What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Firewall sealant and Fire Safety

Jimzim

Well Known Member
Can anyone recommend a source for a firewall sealant that can easily be mixed/dispensed in small quantities? Each time I need a dab, I can use Pro Seal but the shelf life is short and I can't find a small quantity at a reasonable price. What else might be out there? The high temp RTV is only rated to 600 degrees F.

Thanks in advance! Jim
 
Keep your ProSeal in the fridge .... you do have a beer fridge in the shop, don't you? It will last for years. No worries using it for jobs like this.

Vince
 
Firewall sealant...

Pro Seal (for fuel tanks) is NOT a good firewall sealant! I don't know what temp it's good for, but it's nowhere near 600F, and it burns.
Vans sells a firewall sealant, but it's not cheap and has to be mixed as well (maybe that's the stuff you are talking about). I used it to seal my firewall and all the openings I could at that time. The rest got the Hi-Temp RTV.
 
Which one?

Thanks,
Dave

The 3M product that Dan cited is what I bought at Home Depot - expensive tube, but if it lives up to its claims, it should be well worth it! I used it for the firewall recess on the -3, and will be using it for the rest of the -3 firewall sealing job as well. Much better high temp properties than Red RTV, FAR better than pro-seal.

Paul
 
Picking it up locally would be a big plus, since most of the products you'd want are going to be hazmat and incur a big shipping upcharge.
 
Let's be careful here guys. Best I know Home Depot sells 3M "IC 15WB+ Fire Barrier" and 3M "CP 25WB+ Fire Barrier" caulks. These are latex products, not silicone, and are only rated for max service temperature of 180F. They are also far less durable. For example, the silicone sealant has three times the tensile strength and a rated elongation of 500%, both good things for a dynamic application like an airframe.

Spruce has Fire Barrier 2000+.
 
Question for DanH

Any opinions about the relative performance of Flamemaster CS-1900 vs. 3M Fire Barrier 2000+? I didn't know if you had ever tested the CS-1900.
 
Thanks

I've got a tube of 3M Fire Barrier 2000+ in the shop and a couple of SEM tubes of CS-1900 on the way from Sky Geek. Need to get the firewall sealed no later than Saturday and I'm trying to decide if it's worth waiting for the CS-1900 to show up.
 
I've got a tube of 3M Fire Barrier 2000+ in the shop and a couple of SEM tubes of CS-1900 on the way from Sky Geek. Need to get the firewall sealed no later than Saturday and I'm trying to decide if it's worth waiting for the CS-1900 to show up.

Ooooo, an opportunity for direct comparison. Won't help your schedule, but I'd burn check CS1900 if you want to send some.

The only downside I noticed with FireBarrier 2000+ was a tendency to lose its surface adhesion to red hot stainless. On the "cabin" side it remained perfectly intact but peeled and fell off the glowing vertical surface. The lesson is to use it where there is some mechanical grip assistance to help it stay in place....corners, edges, holes, inside passages, etc.

Under direct flame it slowly ablated to powder char, which I assume to be mostly the calcium carbonate component. Thin sections should probably have a metallic shield over the sealant if sealant failure would allow flame penetration. With a shield FireBarrier 2000 would be pretty bulletproof.

It would be interesting to see how well CS1900 resists peel and char.
 
Last edited:
Testing

Well . . . . . I ordered 4 tubes of CS-1900 and I doubt if I would use all four of them anyway. PM me your mailing address and I'll send you one as soon as I get them in.

(edit: FedEx now says Monday the 16th)
 
Last edited:
Is High-Temp RTV suitable? Or does it dry out and crack? How about fuel tank sealant covered (protected) with aluminum tape? Might that be suitable?
 
3M sealant

I am close to sealing my firewall and saw this post so I didn't even need to do a search. Thanks for the info Dan. I purchased (1) case (12) 10.3 oz. tubes on E-Bay for $67.00 delivered. Part # 98-0400-5299-9 3M Fire Barrier 2000+ ( use by date 3/10/12 ). If I can help someone out I will ship out a few tubes. I can't believe I will need more than 1 to 3 tubes at best. Thanks Ron RV- 8a 815-291-8864
 
I've used both CS-1900 and Fire Barrier 2000+ (but haven't burn-tested either product).

