Firewall angle painting

I don't want to get into a discussion of whether or not to paint the angles at all. That is a different topic. I'm still thinking about that one.

My question is can the firewall stiffeners even be seen when the interior is completed. I mean without standing on your head.

I'm curious what others did that did decide to paint the angles. Did you just prime or did you prime and topcoat with the interior paint?

Firewall Angle Painting

I exoxy primed and Jetflex WR painted all my aluminum firewall parts (not the stainless steel parts) prior to riveting. All the rest of my interior was painted this way so:
1. It all matches.
2. The exposed aluminum is protected from corrosion.
3. The aluminum and stainless are separated from each other against dissimilar metal corrosion.

I would never paint the stainless firewall, but I'm not worried about the paint on the firewall angles or the floor or side skins. If it's hot enough to burn that paint, I've got bigger problems than fumes.

Terry,

Thanks for the input. I was thinking along the same lines.

terrye said:

I exoxy primed and Jetflex WR painted all my aluminum firewall parts (not the stainless steel parts) prior to riveting. All the rest of my interior was painted this way so:
1. It all matches.
2. The exposed aluminum is protected from corrosion.
3. The aluminum and stainless are separated from each other against dissimilar metal corrosion.

I would never paint the stainless firewall, but I'm not worried about the paint on the firewall angles or the floor or side skins. If it's hot enough to burn that paint, I've got bigger problems than fumes.

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Same here (but used automotive paint that was color-matched to the Van's light grey powder-coat). Looks good, and yes, you can see some of these items when seated in the cockpit, so painting them made for a nice "finished" look.

All were primed. The ones that will be visible were painted. The rest remained with only primer with exception the top skin - I plan on painting it a light/white color for better visibility under the panel.

Just to add some clarity, SW Jetflex both WR and Solvent based "Interior" paint is designed to address the burn/smoke/fumes concerns that some folks seem to be worried about.

If you are truly worried about any materials exposed to the interior giving off toxic fumes or contributing to a cabin fire, make sure they are tested to and meet the requirements of FAR 25.853.

Designed to meet FAR/JAR 25.853 regulations for burn, smoke and heat release - See more at: http://www.swaerospace.com/products/brands/jetflex/#sthash.xzKNZmMl.dpuf

Ken Martin said:

Just to add some clarity, SW Jetflex both WR and Solvent based "Interior" paint is designed to address the burn/smoke/fumes concerns that some folks seem to be worried about.

If you are truly worried about any materials exposed to the interior giving off toxic fumes or contributing to a cabin fire, make sure they are tested to and meet the requirements of FAR 25.853.

Designed to meet FAR/JAR 25.853 regulations for burn, smoke and heat release - See more at: http://www.swaerospace.com/products/brands/jetflex/#sthash.xzKNZmMl.dpuf

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Clarity eh?

Read Appendix F, the test procedures related to 25.853. They have no relevance to a hot firewall. None. Zip. Zero.

A 25.853 claim means it is a good paint for the interior cabin sidewalls, tailcone, etc.

DanH said:

Clarity eh?

Read Appendix F, the test procedures related to 25.853. They have no relevance to a hot firewall. None. Zip. Zero.

A 25.853 claim means it is a good paint for the interior cabin sidewalls, tailcone, etc.

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I'm not sure if you were interpreting my post as condoning painting the SS firewall or not? Just to make clear; I was not. I'm speaking in regards to the attached angles.

Seriously, if there is manufacturer or government backed test data to show that Aerospace coatings meeting FAR 25.853 specifications will give off toxic fumes or somehow contribute to fueling a fire more so than other components attached to the firewall in this type of application, I would truly like to see it.

The only inference I can make for my own piece of mind is between FAR 25.853 and FAR 25.867 below. I interpret this to mean that the FAA believes that materials used outside of a firezone, (in this case aft of the firewall/engine nacelle) must be at least fire resistant. From my experience, that's part of what the burn tests determines.

The closest I have found so far addressing this is FAR §25.867 Fire protection: other components.

(a) Surfaces to the rear of the nacelles, within one nacelle diameter of the nacelle centerline, must be at least fire-resistant.

(b) Paragraph (a) of this section does not apply to tail surfaces to the rear of the nacelles that could not be readily affected by heat, flames, or sparks coming from a designated fire zone or engine compartment of any nacelle.

Ken Martin said:

I'm not sure if you were interpreting my post as condoning painting the SS firewall or not? Just to make clear; I was not. I'm speaking in regards to the attached angles.

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My objection is specific; 25.853 is not an appropriate materials standard for anything in contact with a hot firewall.

FAR 25.853 is a standard for transport category cabin walls, baggage floors, seat upholstery, plastic panels, etc. Open flame burning of an 25.853 material is not a test failure when in contact with the heat source, and it is allowed to smoke, fume, melt, and drip. The basic pass/fail criteria is that it stop burning and dripping within 15 seconds after the heat source is removed. Think little Johnny in the lav with his daddy's Bic lighter.

