Zinc Chromate vs Zinc Phosphate?

[Desert Rat]

For rattle can, do you guys prefer chromate or phosphate? Phosphate wasn't a thing when I went through A&P school approximately 1,000 years ago.

 

[tgmillso]

The short answer is if you want the ultimate corrosion protection and don't care about a dose of hexavalent chromium and the subsequent cancer it causes, then zinc chromate is your weapon of choice. If you do care, then zinc phosphate is the next best option rattle can wise. If you dig through the archives there's plenty discussing both and some recommendations on quality zinc phosphate options.

Tom.
RV-7
Zinc phosphate (Wattyl/Valspar Superetch) and EkoPoxy

 

[Charles in SC]

I am not sure about the chance of cancer is but I have used both. My take is the phosphate covers a little better but when you study some of the past success with chromate it is pretty impressive. I like using chromate but I try to stand upwind to prevent cancer.

 

[scsmith]

And it is not like the hexavalent chromium suddenly vanishes after you use it either -- it spreads out into the environment at large, and propogates a trail of death.

In terms of really toxic, nasty things to put into the environment, I would rank:

1) Plutonium

2) Dioxin

3) Hexavalent Chromium

4) DDT

....lots of other stuff.

This is why I've avoided using Alodine also.

 

[mike newall]

Avoid chromate at all costs, it is just not necessary. As a heavy metal, it builds within your system and is not excreted.

The protection from non chromated rattle can and spray primers with correct prep and de greasing is just fine. The base alclad is good enough - our priming just belts and braces it and gives peace of mind.

More protection is provided with ACF50 or Corrosion X after completion and painting.