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FWF-Insulation glue !

P

Pilottonny

Well Known Member
Yesterday I cut all the various pieces of firewall insulation and ?seemed? them with aluminum tape. It is the kind of insulation, approx 3/16 thick, with an aluminum foil on each side. I tried to get some high-temp glue, but the stuff I was after, is not readily available here in Belgium. So I got some clear ? Poly Max?, a polymer sealer/glue from ?Bison?, from our local DIY.

It said on the cartridge that it would keep its normal strength up to a continuous 100?C (212 ?F). I am not sure how hot the Firewall gets, but I put a sample of the insulation, glued to a piece of stainless steel in the oven, with the following results:

10 min. @ 100 ?C: (212 ?F) No problem!
10 min. @ 125 ?C: (257 ?F) No problem!
10 min. @ 150 ?C: (302 ?F) No problem!
10 min. @ 200 ?C: (392 ?F) No problem!
20 min. @ 200 ?C: (392 ?F) No problem!
10 min. @ 250 ?C: (482 ?F) No problem!

? No problem? means I could not rip the insulation of the stainless steel without damaging it. Also the aluminium tape kept sticking real good! Unfortunately our oven does not get higher than 250?, but I am pretty sure that the Firewall will not get that hot in normal working conditions.

It is good to know that the Insulation will also help to keep the heat out in case of a FWF-fire (and that the insulation will stay on even when it gets quite hot)

Regards, Tonny.
 
<<10 min. @ 250 ?C: (482 ?F) No problem!>>

Tonny, I compliment you for testing before moving ahead. However, the firewall standard is 1093C (2000F).

I've done some experiments with a firewall burn rig. The metal faced insulation you're using is conceptually a good idea. If you can keep it in place, I would expect a heat target 6" behind the firewall (think of your toes) to not get warmer than about 200F with a 2000F firewall, even after 5 minutes or so. Without the barrier the heat target reaches 200F in about 20 seconds.

The barrier won't do you any good if it falls off the firewall....and it will at 2000F if glued. Consider mechanical attachment. I'd suggest aluminum sheet "L" clips pop-riveted to the firewall angles.
 
DanH said:
<<10 min. @ 250 °C: (482 °F) .....The barrier won't do you any good if it falls off the firewall....and it will at 2000F if glued. Consider mechanical attachment. I'd suggest aluminum sheet "L" clips pop-riveted to the firewall angles.
Click to expand...

this way it won't fall off until ~1220*F, when the AL clips fail:D
 
I was under the impression that the oven test was to determine if the insulation would stay put during normal ops, not during an engine fire. I wasn't planning on sticking anything to the firewall in the interest of weight and simplicity, but that 20 second figure has got me googling the web for some asbestos sneakers!
 
Insulation for normal operating temperatures!

Dan,
That is an impressive figure you mention: 200 ?F in 20 seconds! It must be quite a fire, I guess, and very close to the firewall. I will be more worried about the cowling and windshield going up in flames and right in my face, than the 200? F at my toes (same temperature in the sauna).
For sealing the firewall penetrations, etc. I will obviously use the 2000 ?F sealant.

Steve,
Exactly, the idea was to insulate against heat (in the summer) and noise in normal operting conditions. If the insulation sticks on, in case of a fire, even if it is only for an additional 30 seconds, that is still 30 seconds more than with no insulation at all (which most have).
The weight penalty is only 600 gr. (1,3 lb) plus glue. To me that is acceptable for the extra comfort and (minor) safety.

Thanks for your imput, regards, Tonny.
 
Pilottonny said:
I will be more worried about the cowling and windshield going up in flames and right in my face, than the 200? F at my toes (same temperature in the sauna).
Click to expand...

Those Belgians must have some pretty serious saunas! Do they throw a few ears of corn in there with you? :D
 
<<this way it won't fall off until ~1220*F, when the AL clips fail>>

Well, actually, a future burn test with a pseudo-Vans firewall (stainless sheet with aluminum angle ribs) is on the curiosity list. It is entirely possible the aluminum firewall rivets will fail but the angles will survive. The stainless sheet wrinkles up a lot, meaning when the rivets fail there is little or no surface contact between the sheet and the angles to conduct heat. The game becomes a question of how much radiated energy the angles absorb vs how much they re-radiate and/or conduct to air. My bet is that they don't reach melt point because only one face is parallel with the glowing firewall, while two faces are perpendicular and one faces away.

