Firewall

[Flyhighdave]

I'm building a Barracuda-!/4in. plywood firewall. What is the best material for
the fire barrier? .16 stainless or .16 2024 T-3 with a layer of 1/8in.
fiberfrax sandwiched between the aluminum & the plywood? I'd like to go with
the aluminum because of weight if it & the fiberfrax are an appropriate
combination. Are there any other materials I should be considering?
Thanks!
David

[John]

A gasoline fed fire can reach a temperature of over 2000 degrees.
Aluminum will melt at 1100 degrees. The answer should be obvious.
I would use 0.016 stainless which weighs one tenth of the 0.16.


On 15 Feb 2004 03:51:29 GMT, (Flyhighdave) wrote:

>I'm building a Barracuda-!/4in. plywood firewall. What is the best material for
>the fire barrier? .16 stainless or .16 2024 T-3 with a layer of 1/8in.
>fiberfrax sandwiched between the aluminum & the plywood? I'd like to go with
>the aluminum because of weight if it & the fiberfrax are an appropriate
>combination. Are there any other materials I should be considering?
>Thanks!
>David

[Flyhighdave]

My mistake! I meant to say 0.016 not 0.16. That would be a hefty chunk of
metal!
Tony Bengilis in "Firewall Forward" talks about the 2024-T3/Fiberfrax
combination as being a consideration for a firewall. The fiberfrax is what
provides the fire barrier as it withstands tremendous heat.
Anyway I'm looking to do the best thing, not the cheapest or necessarily the
lightest, although light would be nice.
Any more advice?
Thanks!
David

[Cy Galley]

The aluminum over the fiberfrax is not intended to be a fire barrier. The
fiberfrax is the fire barrier and prevents the plywood behind from even
charring. The aluminum is a mechanical protection to prevent solvent and
mechanical damage to the fire protecting fiberfrax. If you have a fire
severe enough to melt the aluminum, then entire engine compartment will have
to be redone anyway.

--
Cy Galley
Editor, EAA Safety Programs
or


"Flyhighdave" > wrote in message
...
> My mistake! I meant to say 0.016 not 0.16. That would be a hefty chunk of
> metal!
> Tony Bengilis in "Firewall Forward" talks about the 2024-T3/Fiberfrax
> combination as being a consideration for a firewall. The fiberfrax is what
> provides the fire barrier as it withstands tremendous heat.
> Anyway I'm looking to do the best thing, not the cheapest or necessarily
the
> lightest, although light would be nice.
> Any more advice?
> Thanks!
> David

[Richard Riley]

On 15 Feb 2004 03:51:29 GMT, (Flyhighdave) wrote:

:I'm building a Barracuda-!/4in. plywood firewall. What is the best material for
:the fire barrier? .16 stainless or .16 2024 T-3 with a layer of 1/8in.
:fiberfrax sandwiched between the aluminum & the plywood? I'd like to go with
:the aluminum because of weight if it & the fiberfrax are an appropriate
:combination. Are there any other materials I should be considering?
:Thanks!
:David

Best of all worlds - .012 titanium and 1/8 fiberfrax. Hard to find,
but it's out there. Any alloy will do. Ti will burn, but it takes
something like 5000 degrees to light it, and you're not going to get
that in an engine fire. Commercially pure is the easiest to work
with. Try www.tigermetals.net, their prices are good, if they have a
piece big enough for you.

[Del Rawlins]

In > Richard Riley wrote:

> Best of all worlds - .012 titanium and 1/8 fiberfrax. Hard to find,
> but it's out there. Any alloy will do. Ti will burn, but it takes
> something like 5000 degrees to light it, and you're not going to get
> that in an engine fire.

My father in law once set a piece of titanium on fire that he was
machining in a lathe.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

[Tarver Engineering]

"Del Rawlins" > wrote in message
...
> In > Richard Riley wrote:
>
> > Best of all worlds - .012 titanium and 1/8 fiberfrax. Hard to find,
> > but it's out there. Any alloy will do. Ti will burn, but it takes
> > something like 5000 degrees to light it, and you're not going to get
> > that in an engine fire.
>
> My father in law once set a piece of titanium on fire that he was
> machining in a lathe.

An entire B-one A burned to the ground here on the desert.

