Spraying enamel

[mhorowit]

I'd like to spray some enamel as a top coat for my fuselage.
Any suggestions for dilution? - Mike

[Hank Jarrett]

Re: Spraying enamel

If you are talking about the FABRIC, just use something that makes it easy to remove later. I never had any luck with enamel on fabric. If you are talking about the metal parts just stay with the same brand materials. The only time I had problems was when I used one brand of paint and another of thinner. They were supposed to be chemically identical, but mixing brands did NOT work. I think the paint companies slip a little something in to keep you from mixing brands.
Hank

[d.grimm]

Re: Spraying enamel

Check the manual for your covering process. I don't believe you are allowed to overcoat with non-system products. This is a fairly new requirement.
Dave

[Hank Jarrett]

Re: Spraying enamel

Any idea where that requirement is published? It used to be that they didn't care what you put on cosmetically if the fabric was protected by a certified product series. You could do Nitrate and Buterate dope over the fabric through silver and use house paint after that. If the color blew off the plane was UGLY but not unsafe.
Hank

[magman]

Re: Spraying enamel

Most ( NOT AirTech though) STC holders modified their requirements after the

ALLEGED fabric separation on Steve Wittman's " O & O Special".

I've always considered enamel over fabric to be a cheap job that is done only when you're trying to sell a dog.

The fabric/dope & the enamel expand & contract at different rates with

temperature. This leads to cracking & peeling.

No problem if the aircraft is always indoors.


Difficult to patch over enamel as well.

[mhorowit]

Re: Spraying enamel

Most ( NOT AirTech though) STC holders modified their requirements after the

ALLEGED fabric separation on Steve Wittman's " O & O Special".

I've always considered enamel over fabric to be a cheap job that is done only when you're trying to sell a dog.

The fabric/dope & the enamel expand & contract at different rates with

temperature. This leads to cracking & peeling.

No problem if the aircraft is always indoors.


Difficult to patch over enamel as well.

Nope - this is enamel over the primer on the fuselage - Mike

[Guest]

Re: Spraying enamel

I'd like to spray some enamel as a top coat for my fuselage.
Any suggestions for dilution? - Mike

read the STC for your fabric covering (if you are using one) before you do that

you may be required by the stc to use a specific enamel (like epoxy)

[N96337]

Re: Spraying enamel

Mike,
As to your original question: Whatever brand of enamel you use, will have specific instructions as to mixing. Follow them to the letter! People who tell you to modify mixing instructions, or who tell you they can tell how well a paint is mixed or diluted "just by the look" are full of BS! The paint you use has had a specialist experiment with different dillutions and mix rates, and the one they include in their "tech sheets" is the one to use.

As far as the FAA and rule changes... In the late 90's or early 2000's, the FAA changed the ruling that all fabric covering processes are to be completed in strict accordance to the STC owner's manual all the way through topcoat. This brought a revision to all the systems' manuals out there. Basically this means that you have to follow one process and have PMA'd products all the way through top coat. It used to be that the covering process was only specified up through the UV protectant. So, what this means is that you can't go down and buy automotive paint and use it to put a top coat on your fabric covered, certificated aircraft. You CAN use whatever you want on the metal parts, just not the fabric. There were getting to be alot of failures that were blamed on one system or another, when it was actually the top coat that was failing and causing the problem. Even if you have an aircraft (certificated, not experimental) that was covered long ago and they used a non-certified topcoat (such as Imron or something along that nature), you cannot legally repair it with the same topcoat anymore. That being said, you can go over that with Stewart's System legally, if I'm remembering correctly. (Jason, you still around?) It's one good change the FAA has done to existing rules, in my opinion.
John

[Pearson]

Re: Spraying enamel

Mike

Some points to ponder regarding your original question; as several others have mentioned, the way to mix the paint is per the manufacturers instructions. You can buy graduated mixing cups that will help greatly with getting the proper mix ratio.

