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Firewall insulation

Welcome to VAF!!!!

Karl, welcome to the good ship VAF.:D

There is a lot of information on firewall insulation on the forum already, one of the members has done a lot of research and testing on various materials.

Search for "firewall insulation" using the search function, pretty much anything by Dan H will be good info for you to look at.

Good luck, and again, welcome.
 
Karl, give me a call. I got a source for a enough Firewall insulation(FAA approved) for 5 planes. Might even get it delivered for free, as I have to bring the roll back to Helena one of these days.

Brian
980-1193cell
 
Search the threads....

DanH did a bunch of research and testing . Before I would venture into what sounds like a very simple process, I would review his hard work.
 
DanH said:
Brian, which FAA standard does it meet?
Click to expand...

Dan, below is info I got

Flammability Requirements
All materials meet FAR 25:853 (a), Appendix F, Part 1 (a) (1) (ii) for flammability. Certificate provided with each kit or bulk order.

I don't know if this passes your tests, but for me it's good enough.
 
Brian,
Did you put your firewall insulation on the forward side of the firewall, or the aft side?

I'm potentially interested in some of your extra material, too, before you take it back.
 
aft of the Stainless.

I don't think it would work well in the engine compartment.

It's not my material, a guy redoing his cub bought to much and is selling it to me. I'll probably end up paying him for what I use at the same rate he bought it for. I'll save shipping and waste $$'s
 
hydroguy2 said:
All materials meet FAR 25:853 (a), Appendix F, Part 1 (a) (1) (ii) for flammability.
Click to expand...

That's what I thought. You're offering airliner cabin wall insulation, not firewall insulation. It is fine stuff for insulating wall panels well aft of the firewall, but totally inappropriate for contact with the firewall itself.
 
All I'm going by is the advertisement which says Firewall certified and the stated info that some certified planes are using it in the same location.

We all have levels of risk we are willing to accept. If my firewall gets hot enough to cause this mat to be a problem I most likely already have a huge issues to deal with. My aluminum heatbox, pass thru's, rubber & plastic grommets and wiring will already be trying to kill me. YMMV

It's not my material to sell anyway, so never mind Karl....you can still call me if you want to talk RV's or something.
 
hydroguy2 said:
We all have levels of risk we are willing to accept. If my firewall gets hot enough to cause this mat to be a problem I most likely already have a huge issues to deal with. My aluminum heatbox, pass thru's, rubber & plastic grommets and wiring will already be trying to kill me. YMMV
Click to expand...

Being a furnace guy, such that I am; and looking at flames on a daily basis................it's my feeling also. If something is capable of putting out a 2000 degree blast at my firewall, then I've really got problems, such as a cowling & windscreen. Other than that, the main source of fuel, will be turned off at the fuel selector.

L.Adamson --- RV6A
 
Dan, I appreciate your hard work and testing in this area, but:

The material I have came from a friend, I didn't buy it and I'm comfortable with my choice. It may or may not perform well in your tests and I don't need rake over the coals. So at this time, I respectfully decline.
 
Brand?

Hydroguy,

For those of use doing our own research, could you provide the brand name of the material you used. Not all of us what ceramic tile protection between us and the firewall and it would be nice to know of as many type of products available out there.

I am sure there are many that will read this post that would appreciate another product to consider. Don't mind the flames (pun intended) that you might get from the forums, a good pilot needs a thick skin.

I have already bought some material that is fiberglass with a PVC type cover, it is the stuff used to line the walls in military transport aircraft. My trouble is the material is tan in color and I decided on dark gray for my cockpit color.

Cheers
 
We carry several FAA approved items (and some with no approval) on our web store. While they may or may not survive Dan's flamethrower, I am quite pleased with their reasonably low cost, easy installation, and effectiveness at reducing the heat on my feet (and elsewhere) and reducing sound levels a bit. And they make a very tidy installation if you simply install then run a bead of high temp RTV around the edges. ProSeal works too.