<<It must be quite a fire, I guess, and very close to the firewall.>>

An ordinary propane weed burner will heat an 8" dia area of firewall stainless to glowing red in a few seconds. I calibrate for 2000F with a sheet of copper foil. FAR 23.1191 tests only require a 10"x10" firewall material sample with a 5"x5" hot spot, so yes, an 8" hot spot is a bit larger than the standard.

<<the idea was to insulate against heat (in the summer) and noise in normal operating conditions. >>

Oh, I understand. Still, you might want to try the glue on a section of red hot metal just to see how much smoke and/or flame you get.

In the event of an engine fire, the three issues are smoke in the cockpit (breathing difficulty), how much pain (read radiated heat) the pilot can stand before he loses control, and ignition of flamable materials on the cockpit side of the firewall.
 
Tonny, BTW, what brand of insulation are you using? Foil on both sides, only 3/16" thick, and 1.3 lbs sounds good.
 
Where and how the firewall insulation?

I have thought about firewall insulation and am at the spot where it ought to be done. I was primarily thinking about keeping the cabin cooler during summer operations. Somehow, I thought the insulation was supposed to be on the cabin side of the firewall. But with all stuff being attached to both sides of the firewall, I am not sure where, how thick and how to attach. What have others done?

Regards,

Michael Wynn
RV 8 FWF
San Ramon, CA
 
mlwynn said:
I have thought about firewall insulation and am at the spot where it ought to be done. I was primarily thinking about keeping the cabin cooler during summer operations. Somehow, I thought the insulation was supposed to be on the cabin side of the firewall. But with all stuff being attached to both sides of the firewall, I am not sure where, how thick and how to attach. What have others done?
Click to expand...

I'm going cabin side only. My 6A has none at the moment, but it's considerably noisier than a insulated 9A I've flown. I use ANR headsets which get rid of most of the noise problem; but the noise effects the operation of the intercom.

As far as the engine side, there is a lot of items bolted to the firewall, let alone oil, grease, etc.
I wouldn't dream of putting anything on the engine side.

L.Adamson --- RV6A
 
Firewall Insulation

I bought a yard of 48" wide firewall insulation from Flightline Interiors (see http://www.flightlineinteriors.com/products/construction/default.asp).

I just cut pieces to fit between the firewall reinforcement angles; one yard is more than enough to cover the firewall.

Haven't weighed the insulation yet, but the pieces are very light. I'd guess 1.5-2.5 lbs total for all the pieces.

Next step is to give a scrap or two a burn test and figure out some attachment clips. This thread is very timely; I'll try some "L" clips as suggested by Dan.

Mike
 
Dyna-Mat

I've seen this used in a lot of cars and it is really good. Very thin but dense and absolutely stops any tin-canning. It is relatively low temp (300 degress) but I was thinking of putting it on the firewall side in some of the larger open areas to dampen the vibrations and use the two sided light stuff on the inside with high temp RTV as an adhesive. In a hot fire, fumes would be on the ohter side of the firewall.

http://www.b-quiet.com/ultimate.html

This stuff is made specifically to dampen sound and vibration. Kinda pricey :(

Anyone used it ? I think they actually make a package for the RV10.

Bill S
7a finishing
 
Flightline interiors!

Dan,

It is the insulation from flightline interiors (see mike's post) I tried to set it on fire with a lighter but it did nor burn, just melts, sort of. Good enough for me.

Regards, Tonny
 
Insulation Update

The firewall insulation from Flightline Interiors for my RV8 weighs in at 1lb 6oz...

I can't get it to light (yet...gonna get a hotter flame).

Like Tonny says in his post, the insulation will melt...sort of. I tried lighting it in the center of a sample (on the foil) and nothing happened under direct flame from a lighter. I then tried lighting an edge and the black felt materiel in the center melted in from the foil outer layers about 1/8", and then quit melting. The melted edge appears to insulate the rest of the felt from the flame. No visible smoke and I couldn't smell any fumes. The material also cools quickly. I could touch the foil over the melted area immediately after taking the flame away without getting burned. So far, so good.