A couple of other points to think about - are you going to finish your fabric with a polytone type of paint (flat or satiny finish), or are you going to use a urethane with a high gloss? If you use the polytone, you will have a high gloss on the metal parts and a dull look on the fabric. You can use enamel on the metal, but need to add a "flattening agent" to match the sheen of the polytone. How much you add affects how flat the enamel looks.

Some of the recovering systems allow you to use the same paint on the metal as the fabric. The metal parts will have a slightly different hue, but will be very close to the same as the fabric. I know Air Tech Coatings used to do this.

[Guest]

Re: Spraying enamel

Mike,
As to your original question: Whatever brand of enamel you use, will have specific instructions as to mixing. Follow them to the letter! People who tell you to modify mixing instructions, or who tell you they can tell how well a paint is mixed or diluted "just by the look" are full of BS! The paint you use has had a specialist experiment with different dillutions and mix rates, and the one they include in their "tech sheets" is the one to use.

As far as the FAA and rule changes... In the late 90's or early 2000's, the FAA changed the ruling that all fabric covering processes are to be completed in strict accordance to the STC owner's manual all the way through topcoat. This brought a revision to all the systems' manuals out there. Basically this means that you have to follow one process and have PMA'd products all the way through top coat. It used to be that the covering process was only specified up through the UV protectant. So, what this means is that you can't go down and buy automotive paint and use it to put a top coat on your fabric covered, certificated aircraft. You CAN use whatever you want on the metal parts, just not the fabric. There were getting to be alot of failures that were blamed on one system or another, when it was actually the top coat that was failing and causing the problem. Even if you have an aircraft (certificated, not experimental) that was covered long ago and they used a non-certified topcoat (such as Imron or something along that nature), you cannot legally repair it with the same topcoat anymore. That being said, you can go over that with Stewart's System legally, if I'm remembering correctly. (Jason, you still around?) It's one good change the FAA has done to existing rules, in my opinion.
John

Hi John,

The part in red above is incorrect.

Some STCs specify the metal enamel as well. By metal I mean the tubing in the airframe.

Maybe you mean other metal parts??

I have one STC like that in my file right now.

You must read fully the STC and understand it.

Dave

[Mark Julicher]

Re: Spraying enamel

Nope - this is enamel over the primer on the fuselage - Mike

Bad idea Mike.
Fabric cement will lift the enamel. Not an approved nor healthy procedure.

[Edwin Otha]

Re: Spraying enamel

Mike,
Any enamels used around the fuselage need to be a catylized enamel. All of the covering systems except Stewarts System will lift the standard enamels.
EO

[mhorowit]

Re: Spraying enamel

Bad idea Mike.
Fabric cement will lift the enamel. Not an approved nor healthy procedure.

OK; I"m using Stewart, but just in case the next guy doesn't read the logbook carefully... . So, what would you recommend from HomeDepotAerospace as a top coat? any of the polyurethanes? - Mike

[TonyL]

Re: Spraying enamel

The STC - supplemental Type Certificate is an airworthiness order. If your Acft is standard category, you should adhere to it. Ceconite requires, 101 or 102 fabric, in order to meet the standard category. 103 can be used n experimental only. The process is this, Nitrate, - highly flammable, only dope that adheres to fabric. Then Butyrate - which by virtue of chemical reaction mixes with the nitrate for adhesion. Then Butyrate silver - which is your UV )ultra violet protection. - then top coat of colored butyrate or Ranthane - which is a polyurethane based top coat. All of these must be non tauntening. Otherwise, it will shrink and warp your wings. I think I have a copy of Ceconite 101 on my computer send me an E mail. I'll attach it send it to you. The latest version of the STC is dated 2007. If you have to file a 337 form. for the process, the foundation has copies. The problem is, you are telling them, that you adhered to the STC. TonyL [email protected]

[Guest]

Re: Spraying enamel

OK; I"m using Stewart, but just in case the next guy doesn't read the logbook carefully... . So, what would you recommend from HomeDepotAerospace as a top coat? any of the polyurethanes? - Mike

no polyurthanes, use epoxy, epoxy is called out in at least one STC, maybe brushing is better?