etching primers, good quality paint, .... less then a year later the stuff is peeling off.

shaw520, the same holds true for any quality paint job, and that is preparation, preparation, preparation. You have to have the aluminum metal surface absolutely clean. And then you have to use a quality primer that makes the transition from the cleaned aluminum surface to the first coat of primer. That is where the Zinc Chromate comes in, as well as self etching primers too. Then you use a quality primer over that. Then you sand any issue smooth and you are ready for paint and even clear coats if that is the way you chose to go. So when painting aluminum, there are actually two different types of primer used before paint is applied. JMHO