The OP asked about a material suitable for small dabs. That wouldn't be CS-1900. Once you mix it in the SEM cartridge you can slow the reaction by freezing it, but you won't stop it. I used the CS-1900 to seal the firewall recess and some spots around the lower edges of the firewall where it intersects the skin. I put the leftover back in the freezer. When I checked it a week later it was useless. Besides that, it's curious material. It's a polysulfide, but unlike regular "proseal", it's barely sticky at all. To the point that I wondered if it would stay put when cured. It does though; once it kicks it adheres well.

Fire Barrier 2000+ on the other hand is a type of silicone sealer. Like any silicone it'll last for quite a while as long as it's not exposed to the atmosphere. Since the cartridge I got had a nozzle with no cap, I just put a piece of clear packing tape over the tip when I'm done. This stuff is sticky, like any silicone. And like any silicone, at least when I handle it, the stuff defies gravity and gets all over me. Occupational hazard.

Also: Fire Barrier 2000+ is intuminescent; it swells mightily when it gets hot. The stuff is really meant to go inside crevices or (for example) a tubular firewall penetration. There, it'll swell up and seal in the face of heat or fire. Dan's previous testing showed that it doesn't adhere well at all to an exposed surface. Using it as a fillet sealant will keep out fumes under normal circumstances, not sure how effective it would be in a fire.

I know nothing about CS-1900's behavior under the same circumstances. My application of CS-1900 was both as a fay sealant and as a fat fillet at firewall gaps in the corners. Dan, it would be interesting to learn the result of any test you do. I've been suspicious of those fillets ever since I applied them, though under normal conditions the stuff is staying put.
 
CS 1900 in a can... mix it yourself as needed

CS 1900 can be purchased as a two part mix in a can... easy to make a small batch as needed and pretty economical.

can be hard to find a source so here is a link http://www.sealpakcoinc.com/

img1927txd.jpg
 
Last edited:
3M

I talked to 3M about their products. The 2000+ is good to 300F. It is meant for fireplaces and not for commercial construction. Under heat, it turns black. It can be replaced by scraping it off and adding more. May or may not be appropriate - 3M support was not comfortable with its use in our environment.
 
Lars, I earlier assumed Fire Barrier 2000+ to be intumescent but after studying the MSDS sheet I'm not so sure. Didn't think about it at the time, but my photo record of burn sessions doesn't show much (if any) swelling typical of intumescent products. And, the MSDS doesn't list vermiculite, just calcium carbonate. There are ways to make calcium carbonate products intumescent, so I dunno. I'll look more closely at that particular aspect when I heat some along with the CS1900.

FWIW the 3M latex fire caulks do list vermiculite.

The primary advantage of an intumescent product is the ability to swell and seal a hole left behind when something else burns away or melts. A good example would be a plastic pipe passing through a concrete wall in a building. The fire melts the pipe but the hole is immediately sealed. In the airplane app we have push-pull cables and wires passing through the firewall, but they are mostly steel or copper and won't entirely burn away in any case. So do we really need an intumescent?
 
CS 1900 can be purchased as a two part mix in a can... easy to make a small batch as needed and pretty economical.

can be hard to find a source so here is a link http://www.sealpakcoinc.com/

More good info. When I got mine, the only way I could find it was in SEM tubes. In fact I got it from Van's. They had it in stock but would not ship. I had business in Portland, so I stopped by & bought two tubes. Then brought it home by (ahem...) other means. It does stink to high heaven. It's been some time since I looked at the MSDS, but I remember that the contents made it obvious why it had become a hazmat substance.

I talked to 3M about their products. The 2000+ is good to 300F. It is meant for fireplaces and not for commercial construction. Under heat, it turns black. It can be replaced by scraping it off and adding more. May or may not be appropriate - 3M support was not comfortable with its use in our environment.