Heat, Sound, Paint and trim

I think I've said it before, I applaud Dan H for making this a talked about topic. It should be given due consideration. Certainly, there are many builders (me included, years ago) who build their dream plane only to find out that they have hot feet, burnt cowlings, and other heat related problems that could have more easily been dealt with during construction.
 
Vince's "Heat Shield Mat", when attached to the engine side of the firewall, looks like a good product to reduce cabin heating under normal operating conditions. It will probably be a plus in the event of an engine compartment fire and certainly won't make it worse.

Comments about hot feet are total nonsense if you cover the engine side of the stainless firewall with an insulator and a reflector. I routinely remove my shoes in cruise flight, stick my feet through the rudder pedals, and rest them against the firewall. This is perfectly comfortable, wearing nothing but socks, in August, and I guarantee my cowl outlet temperatures are higher than 99% of the fleet.

Soundcoat M and Soundcoat CSU are FAR 25.853 materials and a very poor choice for firewall contact. When tested to the FAA firewall standard, similar materials have demonstrated the potential to be Death In A UPS Box.

§ 23.1191 Firewalls.

(f) Compliance with the criteria for fireproof materials or components must be shown as follows:

(1) The flame to which the materials or components are subjected must be 2,000 ±150 °F.

(2) Sheet materials approximately 10 inches square must be subjected to the flame from a suitable burner.

(3) The flame must be large enough to maintain the required test temperature over an area approximately five inches square.

(g) Firewall materials and fittings must resist flame penetration for at least 15 minutes.

§ 23.1182 Nacelle areas behind firewalls.

Components, lines, and fittings, except those subject to the provisions of §23.1351(e), located behind the engine-compartment firewall must be constructed of such materials and located at such distances from the firewall that they will not suffer damage sufficient to endanger the airplane if a portion of the engine side of the firewall is subjected to a flame temperature of not less than 2000 °F for 15 minutes.
 
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hydroguy2 said:
Karl, give me a call. I got a source for a enough Firewall insulation(FAA approved) for 5 planes. Might even get it delivered for free, as I have to bring the roll back to Helena one of these days.

Brian
980-1193cell
Click to expand...
Hey Brian,
Thanks for the offer, I will give you a call, I keep hearing that you are about finished up, I have a ways to go but I would like to run over sometime and check out your project if you have time to show me. I will hold on to your number, mine is 431-5421. Talk to you soon.
Karl
 
My RV-4 and my Rocket were both very effective at feet roasting just from radiant engine heat. It became intolerable during the summer.

Not arguing with Dan, but if you're feet are roasting from radiant heat then the choices are either don't fly or add insulation. Unfortunately, there aren't any perfect insulation systems out there.

For me, I've added both insulation types that I mentioned earlier, carry an aqueous foam fire extinguisher, and usually have a chute on. I'm quite comfortable with my setup. And it's affordable.

I suppose another option might be that some of the industrial safety supply houses carry some very sexy :p foil faced fire boots, but I can't seem to get my head around wearing them to the airport.

"Death in a UPS box" might be a bit extreme and could be applied to virtually every component of an airplane under the right circumstances. You gotta think about and be comfortable with your choices.... and, sadly, they must be affordable since most of us don't have a Boeing budget.

Once again, I applaud Dan H for making this a talked about topic. It should be given due consideration.

YMMV
 
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Could be appropriate

vfrazier said:
"Death in a UPS box"
Click to expand...

Not to speak for Dan, but using the wrong material on the inside of the firewall could easily result in incapacitation due to fumes before the actual fire became a problem.

I bought a 25' roll of ceramic fiber, a 25' roll of stainless foil, and some stainless tape which will do my firewall (on the engine side) and my front floor. Will be mechanically attached. Total cost was less than $300, perhaps somewhat spendy but ................
 
Orcotek, a high quality FAR 25.853 cabin wall insulation. Fiberglass batt with a plastic vapor barrier. Really good stuff to fill the spaces behind wall and door panels. Not so good when placed in contact with a hot firewall.


Oratek.JPG


Soundex Firewall Mat, a black rubber foam with an aluminum foil face, and claimed to meet FAR 25.853. Night photo, so you don't get the see the boiling smoke. How would you like to be trapped in the cabin with this?