I'll try a hotter flame (propane torch) later this week.
Mike
 
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Mike,
Not much point in subjecting the insulation you describe to a direct flame, although it is good to know. It probably passes the tests outlined in FAR 25 Appendix F. For insulating the cabin side of stainless firewall, we just want to know that it doesn't make smoke or ignite when placed very near a glowing metal sheet, and that it doesn't re-radiate enough energy to drive up the temperature of nearby objects (like your feet, plastic brake fluid tubing, etc). We would prefer the above conditions for perhaps 10 minutes. Hopefully an engine compartment fire will starve for fuel by then, or you'll be on the ground. The firewall itself is required to last 15 minutes @2000F on a certified airplane.

My concern in this particular thread is about the glue. Does it smoke or ignite on a red hot firewall? Same is true of paint and other coatings. As for other kinds of insulation, I think folks who insulate the cabin side of a firewall with foam rubber, vinyl-faced, or plastic insulation are, well, in denial.

If you like, send me about one square foot of your insulation and I'll run the burn rig to see what temperature the heat target might reach with extended burn time. If it will keep you toes cool enough to walk away, I call it good stuff.
 
Firewall Insulation Test

Dan,
I'm with you regarding the real test using stainless.

The 'test' I did today was crude, but I wanted to see whether this stuff would burn/smoke/give off fumes before I went too far with it.

Send me a PM with your shipping address and I'll get a chunk in the mail to you for your burn rig.

FWIW, I put my palm on one side of a 6" square piece and applied flame to the other side with a lighter. It got warm, but not hot. Good insulation qualities. Some melting of the 'felt' between the sandwich occurred but the foil seems to dissipate heat well and the foil did not melt. Again, no smoke or apparent fumes.

Mike
 
Ran Mike's insulation on the burn rig tonight. Sample was held in loose contact with the stainless "firewall" using two clamp strips at the vertical edges. Burner is on the other side. Flame was pre-calibrated to 2000F at the stainless using copper foil (melt temp is 2000F). The black square is a radiant heat target six inches from the firewall. The heat target approximates temperature measured at the soles of the pilots shoes.



The sample was emitting heavy black smoke a few seconds after flipping the burner valve. It burst into flame in about 15 seconds. I dropped the Raytec and grabbed the camera. This was about 30 seconds into the test:



A few seconds later, from the "engine" side of the firewall:



The fiberous insulator between the aluminum foil sheets was rapidly consumed. The flames you see here were jetting out from between the foil sheets. The foil was mostly intact after the test, indicating a temperature at the insulation package less than 1100-1200 degrees F.

There is a very large difference between an appropriate firewall insulation and an FAR-compliant cabin wall insulation. This stuff is really, truly awful.
 
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Burn Test

Dan,
Thanks for doing the test.

I just looked at another RV8 project today and the builder was using the same material...I'll pass the results on to him.

So-back to the drawing board!

Mike
 



Dan,
Those are some dissapointing results. Especially since there was no direct flame in contact with it ? Only the immense heat transferred to it from the engine side caused it to burst into flames ?

Confirm please this was the stuff sold by Flightline ?
Seems like it's only good as a mild thermal insulation.

How much of a real engine fire is this simulating ?
What I mean is, how long do you think it would take before the firewall would reach the same conditions as your burn test did ?

Looking at those pictures make one think they'd be better off without anything compared to having that stuff there.
 
Wicked Stick said:
How much of a real engine fire is this simulating ?
What I mean is, how long do you think it would take before the firewall would reach the same conditions as your burn test did ?
Click to expand...

That's my question. I can assume that most of an engine fire is going to be "oil" only, as a fuel. I'll also assume that I'll be smart enough to turn the fuel selector off.

Question is; will engine burn like a blow torch when much of the oil is still in the lower pan? I deal with flames and furnaces daily, as part of my job. But I haven't got around to setting any Lycomings on fire with 100+ mph fans blowing against them. I must really wonder if an engine burning residue oil is going to get a stainless steel firewall hot enough........fast enough? The oil would have to be spraying or atomized to get up to these high temps........IMO.

edit: In fact, until I see definate proof than an "oil only" fed engine fire is going to wrack havoc on the firewall------------I think that some of us are overreacting to the use of certain materials in the cabin.

L.Adamson
 
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I'm not buying the burn test...