Maybe it's my cynical side, but I'm not surprised that 3M would be uncomfortable, though maybe I'm reading their response wrong. Interesting that's it's only good to 300?F. My recollection was that it was dependent on whether or not it was exposed to direct flame. Thanks for calling 3M. I'm as guilty as anyone of discussing technical data with everyone except those who are likely best-qualified to have the answers.

Lars, I earlier assumed Fire Barrier 2000+ to be intumescent but after studying the MSDS sheet I'm not so sure. Didn't think about it at the time, but my photo record of burn sessions doesn't show much (if any) swelling typical of intumescent products. And, the MSDS doesn't list vermiculite, just calcium carbonate. There are ways to make calcium carbonate products intumescent, so I dunno. I'll look more closely at that particular aspect when I heat some along with the CS1900.

FWIW the 3M latex fire caulks do list vermiculite.

The primary advantage of an intumescent product is the ability to swell and seal a hole left behind when something else burns away or melts. A good example would be a plastic pipe passing through a concrete wall in a building. The fire melts the pipe but the hole is immediately sealed. In the airplane app we have push-pull cables and wires passing through the firewall, but they are mostly steel or copper and won't entirely burn away in any case. So do we really need an intumescent?

Thanks, Dan. So far I've used the 2000+ on small stuff. I still have an unused tube of CS-1900 in the freezer at my hangar (you do have a mini fridge in your hangar, don't you?) awaiting installation of the top forward skin. The SEM cartridge contains lots more than I'll need, so I have the option of using the excess to seal the metal penetrations I have for electrical conductors (took the easy way out and used Safeair1 kits).
 
I talked to 3M about their products. The 2000+ is good to 300F. It is meant for fireplaces and not for commercial construction. Under heat, it turns black. It can be replaced by scraping it off and adding more. May or may not be appropriate - 3M support was not comfortable with its use in our environment.

302F is a max service temperature, the long term static environment, not the firestop condition. The ASTM E814 firestop test subjects the sample (a combination of products in a specific construction) to radiant temperatures of 1500-2000F using a 5ft x 5ft furnace containing a 1.5 million BTU burner.

Another illustration; I previously mentioned the 3M latex fire caulks have a max service temperature of only 180F. They incorporate vermiculite, the classic intumescent firestop material, which doesn't even begin to expand until about 600F.

While you're thinking about it, consider the standard silicone firesleeve on your hoses. The CS1900 may be better...we'll see.
 
Last edited:
Cotronics Resbond 907GF

Many years ago I used Cotronics Resbond 907GF in a OEM application and recently tested it for sealing firewall penetrations and holes.

The product exhibits very good bonding qualities and adheres well to stainless steel.

I tested the product by simulating firewall small hole plugging and bonding by "gluing" two pieces of stainless steel together. After curing overnight I was able to break the bond by prying with a screwdriver but was impressed with the strength as I did no prep to SS.
I exposed the cured product to a torch and heated the SS/ Resbond to red hot condition, I observed no smoke or odor and after cooling the bond was just as strong.

Based on my previous OEM use and recent testing, I believe this product to be ideal for firewall use.

Data sheet link:
http://www.cotronics.com/vo/cotr/pdf/907gf.pdf
 
If the HD stuff stocked at your local store really is inadequate, you might try a well stocked electrical supply house that serves commercial/industrial electricians. A lot of commercial building codes, like automotive regs, can make aviation requirements look wimpy.

I think the buzz word to look for is:
http://en.wikipedia.org/wiki/Intumescent

Charlie
 
Here is what we use at work:
http://www.nelsonfirestop.com/
Now in our application, which is a US Coast Guard certified Ferry Boat, the Nelson Transit (mct) is what cables use to penetrate a fire boundary bulkhead.
Red rubber type blocks fill around the wires, in a flange collar welded into the bulkhead. Mineral wool and the red RTV like product are used on older transits.
This company specializes in the application refered to in this post, but mostly buildings and ships.
I think th CLK silicon caulk, and the Puttybar might be applicable to us?
I hope Dan H or someone who is good with MSDS and Tech sheets might find something here?
For myself; I have a RV-8 QB fuse, and have done nothing yet about 'structural fire protection'.
I have an experimental engine, so I know this is important.
Ground running is one thing; I can shut down, jump out and grab the garden hose or fire extinguisher, but now I have an N number and I've fitted the wings, so...I need to get serious about the risks involved.
 
