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Factory Corrosion Protection

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Factory Corrosion Protection

If one is interested in an older 182, 185, or 206 how can you tell if it came with the float kit/package and factory corrosion protection?
Last edited by Cooperd0g on Sun Feb 07, 2016 9:53 pm, edited 1 time in total.
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Re: Factory Corrosion Protection

Factory corrosion proofing is usually zinc chromate primer (green or yellow) on the inside of aircraft structure vs bare alclad aluminum. Float kits are various doublers and extra internal structure to strengthen around load paths at float attach points. Also additional hardware. ( lifting eyes, water rudder pulleys and assorted brackets) Different models have various setups. As a general rule, older lighter gross weight airframes have less extra doublers vs later models with high gross weight have extensive beefups with many more parts for more durability.
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Re: Factory Corrosion Protection

Ok, thanks. So if isn't mentioned in an ad, then it can be asked and should be able to be verified with pictures before doing any travel to look at a prospective plane. Does that sound about right? Is there any way to verify by serial number or anything like that?
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Re: Factory Corrosion Protection

Factory corrosion-proofing would be a non-standard feature, at added cost and with added weight, so I wonder if the original factory equipment list would include it?

A "float kit" is indeed as Rockhopper described, but it is my understanding that (at least on early models) a factory float kit on a new airplane included the zinc chromate treatment in between lapped skins, as well as inside the fuselage.
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Re: Factory Corrosion Protection

Cooperd0g wrote:Ok, thanks. So if isn't mentioned in an ad, then it can be asked and should be able to be verified with pictures before doing any travel to look at a prospective plane. Does that sound about right? Is there any way to verify by serial number or anything like that?


If you have the serial number of the airframe, you MAY be able to get a build sheet from Cessna....maybe. But, it's easy enough on older Cessnas to verify by simply looking inside the wings or at the inside of the fuselage aft of the baggage. If it has the OD green zinc chromate inside the skins, it was corrosion proofed. Later on, Cessna used a yellow zinc chromate paint.

All float kit Cessnas were corrosion proofed.

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Re: Factory Corrosion Protection

mtv wrote:...it's easy enough on older Cessnas to verify by simply looking inside the wings or at the inside of the fuselage aft of the baggage. If it has the OD green zinc chromate inside the skins, it was corrosion proofed. Later on, Cessna used a yellow zinc chromate paint.....


Maybe , maybe not. I know of a number of airplanes that were zinc-chromated inside as part of a rebuild or repair or just a general sprucing up. I may be mistaken, but as I understand it, Cessna zinc-chromated the inside of the skins before assembly, so that it's in between the lapped joints- which is where corrosion often starts. Sprayed onto the interior of the fuselage after assembly is still good, just not as good.
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Re: Factory Corrosion Protection

hotrod180 wrote:
mtv wrote:...it's easy enough on older Cessnas to verify by simply looking inside the wings or at the inside of the fuselage aft of the baggage. If it has the OD green zinc chromate inside the skins, it was corrosion proofed. Later on, Cessna used a yellow zinc chromate paint.....


Maybe , maybe not. I know of a number of airplanes that were zinc-chromated inside as part of a rebuild or repair or just a general sprucing up. I may be mistaken, but as I understand it, Cessna zinc-chromated the inside of the skins before assembly, so that it's in between the lapped joints- which is where corrosion often starts. Sprayed onto the interior of the fuselage after assembly is still good, just not as good.


Yes, back in the day, Cessna riveted skins after corrosion proofing.

The OP is asking how to tell if the plane was corrosion proofed. So, you're saying that you'd pass up an otherwise perfectly good airplane because it was corrosion proofed AFTER it was assembled, vs during assembly?

If it's an early Cessna with a float kit, it will have certain features, as others have noted. These MAY include lift rings, aft float block attach points, a windshield V brace, etc. But, there aren't many old Cessnas without a float kit that were zinc chromated after the assembly.

FWIW, it is a real bitch to try to paint the insides of wings/fuselage, tail feathers, etc.

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Re: Factory Corrosion Protection

Cooperd0g wrote:If one is interested in an older 182, 185, or 206 how can you tell if it came with the float kit/package and factory corrosion protection?


Short of having the plane's original owner's delivered paper work, you have to look at the plane. My current 185 has all the paper work and lists out the weights of each option....but none of my other 180's came with that documentation. Luck of the draw.

As people have said, a 180/185 (not sure about 182/206) will have doublers around the potential float attach points. They'll also have provision for a windshield brace (not necessarily installed), rudder/aileron interconnect in later planes, strut steps/fueling steps and handles.

Unfortunately, many of the items above can be added after the fact, but you have to take the system as a whole I guess.

As far as the corrosion proofing, I'd have the seller take pictures in the hard to get places to look for zinc chromate. Many of the nooks and crannies would be hard to spray in after the fact so look in the flaps, trailing edges, floor boards, etc. Also...it may be intuitive but there were lots of planes ordered with corrosion proofing that did not have float kits. it was an option.

I've seen several non-float kitted 185's with corrosion proofing and all of the ag-carry all's I've seen were corrosion proofed. Don't know if that's the whole population though.

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Re: Factory Corrosion Protection

mtv wrote:.....The OP is asking how to tell if the plane was corrosion proofed. So, you're saying that you'd pass up an otherwise perfectly good airplane because it was corrosion proofed AFTER it was assembled, vs during assembly?.....


Read the OP-- he asked about "factory corrosion protection".
Like I said, chromated after assembly is good, just not as good.
My own 180 is only chromated here and there inside, so I guess I'm not too picky.
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Re: Factory Corrosion Protection

Cooperd0g wrote:If one is interested in an older 182, 185, or 206 how can you tell if it came with the float kit/package and factory corrosion protection?


To your specific question:

First of all, there is no such thing as a "float kit" on a Cessna 182. Cessna has never approved nor installed a C-182 on floats. All the 182s that are out there on floats now were done via STC by an after market modifier. All 182s that came out of the factory were wheel planes.

On the 185 and 206, it depends somewhat on the model year.

What are you trying to identify....whether the airplane has a float kit, or just whether it was corrosion proofed at the factory? When you get ready to look at a specific airplane, post the model, the year, and SPECIFICALLY what you want to know.

And, hiring a competent mechanic who is very familiar with the type to do a pre-buy is mandatory if you're thinking about buying one of these things.

General questions like this don't have a simple answer.

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Re: Factory Corrosion Protection

Thanks for the responses. I did not realize that 182s never came set up for floats from the factory. Mostly I was just looking for general guidance. I seem to be perpetually "a few years away" from buying a plane, but I will vet any potential purchase thoroughly when the time comes.
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