After 38 years in the heating business, and seeing vertical and horizontal gas fed flames, day after day...

I just don't believe that a propane fed test stand blowing flames against a stainless steel firewall, is what we're going to see from an oil fed engine fire against an RV firewall. My 100L fuel line will be "off".

Modern oil furnaces work by atomizing the oil into a fine spray. Is the none running aircraft engine going to do this? Will the oncoming airflow
through the cowl inlets atomize most of the oil as it sits engine engine pan? I don't think so!

Nope, I don't buy it. The test is more like using my oxy/ace for silver-soldering refrigeration lines. Those fittings can glow red from the intense heat, and will ignite materials rather easily.

If the engine compartment is really that hot, then I believe the cowl and windscreen will be vaporized too. And I think we'll be toast before the firewall turns cherry red.

One note here: The black rubbery material that covers refrigeration lines was mentioned somewhere in these threads. Might be under the name of Armaflex as well as others. That stuff can actually be right next to the cherry red fittings, and it will just usually start burning on the edge, and can easily be blown out. It really is on the high side temperature proof!

L.Adamson
 
So, if a product can stand up to the propane test, we will have a pretty good safety margin.

I seem to recall that the 2000* test is what the fed/far standard is, anybody confirm this??
 
Yes Mike.

A good place to start is FAR 23.853 "Passenger and Crew Compartment Interiors":

(f) Airplane materials located on the cabin side of the firewall must be self-extinguishing or be located at such a distance from the firewall, or otherwise protected, so that ignition will not occur if the firewall is subjected to a flame temperature of not less than 2,000 degrees F for 15 minutes.

Other good sources are the "Aircraft Materials Fire Test Handbook" or AC-20-135. In addition to the 2000F requirement, you'll find most test specifications suggest a heat transfer rate around 10±1 BTU/ft sq per second.

Want to see what that looks like? This is a photo of a burn test underway at the NAVAIR Aircraft Fire Protection Test Pad Facility, Patuxent River Naval Air Station:



The above burner is the FAA-standard Park DPL. My own little homebuilder burn rig is easily calibrated for 2000F at the firewall surface, but I don't have a calorimeter. Is the propane torch pumping out more BTU's than the Park burner? I kinda doubt it. At 70F, about 35,000 BTU's per hour is the maximum for a 30lb propane cylinder. That works out to be 9.7 BTU per/sec under optimum conditions...total BTU. Not all of it is getting to the steel surface.

I don't know how and why "2000F and 10 BTU/ft sq p/sec" became the standard. I figure the FAA, Navy, etc must have some reason; apparently engine compartment fires do get that hot.

Maybe RVs burn cool <g>
 
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NASA space shuttle tiles?

What material will cope with this kind of heat? Certainly not the cowl and the windscreen. Any suggestions for a firewall insulator, that will?

Regards, Tonny.
 
Pilottonny said:
What material will cope with this kind of heat? Certainly not the cowl and the windscreen. Any suggestions for a firewall insulator, that will?
Click to expand...

I discussed this with my son in law who is a fireman yesterday. If we get the firewall protected to 2000 degrees, then the canopy and cowl will be like a firemans face mask.........gone before the rest of their suit. He also agreed about the oil fed engine, as long as the fuel is shut off.
And, if it's that hot, we're most likely out of it (so to speak) before the interior goes up. The point is to make sure the fuel supply is off, and firewall penetrations are plugged for smoke.

L.Adamson
 
Insulation Glue

I have been reading this thread with some interest because I am at the point where I would like to insulate my firewall. Many years ago, I worked in an industry that did heat treating. Most of the heat treating was done in the 1600 degree F. to 1750 degree F. range. Occasionally, we did treatments in the 2,000 to 2,200 degree F. range. When we took the furnaces to the 2,000 degree range, the maintenance personnel got in a bad mood because the furnace had to be re-built after these high temperature runs. Even the furnace refractory could not stand this temperature indefinately. So far, based on what I have read here, there is no glue and no insulation material that can meet the 2.000 degree requirement and be suitable for airplane use. I pretty much know what NOT to use.
I still have the question of what to use.
Please give me a list of what insulating materials are acceptable and which adhesives are acceptable. If the 2,000 degree test can not be met, then what can I reasonably expect from the best alternate?
Regards,
Chuck
 
Ya'll are missing the point.

