"red oxide primer is a plus"

I was working with an A&P while he did a pre-purchase for me.
He looked at the inside and remarked that 'red oxide primer is a plus".
Can someone elaborate? what's it better than?- Mike

mhorowit wrote:
I was working with an A&P while he did a pre-purchase for me.
He looked at the inside and remarked that 'red oxide primer is a plus".
Can someone elaborate? what's it better than?- Mike

Red oxide primer on what? On steel, its a plus. It's kind of "pre-rust",
and helps to protect steel parts from further corrosion, to a limited
extent. On aluminum (or magnesium, God forbid)it will promote corrosion
(do a Web search on the galvanic series), and is a definite no-no.

Rip

On Fri, 18 Nov 2005 00:13:25 GMT, Rip
wrote:

mhorowit wrote:
I was working with an A&P while he did a pre-purchase for me.
He looked at the inside and remarked that 'red oxide primer is a plus".
Can someone elaborate? what's it better than?- Mike

Red oxide primer on what? On steel, its a plus. It's kind of "pre-rust",
and helps to protect steel parts from further corrosion, to a limited
extent. On aluminum (or magnesium, God forbid)it will promote corrosion
(do a Web search on the galvanic series), and is a definite no-no.

Rip

Rip - 4130 - Mike

I've seen red oxide on aluminum and wondered wth put it on there.
Zinc chromate is the aircraft builder's and owner's best bet for
aluminum, magnesium, or chromoly.

If I were welding up a fuselage of 4130, I'd powdercoat it. The old
ones I see which are well-preserved are painted with zinc chromate and
then injected with boiled linseed oil.

I agree with this writer:

http://www.paintcenter.org/rj/feb05d.cfm

Michael Horowitz wrote:
On Fri, 18 Nov 2005 00:13:25 GMT, Rip
wrote:


mhorowit wrote:

I was working with an A&P while he did a pre-purchase for me.
He looked at the inside and remarked that 'red oxide primer is a plus".
Can someone elaborate? what's it better than?- Mike


Red oxide primer on what? On steel, its a plus. It's kind of "pre-rust",
and helps to protect steel parts from further corrosion, to a limited
extent. On aluminum (or magnesium, God forbid)it will promote corrosion
(do a Web search on the galvanic series), and is a definite no-no.

Rip


Rip - 4130 - Mike

4130, no harm, no foul.

Rip

JLS - powdercoating. I've seen several comments discouraging use of
powdercoating as it hides cracks.YMMV - Mike

"mhorowit" wrote in message
oups.com...
JLS - powdercoating. I've seen several comments discouraging use of
powdercoating as it hides cracks.YMMV - Mike


Depends. Here in the land of over-regulation, powdercoating isn't allowed
unless it can be proved to crack when the surface of the underlying material
cracks. Having tested several types, I'm pretty much convinced that the
hard polyester powder coats are fine. So are our CAA, who permit them on
aircraft structures, engine mounts etc.

The nylon ones definitely aren't OK though. I'm pretty sure that cheap
nylon podercoat is what's used on domestic garden goods, the sort where rust
bubbles up under the coat after a few years.