Last edited:
A variety of popular sealants have arrived here, with one more on the way. I will give them **** (literally) and report, hopefully in a week or so.
 
Order from them:
https://www.cotronics.com/vo/cotr/order.htm

I wonder about the small tube fo 907. Seems to be very high temp too and smaller, maybe cheaper...?

2300°F Resbond™ 907GF Adhesive & Sealant
This moist, creamy putty is easily applied from standard caulking cartridges for use from -300°F to 2300°F.

Just apply to steel, stainless, iron, most metals, ceramics, ceramic cloth, tapes, gaskets, tadpole gaskets, etc.

907GF air dries in 4-12 hours at room temp. (curing may be accelerated with mild heat) and is resistant to most chemicals, solvents, oxidizing and reducing atmospheres, aging, thermal cycling and electricity.

Use for bonding, sealing and repairing exhaust systems, fire brick, gas turbines, brazing fixtures, equipment, stacks, etc. Ideal for use in any high temperature Assembly, Production, Repair or Maintenance Application.
 
Last edited:
Resbond 907

I sent a sample of the Resbond 907GF Adhesive & Sealant to Dan Horton so I suggest holding off purchase. I believe it will perform well in this application but Dan's testing will confirm.
 
A variety of popular sealants have arrived here, with one more on the way. I will give them **** (literally) and report, hopefully in a week or so.

Hi Dan, will you be testing RED RTV 736 ?
This is what my friend at Boeing said they still use. I just had a read on the back of the tube and it said "When heated to temps above 150C (300F) can form formaldehyde vapor" This is a potential cancer hazard.

What can I expect the temps to get up to under my cowl in normal flight ?

Thanks
 
Hi Dan, will you be testing RED RTV 736 ?

I wasn't planning on that particular product (Dow Corning, yes?), but I do intend to stop by the local auto parts store and pick up a tube of "Permatex Ultra Copper". It seems to be the common-as-dirt choice for a high temp silicone sealant here in the States.

What can I expect the temps to get up to under my cowl in normal flight ?

We're not yet into the really hot time of year here in Alabama, but I've been seeing inflight air temperatures around 250F exiting the bottom of a cylinder head and around 160F exiting the oil cooler. I've not measured temps after shutdown, but I'd bet money on 200-250F. Obviously radiant heating could go higher in proximity to an exhaust pipe.
 
Last edited:
EDIT July 2022: I'll have complete firewall insulation kits available shortly. They will include an intumescent mat insulation superior to Fiberfrax 970 felt, with a choice of 0.060" or 0100" thickness, and a 0.002" or 0.005" stainless foil cover sheet. Both are pre-marked for a precise fit, using patterns developed from factory firewalls. You'll also get appropriate SS rivets with large heads, a tube of 3M Firebarrier 2000+, aluminum tape for the center overlap, and depending on model, formed stainless steel or aluminum trim parts. CONUS shipping is free, and every kit includes detailed installation instructions. The kits will cover RV-6/6A, RV-7/7A, RV-8/8A, RV9/9A, RV-10, RV-14/14A, and the RV-15 when I can get a factory firewall for pattern development. Expect a formal announcement here on VAF in due course.

Ok, here we go. Sorry to take so long. Had to assemble a new fire rig as the old one was long ago dismantled and recycled, and I decided to allow plenty of cure time for the test materials.

First, the candidates:

Products.jpg


Cotronics Resbond 907GF (courtesy of Don Pansier)
Rectorseal Biotherm 100 (courtesy Dan Langhout)
Flamemaster CS1900 (courtesy Dan Langhout)
3M FireBarrier 2000
Permatex Ultra Copper

Practical notes, not fire related:

All are single-component except for CS1900, which requires mixing.