The goal is to survive an intense fire for perhaps one minute, or a low intensity fire for maybe 5 minutes. Survival requires no flame in the cockpit, low smoke, and low radiant heat levels. A plain uninsulated firewall will satisfy the first two criteria, but fails big time on the third. When we select an insulation to reduce radiant heat, we want one that doesn't compromise the first two.

Using a burn rig believed to be less intense than the FAA standard, the insulation tested a few posts back burst into flame in less than 15 seconds, while emitting large quantities of black smoke.

The point is to be very cautious about anything you place in proximity to your firewall.....in particular paints, coatings, and glues, and most certainly "firewall insulation" which turns out to be totally unsuitable for a firewall....regardless of how advertised.

Are there insulation materials which will withstand the one to five minute criteria? Yes, of course. The rig in the photos was assembled to check materials intended for my own RV-8. The best candidates so far trend toward a ceramic fiber with a reflective metal backing on the cockpit side (no surprise). I've been spending my time building, and I've not yet had the chance to run comparisons on all the choices. When this thread arose, I offered to test Mike's material because it was on the list anyway. I'll be happy to run other materials if you want to send them.

You think the FAA criteria was set without basis and the results are invalid? Fine. Ignore them.
 
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Good Points Dan

I think your points are very good Dan. I think it would need to go way beyond the firewall, and may not even be possible, to protect to this level. Most of the deadly fires I have heard of where post crash and probably not survivable regardless. I have not heard of any RV in flight fire accidents but there may be some, and nobody wants to be the first for sure.
I do know that my Aeronca would not have complied nor my Bucker. Of course with my Bucker the fire has to burn through my passenger before it gets to me. Ha!
 
I know the original post on this thread was about adhesive, but the thread has "evolved" more than "drifted", IMHO.

Considering Dan H's last comments, I think it is time to revisit this thread
 
Mike S said:
I know the original post on this thread was about adhesive, but the thread has "evolved" more than "drifted", IMHO.
Click to expand...

It no longer matters. I'm going to the airport today, and remove the canopy. I'll install NASA shuttle tiles in the form of an igloo, if Paul D. can set me up with some NASA adhesive that comes in those easy to use cartridges.

The only thing I'm worried about is the periscope which will be along the lines of what Lindberg used. I just don't know if plastic lenses will hold up long enough, or should I go with the more expensive glass ones?

Other than that, I stand by my previous statements; and agree with the recent reply...........that the firewall just isn't enough..

L.Adamson
 
Wrong side of the firewall!

Oh, man,....... that goes on the wrong side of the firewall!

Well,............ I mean the side that is going to be the most difficult to put it on to (with all the stuff that is going to be in the way). Also it is the side that will get: wet, dirty, oily, greasy, etc., etc. :eek:

No, I would rather keep that bare stainless, wipes off a lot easier than that insulated foil backed "stuff".

With the glue, withstanding over 200? C, I thought I had found a good solution for a simple problem, but instead I have a real problem on my hands now! :eek:
I hate it when posts turn out this way ;)

Paul, what about the Space Shuttle tiles, are they expensive? :rolleyes:

Regards, Tonny
 
Thermozite Plus

There were a couple of questions regarding the source of the test sample I sent to Dan Horton for his burn rig so I'll add some data to the discussion:

The sample I provided Dan was a 1'x1' piece of "Thermozite Plus" insulation manufactured by Ozite (http://www.ozite.com/rprod.cfm?item=rp5) and sold by Flightline Interiors as "firewall insulation material."

According to the Ozite website, it is "Made from Eco-fi? (100% post consumer recycled plastic bottles) polyester fiber" with either one (Thermozite) or two foil sides (Thermozite Plus). In other words, a polyester felt sandwich. The website also states "Unlimited applications such as engine hatch covers, hot rods, RV's, door panels/firewalls."

Like many of you, I'm not looking for a heat shield tile solution. As Dan stated above, the 2000 degree test isn't the point.

What I (and I suspect most of us) want is a safe product that can insulate the cabin from engine heat in the summer/help keep cabin heat inside in the winter. One that can insulate without creating a hazard. One that is lightweight and is easy to apply at a reasonable cost.