Here's what happens when you put an FAR 25.853 material in contact with a test firewall subjected to 25 sq at 2000F. This is Orcotek (http://www.orcon-aerospace.com/orcotek.htm), a legitimate cabin wall insulation that you probably fly with in the big jet:



Anyway, if 25.853 compliance is so grand, why do they issue smoke hoods to flight crew?

The only inference I can make for my own piece of mind is between FAR 25.853 and FAR 25.857 below.

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I'm not buying tickets on your airline if they make passengers ride in the nacelles

Seriously, you're in the wrong Part. See FAR 23.1182.

Dan,

I have no desire to get into an aircraft design argument with a self-proclaimed aerospace engineer. Your unnecessary condescending responses to an open discussion on this topic are over the top.

The PBE "smoke hoods" you mention assist crews who have to deal with potentially MUCH more severe scenarios from altitudes much higher (read-longer emergency decent times) then what we are dealing with.

These unscientifically controlled tests in your backyard with assentially a blow torch placed against material to see how soon they will burn are entertaining at best. This is not a realistic test for our application, but I'm sure your "Engineering" degree gives you enough imagination to create the scenario that is statistically improbable.

So let's just agree to disagree, and move on. You can save your snarky comments as I much prefer to have civil discussions with fellow aviation enthusiasts

Ken, I'm sorry that you feel besieged enough to go personal, but the facts remain. Please don't declare 25.853 materials to be safe in contact with a firewall

Let's just agree to disagree, and move on.

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Fair enough.

From the sidelines, with popcorn, I enjoy Dan's common sense tests, no need for multi million dollar test equipment, just a way to measure temps, simulate an engine fire, wa la! Data! Coming from a background of auto, truck, marine and Drag racing, I have seen my share of oil and gas fires. It is just amazing how fast and instantaneous a small oil leak self ignites on hot headers! let alone one under pressure, Go from a nice peaceful blue sky day to blow torch self destruction in milliseconds, just like Dan's test rig!

bret said:

From the sidelines, with popcorn, I enjoy Dan's common sense tests, no need for multi million dollar test equipment, just a way to measure temps, simulate an engine fire, wa la! Data! Coming from a background of auto, truck, marine and Drag racing, I have seen my share of oil and gas fires. It is just amazing how fast and instantaneous a small oil leak self ignites on hot headers! let alone one under pressure, Go from a nice peaceful blue sky day to blow torch self destruction in milliseconds, just like Dan's test rig!

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Again, I'm going to speak about the "specific" application of small amounts of Fire Resistant paint applied to Aluminum angles riveted to the firewall outside of the firebox -- of a GA type aircraft. (I qualified my statement before, but just in case someone want's to use my words as a blanket statement for all applications.)

Aluminum turns to liquid before reaching 1250F. You do a "Common Sense" test using 2000F flame and are more worried about the paint than the substrate it is adhered to???

With my 20+ years of Aeronautical Engineering experience, I have to agree with a previous poster who stated, (and I summarize) "If my aircraft is reaching those temps, I have bigger concerns to worry about."

rapid_ascent said:

I don't want to get into a discussion of whether or not to paint the angles at all. That is a different topic. I'm still thinking about that one.

My question is can the firewall stiffeners even be seen when the interior is completed. I mean without standing on your head.

I'm curious what others did that did decide to paint the angles. Did you just prime or did you prime and topcoat with the interior paint?

Click to expand...

I went with water-reducible primer and JetFlex top coat, to match the rest of the interior:

right or wrong, I had primed all my firewall angle with a self-etching primer prior to assembly. When I painted the interior, I masked off the firewall and shot the whole thing with a coat of epoxy primer and then urethane topcoat. I'm happy with the results. The epoxy and topcoat are both PPG Products.

Topcoat is PPG Omni MTK. I have been very happy with the paint in this application. It is a single-stage urethane. The coverage was great and even shooting at odd angles and tight spaces with my cheap gun and inexperienced hand, I only got one small run in a place that can't be seen anyway.

Doug,

Thanks for the pic. I think that is what I'm going to do. Did you use Jetflex WR? Your paint color looks about like what I was looking for. What color is it?

Hi Ray,

Yes, it is JetFlex WR. Very easy to use, and the fumes are not bad at all. I'm not sure what the color code is, but the color is called Gray Beige.

Here's another overall/panel shot of the interior to give you a better idea of how it looks:

Doug,

I think that color looks nice. I ordered a color chip card from Alliance yesterday so soon I hope to be able to make my selection. Bruceh used that color also and he had lots of pics. It hard to be sure of the color on a computer screen. I'm trying to match the Ash leather from Classic Aero so I'll see how it goes.

I think you'll like it. I wanted a neutral color, on the lighter side for a nice airy feel in the cockpit. I like to see contrast between the darker forms of the EFIS, dials, etc. and the panel.

It's not the most durable paint in the world, but super easy to apply, and a cinch to touch up...I use one of those sponge-type brushes and just dab it on. When dry, it's nearly impossible to see where original paint ends and touch-up begins.