Resbond doesn't tool very well. The three silicones (Biotherm, FireBarrier, Ultra Copper) tool, well, like silicones; FireBarrier and Ultra Copper do best in this group. CS1900 is nothing like proseal and doesn't really tool at all. It is more like a blob of uncured rubber or playdough.

The silicones stick well, the Resbond a little less so, and the CS1900 is not very adhesive.

When cured, Resbond is hard. The silicones are what you would expect. The CS1900 feels like soft tire rubber.

The setup:

Setup%20Front.jpg


18 x 24 sheet of stainless firewall material. At the top are simple strips of sealant on the front and back of the panel (staggered). At the bottom we have actual firewall electrical penetrations, very basic; 6-gauge tefzel wire through plastic snap bushings, then covered with sealant, without SS shields. I selected this sort of pass-through because they are commonly seen on experimental aircraft. On the left is a personal experiment, the pass-through style on my own airplane, a 2"x2" .032 plate with a 1.5" long .035 tube, welded 4130. The cable, wires, or whatever is inserted, then the tube is pumped full of sealant.

Here's the back of the panel. I made a point of equally filling each snap bushing with sealant

Setup%20back.jpg
 
Last edited:
Bring on the heat.

Bring%20on%20the%20heat.jpg


First the burn rig was calibrated to approx 2000F using copper sheet. Note that (compared to previous firewall tests) I have reworked the torch nozzle to obtain a tighter, more horizontal hot spot pattern. Also note that none of the sealant samples here are actually in the 2000F hot spot.

Let's go closer:

30%20Seconds.jpg


Approx 30 seconds into the burn. The CS1900 has burst into flame. All three silicones are also outgassing flammable material, but not like the CS. The Ultra Copper sample is the worst of the silicones in this regard. The burn exhibited by these four samples is not entirely a bad thing, as the probable operating scheme is to form an insulating char. The Resbond appears to be inert. Compare the silicones to the previous setup photo and you'll see the Biotherm and FireBarrier samples are exhibiting some degree of intumescence, swelling and expanding. Now look at the 6-gauge wires; so far all the sealant samples are holding up ok (even if outgassing flammable material), but the wire insulation is burning away. I point this out because sometimes I bump into a builder who assumes Tefzel insulation to be fireproof.....it ain't so.

Back of the panel at about 45 seconds:

45%20Seconds.jpg


Hmmm...the Ultra Copper strip sample has burst into flame. The Biotherm sample had flamed slightly and then fallen away leaving some adhered residue. The CS1900 has peeled and fallen away cleanly, not even leaving a mark. Resbond and FireBarrier are doing fine.

Looking at the steel pass-through, we see intumescent FireBarrier squeezing out of the gaps in the joint. Same is true at the plastic bushing (center). So far all the plastic bushings are holding up ok, which means all the sealants are doing a decent job of slowing heat transfer; in thick sections they are serving as insulators.

Front of the panel at about 1 minute:

1%20minute.jpg


All the pass-through samples have remained intact and formed an insulating char. Of the strip samples, only the CS1900, FireBarrier, and Resbond remain adhered. The difference is mechanical; the 6-gauge wire is keeping the sample in place over each of the bushings. There's a lesson here; give your sealant a mechanical advantage!

Back of the panel at about 1-1/2 minutes:

1%20and%20Half%20Minutes.jpg


The snap bushings are now melting. The copper wire cores are very hot, so the tefzel insulation is beginning to soften and swell. All the strip samples have peeled away, except for the Resbond.

More later.
 
Last edited:
Envalope Please......

Augh! Don?t make me think, it looks like there are pros and cons, to several firewall sealants. Dan, what would you use, with what you know now, to seal a firewall?
 
Full failure at less than 2 minutes; the bushings melt, leave a gap, and hot gas is free to do its thing. The CS1900 and Resbond plugs remain pretty much intact and block most of the opening, while the wire stubs collapse the soft silicone chars and fall out of the holes.

I've moved the torch to aim directly at the welded steel pass through; note the new location of the glowing hot spot. The intumescent FireBarrier is squeezing out everywhere. The fitting remains gas tight despite the heat.