Oh yeah-I also want it to buy me a few minutes of protection if I should experience a fire.

Thanks again to Dan Horton for providing the heat and putting some of the "E" in experimental. Sometimes experiments show you which path not to take and that's my decision after looking at the photos.

Bottom line for me after Dan's test rig trial: Thermozite Plus is not going on my firewall.

I also spoke with Flightline Interiors this afternoon and recommended that they not market Thermozite as an aircraft firewall insulation solution.

Flightline is a great company with excellent service and I would not hesitate to buy from them again. If you know of an appropriate replacement product, I'm sure they would like to hear from you.

Best regards to all,
Mike
 
Transporter said:
Flightline is a great company with excellent service and I would not hesitate to buy from them again. If you know of an appropriate replacement product, I'm sure they would like to hear from you.
Click to expand...

Now you've got me out in the garage with different materials against a piece of sheet metal and an oxy/ace torch. Two different samples have eventually ignited when the sheetmetal was glowing red. I'll keep trying other materials, but I don't know how hot oxy/ace gets. Couldn't even get a decent answer when googleing for it.

L.Adamson
 
<< One that can insulate without creating a hazard.>>

Exactly. Precisely. The whole point of this thread. Priority one is the same rule practiced by your doctor: Primum non nocere.
 
<<a piece of sheet metal and an oxy/ace torch.>>

Good start Larry.

An OA torch will produce peak flame temperature much hotter than 2000F, as will a propane/air burner or the Park burner. The temperature will vary quite a lot depending on which part of the flame you measure. And when you Google, note the term "adiabatic"...and then ignore adiabatic flame temps.

Temperature is easy. The FAA method has you placing a thermocouple rake where the subject will later be placed, then adjusting either the distance from the torch or the fuel/air quantity to obtain 2000F. The cheapskate method is to hang a sheet of copper shim stock on the fire side of the stainless with some safety wire and adjust the fire until the copper just starts to melt.

No copper shim stock in the shop? Run the burner in the dark and note the color temperature of the steel.

The quantity of heat is more difficult. Remember, we can obtain 2000F in a little tiny spot with a jeweler's torch, or use a great big burner and obtain 2000F across a whole 4x8 sheet. Without a standard, surely some joker would use the jeweler's torch and claim compliance. So, the standard is 10 BTU per square foot per second, which requires a pretty big torch. I've not figured out a cheap and easy way to measure it precisely, mostly because anything close is close enough for our purposes. I'm using my rig for comparisons not certification. Probably pushing less heat into the subject than the FAA requires.
 
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DanH;283231 So said:
the standard is 10 BTU per square foot per second, which requires a pretty big torch. I've not figured out a cheap and easy way to measure it precisely, mostly because anything close is close enough for our purposes.
Click to expand...

Then I've got it......

I'll take 5 furnace burners at 20,000 BTU (per hour) each; derate the total to 83,000 BTU for altitude. Then divide by 3600, which gives me 23.06 BTU's per second That should be good for 2.3 sq. ft. if I don't figure in our gas content which is a bit less than 90%. Might need about 12
burners to simulate a complete firewall..

Now what about the fans to simulate airspeed?
And will they increase heat by adding oxygen, or actually decrease it by cooling? I'll have to throw on a cowl simulate the entrance and exit for air too! It's getting complicated! :)

BTW---- I peeled some of the black insulation of a A/C refrigeration line for the test. At 3500 degrees F. ( or approx.) with the oxy/ace, it caught fire as the torch burned through the sheet metal barrier. It burned for a few seconds and then extinguished itself, but becomes brittle. Someone has already mentioned that this material is sold in sheets. But my HVAC suppliers only have it in tubes to cover refrigeration lines. At 2000 degrees F., it might really be a good solution. It's black and has a rubbery texture.

L.Adamson --- RV6A
 
<<Might need about 12 burners to simulate a complete firewall..>>

Just can't get that "flaming meteor" picture out of your mind, can you?

FAR 23.1191
(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.

That's all you need for a realistic check on the flamability of material placed in contact with a small aircraft firewall....25 sq inches at a nice even 2000F.

