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Permalink Reply by Joe Hopwood on December 17, 2017 at 6:06am

I suspect it is no longer available as zinc chromate paste.  Zinc Chromate is highly toxic but if you google it you will find a wide variety that is available both in spray can and in liquid form.

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Permalink Reply by Michael T. on December 17, 2017 at 7:27pm

Aircraft spruce had both spray cans and liquid versions of zinc chromate. But I wanted to try the paste version and compare results. 

If anyone has a link or source they can share. Much appreciated

Michael

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Permalink Reply by John Austin on December 20, 2017 at 7:34am

Michael,

Have you considered Cortec?  It's non-toxic (unlike zinc chromate) and dilutes with water.  Zenith should have it available in quart-sized cans.

John

N750A

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Permalink Reply by Michael T. on December 27, 2017 at 4:38am

I`m trying not to bug the factory with a ton of newbie questions, thusly I`m posting here

What is Zenair painting on plane parts/spars currently at the factory, is it zinc chromate or Cortec?

there are so many philosophies when it comes to primer, varying from RV guys who lather it on everything to Zenair who applies it only where it counts.

As an ex RV guy I`m familiar with the RV way, now I`m trying to understand the Zenair way.

Still trying to source the zinc chromate primer paste Ive heard about so many times, maybe its Cortec? and its being referred to as zinc chromate and causing this confusion.

Michael in Toronto

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Permalink Reply by Ken Ryan on December 27, 2017 at 9:06am

2024 aluminum is more subject to corrosion than 6061 (that's why they put a pure aluminum layer on thin sheets). 6061 is less subject to corrosion. There is no 2024 used on the Zeniths. I think that is why many Zenith builders are comfortable with priming only the mating surfaces. The environment the airplane will operate in is important. Salt water, high humidity etc. will be a more corrosive environment than dry desert air. How long you expect the airplane to last is a consideration. If you are building it to last "forever" that's different than an expected life of 15-20 years.

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Permalink Reply by Lawrence Bird on January 2, 2018 at 12:48pm

If you're set on zinc chromate, try the marine world -- also; Amazon has the ZC by the gallon the last I checked... not sure about the paste that used to be available -- everyone says it's toxic, it is... but in the marine world, that's what it's supposed to be... A few years ago I bought up a bunch of aerosol cans of the primer at $6-7 a can, now they are over twenty for the same can, so if it were me on 6061, I'd look for something a tad less...

 

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