The green stuff is zinc chromate, right?

[mhorowit]

The green coloring over the tubing is zinc chromate, correct?

I see where it's sold in spray cans.

I'm thinking of removing some rust with a non-abrasive pad, then spraying on zinc chromate.

The original zinc chromate coating has lasted 60 years; why should I bother with a modern primer i.e. 2 part epoxy?

If I followed my plan, would I interfere with a different primer should my A&P not like what I've done? - Mike

[Robert Lees]

Re: The green stuff is zinc chromate, right?

You SHOULD bother with a modern 2-pack primer, because modern adhesives (poly-Tack, Superseam, etc) will remove single-pack primer. This will lead to premature corrosion.

You can overcoat old z-c primer with 2-pack if necessary.

Have a read of Priming of steel-tube airframes on another forum I frequent.

60 years ago they used dope to adhere cotton or linen. Now you cannot.

[mhorowit]

Re: The green stuff is zinc chromate, right?

Alright! I was a bit worried that some time might elapse between my removing rust and getting it primed properly; so I'll protect the metal with ZC and let my A&P prime it with 2-part. Thanks - Mike

[robbie]

Re: The green stuff is zinc chromate, right?

Mike,
When spraying ZC use a good mask, It's bad stuff to breath

[mhorowit]

Re: The green stuff is zinc chromate, right?

Mike,
When spraying ZC use a good mask, It's bad stuff to breath

Is spraying in the open an acceptable substitute? Are you talking about a simple dust mask or something based on a carbon filter?- Mike

[Robert Lees]

Re: The green stuff is zinc chromate, right?

ALL spraying is bad stuff...so a carbon filter as a minimum. This should be good enough for open-air.

[flyguy]

Re: The green stuff is zinc chromate, right?

Not only will the cement lift and ruin chromate primer, but so will the solvents in any of the modern fabric covering coatings.
Darryl