Soundex.JPG


A far more suitable material, ordinary high temp ceramic batting, with no sizing or binder. The burner is running on the front side of the stainless firewall panel, exactly like in the previous photos. Well, not exactly like the previous photos....in this case the burner has been running for several minutes. Look close...the stainless sheet is glowing, but my hand is perfectly comfortable. No smoke, no flame. If you insist on placing insulation on the cabin side of your firewall, fold this into plain aluminum foil envelopes to contain airborne fiber, a lung cancer risk. Ordinary HD Reynolds Wrap from the grocery store will work fine. Use a mechanical attachment (no glue please).

Cerablanket.JPG


Far, far better to insulate the engine side and protect the structure as well as your feet. This is 3 minutes into a burner run, an eternity if you have an engine compartment fire. The black heat target (simulating the soles of your shoes) is at 178F. The aluminum firewall angle and rivets are about 300F, meaning they continue to be structurally viable. You may be crying, but you're still flying. No fire extinguisher discharge required. Oh, and you actually had time to turn off the fuel tap.

Engine%20side%20insulation%203%20min.jpg
 
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Seems like there are 2 goals here:

1. Application of the right material to the forward (engine) side of the firewall , and inside surfaces of the cowling) as added protection of the firewall structure, cowling, and cockpit against an engine compartment fire.

2. Application of the right material to the aft side of the firewall & forward inside surfaces of the cockpit surfaces to reduce noise & vibration in the cockpit & provide minimal thermal insulation.

Probably no one product will meet both goals. Careful selection of both is needed because of the aircraft application. In the Navy, we used to say "every person on board ship was a firefighter". Definitely true in a plane as there is no where to go in case of fire.
 
DanH said:
Ordinary high temp ceramic batting.
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Cool Dan - where can one find this batting? Any idea what a square foot weighs? Your measurements certainly prove that it is a great insulator.... do you think it would have any sound reduction properties as well?
 
The biggest problem I can see with the high temp ceramic batting is that WHEN it gets wet, it's gonna stay wet for a long time. Are you prepared to crawl under your dash to remove globs of wet insulation or will you leave it there and hope it doesn't corrode anything important?

For those who haven't experienced a thoroughly soaked RV, please spend a week at Oshkosh. You'll find out exactly where the MULTIPLE water leak points are on your normally hangared RV.

The high temp ceramic batting isn't very good at sound damping, but that's another thread for another day.

As we're seeing with this thread, there is no single perfect solution.
 
kbehrent said:
Which one did you go with?
Click to expand...

I believe it was part number 93315K92.

Just in the middle of making these up and putting them on.

Vince has a good point about the potential of getting this stuff wet. Sandwiched between stainless foil, closed up with stainless tape, and some caulking with Fire Barrier 2000 I believe I will not have a problem with that but.............
 
For the cabin side, ceramic wool batting sealed in folded seam aluminum foil envelopes, with a mechanical attachment method. No glue please. Stainless foil is not necessary on the cabin side. All you need is HD Reynolds Wrap from the grocery store.

For the engine side, ordinary Fiberfrax felt (available Wicks, Spruce, etc) under stainless steel foil, attached with SS pop rivets and sealed around the perimeter with 3M Firebarrier 2000. Common 24" wide SS foil is fine, actually preferred. Overlap a mid-panel seam about 2 inches and cover it with one strip of aluminum foil sticky tape. In a fire the aluminum tape will melt away instantly and provide a directed escape path for the outgassing binder in the Fiberfrax.

The engine-side approach is much superior, but both are free of cabin smoke and insulate well enough to buy a lot of time without burns.

I'm not aware of any safe sound insulator for a firewall. The fire performance of some has been horrifying.

All firewall penetrations should be steel or insulated/protected.

Everyone is welcome to an opinion, but please, first read and understand the standards, then do some actual test work.
 
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DanH said:
Everyone is welcome to an opinion, but please, first read and understand the standards, then do some actual test work.
Click to expand...