2%20Minutes.jpg


Front side again. The CS1900, FireBarrier, and Resbond strips are still hanging. The torch is aimed directly at the welded tube fitting, which is glowing red. In another minute or two the red hot copper wire core will ignite the tefzel insulation on the opposite side, at which point I ended the burn.

2%20Minutes%20Front.jpg


Hot-side chars collected post-burn. They are soft and fragile, puffballs really:

Puffballs.jpg


Note the CS1900 char still intact on the wire. It was tougher than the silicone chars. Also note the Resbond strips. Although entirely intact, they released from the stainless with no effort.

Chars.jpg


Conclusions are subjective, and my opinion...

CS1900 looks like an excellent sealant for use between fay surfaces and in thick sections with mechanical fixation. Good resistance to direct flame but with a lot of smoke and burning, so I'd be very careful about allowing any more than a trace to show on the cabin side of a firewall. Adhesion is poor. Mixing is a PITA.

Resbond can be called fireproof for our purposes, or close to it. I noticed no smoke or outgassing. The catch is its hardness; it has little flexibility when cured and none after heating, when it become about like a charcoal briquette. I did a separate test by applying a sample to stainless sheet. After cure I bowed the stainless 20 degrees and the Resbond strip popped off intact; it doesn't bend. Although the hands-down champ for fire resistance if used in the absence of flex or vibration, I doubt it will stay sealed in a highly dynamic application. Still, very interesting material, and possibly the big winner for sealing firewall overlap seams.

FireBarrier is easily the best of the silicones. It has excellent cold adhesion and about the same hot adhesion as Resbond. Obviously flexibility and dynamic sealing is good. The char is not as tough as CS1900 char and may blow away in high velocity air, and for the same reason is not as resistant to direct flame exposure. It is highly intumescent, expanding to fill voids as other components burn away.

Biotherm had poor hot adhesion. Ultra Copper also had poor hot adhesion and was surprisingly flammable. I'd pass on both.

None are "best". Each has particular properties which need to be carefully considered for a particular application. Sorry, building airplanes requires some thought.

Me? I used FireBarrier silicone in two ways.

Cables and wires got tubular steel fittings like the one in this test. In the real world FireBarrier is intended for fire sealing cable and pipe passages through walls and ceilings. The surface char insulates the remaining sealant, which is well supported inside the passageway. If the pipe or wire burns away the intumescent property seals the void. No surprise that the same principles work in this airplane adaptation.

The firewall perimeter got a filet of FireBarrier before adding the foil/insulator sandwich, the edges of which were sealed with another filet.

Firewall%20Penetrations.jpg
 
Last edited:
THANK YOU DAN!

I agree with Jamie, Outstanding! Truly, you may never know, but you could have very well saved someone?s life though your efforts. I?ve seen on other threads, where people have responded, ?ya, ya, but I think I?ll just use bubble gum, because I don?t plan on having an engine fire.? It?s truly a chilling idea, that that could be their last thought.
Thank you again, for your efforts, and insight!
 
Many Thanks!

Thanks Dan for your efforts! One useful outcome for me is that as good as CS-1900 seems to be, it doesn't appear that it has any particular advantage over Firebarrier 2000+ for standard firewall sealing uses (e.g. sealing the joints between the skin and firewall flange or other fay sealing situations).

<snip>
Me? I used FireBarrier silicone in two ways.

Cables and wires got tubular steel fittings like the one in this test. In the real world FireBarrier is intended for fire sealing cable and pipe passages through walls and ceilings. The surface char insulates the remaining sealant, which is well supported inside the passageway. If the pipe or wire burns away the intumescent property seals the void. No surprise that the same principles work in this airplane adaptation.
</snip>

I am taking this approach as well (tubular fittings) but was intending to use clamped firesleeve inside and outside the tube due to maintenance/serviceability issues. (I did make my own tubes - thanks Dan!) Just filling the tube with sealant is much simpler and obviously works fine. I would just be concerned with the difficulty of, say, replacing a control cable and trying to dig all that sealant out of the tube later. Any thoughts?
 
