Gear Leg Sockets - Corrosion Protection?

[David Paule]

Having just gotten my finish kit, I'm wondering about my bare-metal engine mount. I don't want it to rust so I guess I'll have it painted with a high-temp paint. The RV-3B uses round-bar landing gear legs in the engine mount sockets. And it'll be a couple years before I get far enough to install all this.

But what about the gear leg sockets? What do you do about them? Paint or grease or?

And that brings up the gear legs. Any recommendations? Eventually I'll be installing the gear-leg stiffeners so I don't want to preclude good adhesion to them.

One thing I won't do is powder-coat any of them. My Cessna 180 has powder-coated engine mount and gear legs and for both, the long-term performance has proven unsatisfactory.

Dave
RV-3B, now on wings and tanks and things

[ArlingtonRV]

Originally Posted by David Paule

My Cessna 180 has powder-coated engine mount and gear legs and for both, the long-term performance has proven unsatisfactory.

David, please elaborate on the unsatisfactory performance. I believe that most of the other models of RV engine mounts are powder coated as are Glastar / Sportsman engine mounts. What exactly was unsatisfactory?

Thanks

[David Paule]

The engine mount in my Cessna 180 was powder-coated when I replaced the engine 500 hours ago. Since then it has significantly discolored due to the heat.

The landing gear legs were powder-coated at the same time. Now please remember that on the Cessna 180 they aren't in fairings like on the RVs. They're exposed. The paint has cracked and chipped and in a few places, peeled off. While some of the smaller paint dings were from gravel chips, the bigger ones weren't.

In both cases, they were painted with appropriate primers and paints.

Also, just for the record, some time ago I'd said that the baffles, which were powder-coated white, were holding up perfectly. They aren't. Now they are peeling in two places.

All in all, I'm not pleased with the powder-coating experience I had. I expected better service life.

The RV-3B engine mount and gear legs arrived bare. I'd like to keep them from rusting, so I'm looking for recommendations for that, especially for the socket area.

Dave

[Andy Hill]

Hi Dave

As you say, exterior of engine mount I'd just use a light coloured high temp durable paint (we have).

Inside the gear leg sockets, I'd very lightly prime for protection, then grease. Nothing of any substance or the gear legs won't fit!

Gear legs - left mine rather too long and needed a good rub down, now a good etch prime on them. No idea how that will affect adhesion if/as/when put gear leg stiffners on. Again, any paint / primer on the parts on the gear leg sockets will have to come off, so grease the best anti-corrosion between now and fitting...

Powder Coat seems fine when someone else (e.g. Vans) provides it and done properly - but not sure anything I have in bare metal I'd go to the bother... Some do not like powder coat on an engine mount since it can hide cracks.

[Tbone]

In both cases, they were painted with appropriate primers and paints

I did powder coat professionally several years back and never seen a "primer" for powdercoat. It was not needed. If material was prepped correctly you wouldn't see any peeling at all.

I use a product called Mastonox. We use it for corrosion protection on our helicopters at work. Nothing better in my opinion .

[9GT]

I coated the sleeves and the legs with with silver anti-seize prior to insertion for final assembly.

[az_gila]

Originally Posted by Tbone

In both cases, they were painted with appropriate primers and paints

I did powder coat professionally several years back and never seen a "primer" for powdercoat. It was not needed. If material was prepped correctly you wouldn't see any peeling at all.

I use a product called Mastonox. We use it for corrosion protection on our helicopters at work. Nothing better in my opinion .

I had some RV steel parts powder coated by an outfit in the LA area that did aerospace work for the big manufacturers.

They used a Mil-P-23377 epoxy primer (Akzo-like) as a matter of course after bead blasting.

With their giant, open flame drying ovens that looked like the gates of Hades, the extra painting step went quickly.