[David O]

(Flyhighdave) wrote:

>My mistake! I meant to say 0.016 not 0.16. That would be a hefty chunk of
>metal!
>Tony Bengilis in "Firewall Forward" talks about the 2024-T3/Fiberfrax
>combination as being a consideration for a firewall. The fiberfrax is what
>provides the fire barrier as it withstands tremendous heat.
>Anyway I'm looking to do the best thing, not the cheapest or necessarily the
>lightest, although light would be nice.
>Any more advice?
>Thanks!
>David

The original Vari-eze and Long-EZ plans called for a
stainless/asbestos/plywood firewall. In 1980 the Rutan Aircraft
Factory approved an aluminum/Fiberfrax/plywood substitution. The RAF
newsletter said, "Fiberfrax is as good a fire barrier as stainless
steel." Most builders switched to the aluminum/Fiberfrax/plywood
firewall.

As for in-flight fires, the NTSB database (1982 to present) has 46
homebuilt aircraft accidents with an occurrence code of "fire" or
"fire/explosion". Half of those were in-flight fires while most of
the others were fires after impact.

"Highest Injury" breakdown for the in-flight fire accidents:

None: 8
Minor: 2
Serious: 5
Fatal: 8

David O -- http://www.AirplaneZone.com

[Rich S.]

"Del Rawlins" > wrote in message
...
>
> My father in law once set a piece of titanium on fire that he was
> machining in a lathe.

Sure it wasn't Magnesium? Titanium would be a real chore to turn in a
reg'lar lathe, for sure.

Rich S.

[John Ammeter]

On Sun, 15 Feb 2004 12:33:30 -0800, "Rich S."
> wrote:

>"Del Rawlins" > wrote in message
...
>>
>> My father in law once set a piece of titanium on fire that he was
>> machining in a lathe.
>
>Sure it wasn't Magnesium? Titanium would be a real chore to turn in a
>reg'lar lathe, for sure.
>
>Rich S.
>

Oh, it should be easy to turn.... now, if you want to cut
it??

John

[Orval Fairbairn]

In article >,
John Ammeter > wrote:

> On Sun, 15 Feb 2004 12:33:30 -0800, "Rich S."
> > wrote:
>
> >"Del Rawlins" > wrote in message
> ...
> >>
> >> My father in law once set a piece of titanium on fire that he was
> >> machining in a lathe.
> >
> >Sure it wasn't Magnesium? Titanium would be a real chore to turn in a
> >reg'lar lathe, for sure.
> >
> >Rich S.
> >
>
> Oh, it should be easy to turn.... now, if you want to cut
> it??
>
> John

I have used a bandsaw with a smooth blade to friction cut titanium. One
time I had a very small chip catch fire and burn itself out on the
bandsaw table. I think that it takes a lot LESS than 5000 degF to flame
it.

[Del Rawlins]

In > Rich S. wrote:
> "Del Rawlins" > wrote in
> message ...
>>
>> My father in law once set a piece of titanium on fire that he was
>> machining in a lathe.
>
> Sure it wasn't Magnesium? Titanium would be a real chore to turn in a
> reg'lar lathe, for sure.

Yeah, I'm sure. He was working as a millwright in a pulp mill and they
used titanium for a lot of fittings because it had better resistance
than any other metal to the highly corrosive chemicals used in the mill.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

[richard riley]

On Sun, 15 Feb 2004 20:57:48 GMT, Orval Fairbairn
> wrote:

:
:I have used a bandsaw with a smooth blade to friction cut titanium. One
:time I had a very small chip catch fire and burn itself out on the
:bandsaw table. I think that it takes a lot LESS than 5000 degF to flame
:it.

That may be true, but I'm trying to figure out how. Ti melts at
3020°F and boils at 5949°F.

I'm assuming that solid Ti doesn't burn - it's Ti gas that burns, just
like everything else. So, in order to release Ti gas, the solid has
to get to 5900 degrees. Even if it's just a little, tiny point on the
TI that gets that hot.

I've seen white hot Ti sparks coming off a grinding wheel. To be that
color, they've got to be up in the 3000 degree range or hotter.

I've put an old fashioned gasoline blow torch on a thin piece of Ti
and left it there for an hour. It glowed red and got surface
discoloration, but it didn't melt or burn through. The hottest point
in a blowtorch flame is 21-2200 F

BTW, the melting point of 304 stainless is 2590°F. I think if you
have a fire hot enough to ignite Ti, your stainless will be long gone
- along with the rest of the engine compartment.

[Richard Lamb]

richard riley wrote:
>
> On Sun, 15 Feb 2004 20:57:48 GMT, Orval Fairbairn
> > wrote:
>
> :
> :I have used a bandsaw with a smooth blade to friction cut titanium. One
> :time I had a very small chip catch fire and burn itself out on the
> :bandsaw table. I think that it takes a lot LESS than 5000 degF to flame
> :it.
>
> That may be true, but I'm trying to figure out how. Ti melts at
> 3020°F and boils at 5949°F.
>

Well, friction cutting does imply that it is hot enough to melt.
Might a thin chip get enough concentrated heat to double the temp?