....as good as CS-1900 seems to be, it doesn't appear that it has any particular advantage over Firebarrier 2000+ for standard firewall sealing uses (e.g. sealing the joints between the skin and firewall flange or other fay sealing situations).

The CS1900 is more resistant to direct flame and has a tougher char, but neither matters much in a fay seal. On the flip side, I was surprised to see how much flame and smoke it generated in the course of forming that char.

I am taking this approach as well (tubular fittings) but was intending to use clamped firesleeve inside and outside the tube due to maintenance/serviceability issues.....Just filling the tube with sealant is much simpler and obviously works fine. I would just be concerned with the difficulty of, say, replacing a control cable and trying to dig all that sealant out of the tube later. Any thoughts?

Yeah, the "pump it full" method is fast and easy to install, but I'd hate to try adding a few new wires to a bundle. Not so worried about engine control cables. I'd be replacing them for a reason so I wouldn't care about trashing them during removal.

Perhaps a mix of the two methods? In the building construction firestop application, the core of the pass-through is often packed with a fiber insulator around the pipes or wires, then the sealant is applied in a layer over the fiber, sort of like a rubber stopper in each end of a packed tube.

All design is a matter of carefully considered compromise.
 
Last edited:
Dan for President

Dan, I will echo the sentiment others have already put out there.

Your efforts are a real asset to the entire VAF community, and there is a good chance you may save someone from a future injury, or death.

The photos of various products failing miserably are pretty convincing to this old fireman.

I will be removing my firewall insulation before my next flight, based on your testing.

I think the information in this thread is of such value, I am going to make it a "sticky" for easier finding in the future. And added "fire safety" to the title.

Again, thanks for all your efforts, and for sharing them with us.
 
Last edited:
DanH, is it possible to use the 3M firebarrier multiple times? How are you storing it for reuse (if so)

It's like any other RTV silicone...seal it from the atmosphere. I tape up the cut nozzle with aluminum foil duct tape.
 
Another test requested

Ok, here we go. Sorry to take so long. Had to assemble a new fire rig as the old one was long ago dismantled and recycled, and I decided to allow plenty of cure time for the test materials.

First, the candidates:

21jwxoy.jpg


Cotronics Resbond 907GF (courtesy of Don Pansier)
Rectorseal Biotherm 100 (courtesy Dan Langhout)
Flamemaster CS1900 (courtesy Dan Langhout)
3M FireBarrier 2000
Permatex Ultra Copper

snipped

Dan,
Sorry, but I'm very late coming to this thread. Thanks to everyone, especially Dan, for all the comments & ideas. I believe, however, that I have one consideration that no one has mentioned yet. How will these products hold up in the presence of aviation fuel and oil??? A great product which dissolves in gasoline or oil is next to worthless it would seem to me.
I ask, because silicone based products like the Permatex Ultra Copper are dissolved by gasoline. As an auto mechanic, I used to regularly use gasoline as a solvent to clean RTV silicone from auto parts. I'm sure many of you will recall the disastrous results pilots have had when they used RTV on carburetor parts. [ A number of forced landing caused by RTV ending up jamming float needles are listed in the archives of this forum]
Since the 3M Fire Barrier 2000 is silicone based, I wonder how it would hold up on the front side of the firewall, where it will be exposed to fuel and oil??
I note that the CS 1900 is listed as "fluid resistant". I believe that this is the sort of consideration that takes place when one designs a product for a specific environment [like an aircraft's FWF]
Perhaps it would be wise to cure these products and submerge them in 100LL and 93 octane auto fuel for a few days to see what happens to them. Obviously, the 3M product is only partly silicone, so perhaps it will hold up? Or maybe the other components in it will fair even worse when combined with fuel?
For those of you who already have Fire Barrier 2000 installed, it may be best to take care when fuel is spilled onto the firewall to clean it off immediately. My experience with fuel and silicone products is that exposure for a short period is not a big problem. Continued contact IS an issue. How about a solvent test Dan??
Perspiring minds want to know! :)
Charlie Kuss
 
Back
Top