Very specific test conditions, including heat flux density, are spelled out in the Aircraft Materials Fire Test Handbook. The handbook is intended for certification of transport category aircraft. As such, the conditions are more severe. Bigger airplanes, bigger fires, more lives at risk. Still, good reading for us, as it offers a realistic picture of how professionals treat the issues.

Discussion about huge fires, melting canopies, and Shuttle tiles is unrealistic, pointless and inflamatory (sorry, couldn't resist the pun). Reality is a 25 sq inch glowing red hot spot on your firewall. The discussion here is about what a builder might place in contact with that hot spot.
 
what about this?

I did a quick internet search, and found the following - http://www.fiberfrax.com/ - made with ceramic fibre.

Anyone have any thoughts or experience with this product? Wicks and Aircraft Spruce sell it, and it appears Berkut uses it for a firewall shield.
Bill Brooks
RV-6A
Ottawa, Canada
 
Glue fails, insulator falls off, back to un-insulated firewall!?

Dan, just a thought: My glue (what this all started with) could withstand 250 ?C. Probably even more than that, lets say 350?C. At that point the glue will fail, or even burn. That will cause the insualtion to fall off the firewall. So we are back to a non-insulated firewall (as most will have) and hopefully no serious harm done yet (other than a bit of smoking glue, in the worst case a bit of burning glue).

The question is: at what temperature will the insulation ignite, before or after the glue fails? Can you do a test, gradually pumping up the heat? (no temperatures down to the third decimal, but accurate up to 50 or 100 ?C)

Anybody found a better insulator yet?

Regards, Tonny.
 
Ceramic blanket

I'm at the insulation stage also.
Planning on using fiberfrax on the lower firewall and about a foot rearwards under the rudder pedals.

This decision was made after seeing the results of an RV-4 in-flight fuel fire. No injuries but the aluminum skin under the rudder pedals was GONE. :eek:
 
Tonny,
<<The question is: at what temperature will the insulation ignite, before or after the glue fails? Can you do a test, gradually pumping up the heat?>>

Yes, I think so. The issue would be accurate temperature measurement, not temperature management. Need a thermocouple and something to read the signal.

Of course you could bypass the whole question with mechanical attachment method.

Bill,
<<This decision was made after seeing the results of an RV-4 in-flight fuel fire. No injuries but the aluminum skin under the rudder pedals was GONE. >>

By chance did you get any pictures? Second or third time I've heard about melting a belly skin just aft of the cowl exit. I installed a stainless exhaust ramp on my -8.

All,
Fiberfrax is on my product list for a test, and I will report results here. Hang loose and I'll order some.
 
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Pilottonny said:
What material will cope with this kind of heat? Certainly not the cowl and the windscreen. Any suggestions for a firewall insulator, that will?

Regards, Tonny.
Click to expand...

Yes. I made a firewall blanket out of foil covered 1/16" Nomex insulation to go on the engine-side of the firewall. The cockpit side has 3/8" thick insulation from AC$, and it looks like its made out of shredded cotton rags coated with fire retardant.

I did an unscientific test with a propane torch, the Nomex insulation just glows on the backside. Looks like it will do the job well. The foil quickly burned off but the flame didn't seem to affect the Nomex.

I got it from Earl's shop over in Gasoline Alley in Indianapolis. They use this same insulation to cover the cockpits of Indy and F1 cars.

http://www.earlsindy.com/linecard.php
 
Ran a sample of a popular foil-backed black foam rubber "firewall insulation" last night. Very strongly not recommended. More later.
 
Dan,
Are you close to running tests on the FiberFrax material? I am also at the point of needing to install firewall insulation. I would like to know soon what materials are good for our needs.

L. Adamson,
any ideas on availability, weight, etc. of the black insulating material you mention for the A/C insulation lines? If there is a source for sheet material for this does anyone know of that source?
 
<<Are you close to running tests on the FiberFrax material?>>

On order at Wicks now. Also some other material they sell, on back order but due shortly, which is why I have not yet gotten to the Fiberfrax.

<<I would like to know soon what materials are good for our needs.>>

Me too, obviously.

<<any ideas on availability, weight, etc. of the black insulating material you mention for the A/C insulation lines? If there is a source for sheet material for this does anyone know of that source?>>

I didn't mention it. I don't recommend it, at least not in direct contact with a firewall, because I suspect it is what I checked last night. As always, happy to test any specific material you want to send.
 
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