[R&R Sherwood]

I saw a Glasair that had an oil fire just after departure. The tower
called him and told him that he was smoking. He made an immediate 180 and
landed the opposite direction. He said that the Fire Dept was hosing him
down as he was still rolling. He said that total flight time was only 2
or 3 minutes.

His firewall was aluminum / fiberfrax / fiberglass covered rohacell. The
aluminum must have melted almost immediately, this allowed the fiberfrax to
move away from the fiberglass covered rohacell. The fire then burned
through fiberglass/rohacell and entered the right side of the cockpit, good
thing he didn't have a passenger. Glasairs have their fuel tank in the
forward section of the wing. The fire now starts burning his into his wing
fuel tank. Only one layer of fiberglass separated the fire from fuel when
the Fire Dept had it put out.

After seeing this I decided to go with stainless. If you have a fire at
altitude you'll sure wish you had not used aluminum. The extra one or two
pounds of a better metal may save your life.

Russell Sherwood
Houston TX



"Flyhighdave" > wrote in message
...
> I'm building a Barracuda-!/4in. plywood firewall. What is the best
material for
> the fire barrier? .16 stainless or .16 2024 T-3 with a layer of 1/8in.
> fiberfrax sandwiched between the aluminum & the plywood? I'd like to go
with
> the aluminum because of weight if it & the fiberfrax are an appropriate
> combination. Are there any other materials I should be considering?
> Thanks!
> David

[James Lloyd]

To whoever is thinking about the wt. of the firewall,You might want to
hear what happened to me a few years ago.I fly an Ercoupe with the
original 5 gal. header tank up front,and whil flying along the shoreline
of Ct. one night,I began smelling what smelled like wood burning.No big
deal I thought because it was summer and I was only at 2000ft.and had
both windows down and I could see people on the beach with fires going
and thought that they were cooking hotdogs and such.It smelled kind of
good to me actually,until I saw the small flames coming from the floor
of the plane.I was alone so I steeped on the flame with my rt. fot to
try to keep it down while I got the fire exh.from the baggage area.As
fate would have it,the small push button on the exh. fell off and onto
the floor somewhere and I could not find it in the dark.I declared an
emerg.at hvn.and headed for it.I was able to keep the fire at bay by
steeping on it every few secs.I got close to the airport and while on
final,I cut the eng. off and glided down.After the fire dept. finished,I
found out that my exh.had broken and the eng. was blowing the hot gasses
directly onto the firewall and that had ignited the wood floorboards
causing the flames.It could have easily blown up the tank but I was
lucky.The exh. only had about 250 hrs.on it since new and I had done a
good preflight.I said all this so that you might make a wiser decision
on your choice of metal and where to put it.Good luck,Jim

[Jerry Wass]

I have a fair quantity of Fiberfrax--1/2" "durablanket"---see ad in
rec.aviation
,marketplace.

James Lloyd wrote:

> To whoever is thinking about the wt. of the firewall,You might want to
> hear what happened to me a few years ago.I fly an Ercoupe with the
> original 5 gal. header tank up front,and whil flying along the shoreline
> of Ct. one night,I began smelling what smelled like wood burning.No big
> deal I thought because it was summer and I was only at 2000ft.and had
> both windows down and I could see people on the beach with fires going
> and thought that they were cooking hotdogs and such.It smelled kind of
> good to me actually,until I saw the small flames coming from the floor
> of the plane.I was alone so I steeped on the flame with my rt. fot to
> try to keep it down while I got the fire exh.from the baggage area.As
> fate would have it,the small push button on the exh. fell off and onto
> the floor somewhere and I could not find it in the dark.I declared an
> emerg.at hvn.and headed for it.I was able to keep the fire at bay by
> steeping on it every few secs.I got close to the airport and while on
> final,I cut the eng. off and glided down.After the fire dept. finished,I
> found out that my exh.had broken and the eng. was blowing the hot gasses
> directly onto the firewall and that had ignited the wood floorboards
> causing the flames.It could have easily blown up the tank but I was
> lucky.The exh. only had about 250 hrs.on it since new and I had done a
> good preflight.I said all this so that you might make a wiser decision
> on your choice of metal and where to put it.Good luck,Jim

[James Lloyd]

Jerry,I think that I bought some from you already,Now you know why I
did.thanks,Jim in Ct.

[Jerry Wass]

Yeah, Thanks Jim, but how else can I tell others who need some ?

James Lloyd wrote:

> Jerry,I think that I bought some from you already,Now you know why I
> did.thanks,Jim in Ct.