Elegantly stated.

Thanks for your concern, and efforts to keep all of us safer while flying.
 
Mike T, do a search for "intumescent"-----we discussed this a while back------set the search for any time, not within the last year.
 
Sound Insulation

Dan, any thoughts about piggybacking sound insulation on the cool side of good firewall heat insulation? Along the same lines, how about putting a bit of thin ceramic insulation under floor pads/carpeting?
 
Thankfully I have no experience with this but about how quickly can you tell if there is an engine fire when cruising along?

I suspect that it is possible to fly without noticing longer than some of the speculation (within a minute or less).

Does anyone have any experience with this sort of thing?


Glenn Wilkinson
 
DanH said:
All firewall penetrations should be steel or insulated/protected.
Click to expand...

Not to hijack the thread but since you brought it up: The 7A plans say to drill a hole for the hinge pins on the side of the cowling to support the part of the cowlings that aren't hinged to the firewall. This would seem to defeat the point of sealing up the firewall (or are people somehow sealing up this hole in a way that makes removing the hinge possible?)

Also regarding "mechanical method of attachment": What are people using to accomplish attaching this material to the firewall. As near as I can tell, it would take several pieces to fit into the various crevices etc.
 
glenn654 said:
Thankfully I have no experience with this but about how quickly can you tell if there is an engine fire when cruising along?

I suspect that it is possible to fly without noticing longer than some of the speculation (within a minute or less).

Does anyone have any experience with this sort of thing?


Glenn Wilkinson
Click to expand...

This has been posted before, but it's worth another look:

http://www.ntsb.gov/ntsb/GenPDF.asp?id=LAX99LA063&rpt=fa

That happened close to me. The pilot was well-known and widely respected in our local homebuilt and acro community. It didn't take long at all for that engine fire to bring him down.

I happen to work with a bunch of pilots; there is still a photo of him next to his plane hanging in our shop. We keep it there in part as a reminder to not be cavalier about those systems that could lead us to a similar demise.

For what it's worth, it was apparently the burning insulation on the cabin side of the firewall that overcame him and caused his mortal injuries.
 
chunt0 said:
Dan, any thoughts about piggybacking sound insulation on the cool side of good firewall heat insulation? Along the same lines, how about putting a bit of thin ceramic insulation under floor pads/carpeting?
Click to expand...

Charlie, it is possible, but the devil is in the details. First you would need a fire insulation system that maintained structure temperatures below the smoke and ignition temperature of the sound insulation at every point it contacts. As a practical matter that is a difficult design task. Here's an example.

5%20min,%20Aluminum%20Angle%20Small.jpg


The burner has been running 5 minutes in this shot. The panel is faced on the "engine" side with an effective insulator and SS foil. The aluminum angle (same size as a Vans firewall) in this test panel is holding at a reasonable temperature. However, see the AN3 nut and bolt to the right of the instrument, just above my thumb? It was installed in the test panel to check heat transmission via a point source. Its temperature is well above the measurement capability of the Raytec. You can't see it in the photo, but that AN3 is glowing a very dim red.....more than hot enough to ignite plastic or rubber sound insulators.

FWIW, my own firewall is bare metal on the cabin side....not even paint, exactly like the test panel you see here.

Complete link for the accident referenced by Lars:
http://www.ntsb.gov/_layouts/ntsb.aviation/brief2.aspx?ev_id=20001211X11589&ntsbno=LAX99LA063&akey=1
 
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Alas, the photos in this thread are no longer available. Anyone (Dan?) able to re-post them an update the thread?

Thanks!

Mike
 
Mike, try again. I was able to see all of the photos today, and on a computer that i have never used before, so they were freshly downloaded.
 
firewall

I bought another piece of stainless steel and made a duplicate of my firewall, put my insulation blanket that was 1/8" thick and rated to 2500 degress and sandwiched the fiberglass between the two pieces of stainless steel and sealed the perimeter. I did this from the engine side. I cut out the insulation/fire Barrier out where the engine mount bolted up so that it would be solid. It worked great and best of all it loooks good.
 
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