4130 can't be OA welded?

"Richard Riley" wrote in message ...
On Fri, 28 Dec 2007 19:46:57 -0800 (PST), "
wrote:

On Dec 28, 2:57 pm, wright1902glider wrote:
the author
seems to think that 4130 cro-mo steel can't be welded with an oxy-
acetylene torch.
--------------------------------------------------------------------------------

Pure bull****. Indeed, for the stresses encountered in bicycles
(which is what he's talking about) there are any number of BRAZING
compounds that yield joints stronger than than normalized 4130.

O/A does just fine airframes... and for bike frames.

If brazing gives stronger joints that normalized 4130, why aren't we
brazing airframes?

(I'm not saying it's an incorrect statement - I know better than to
disagree with VD on something like this. I just figure there must be
a reason, like the brazing compounds are more expensive.)


Won't withstand high temperatures?

Blueskies wrote:
"Richard Riley" wrote in message ...

On Fri, 28 Dec 2007 19:46:57 -0800 (PST), "
wrote:


On Dec 28, 2:57 pm, wright1902glider wrote:

the author
seems to think that 4130 cro-mo steel can't be welded with an oxy-
acetylene torch.

--------------------------------------------------------------------------------

Pure bull****. Indeed, for the stresses encountered in bicycles
(which is what he's talking about) there are any number of BRAZING
compounds that yield joints stronger than than normalized 4130.

O/A does just fine airframes... and for bike frames.

If brazing gives stronger joints that normalized 4130, why aren't we
brazing airframes?

(I'm not saying it's an incorrect statement - I know better than to
disagree with VD on something like this. I just figure there must be
a reason, like the brazing compounds are more expensive.)



Won't withstand high temperatures?



Structural brazing works just fine - if done correctly.

But too much heat causes the brass to migrate into the grain
of the 4130 - resulting in cracks.

It HAS to be done right.
And there is no way to tell afterwards if it was or not -
until it breaks.


Richard

"cavelamb himself" wrote in message ...

Structural brazing works just fine - if done correctly.

But too much heat causes the brass to migrate into the grain
of the 4130 - resulting in cracks.

It HAS to be done right.
And there is no way to tell afterwards if it was or not -
until it breaks.


Richard

I meant while the part was in service. If an engine mount was brazed, and there was an engine fire, would the braze
joint fail (come apart) where a welded one would hold?

Blueskies wrote:
"cavelamb himself" wrote in message ...


Structural brazing works just fine - if done correctly.

But too much heat causes the brass to migrate into the grain
of the 4130 - resulting in cracks.

It HAS to be done right.
And there is no way to tell afterwards if it was or not -
until it breaks.


Richard


I meant while the part was in service. If an engine mount was brazed, and there was an engine fire, would the braze
joint fail (come apart) where a welded one would hold?




Dunno, Mongo.

I guess it would depend on how hot for how long.

But remember that it takes an acetylene flame to braze in the first
place.

If if gets that hot in the engine room, whether the mount welds hold or
not is probably going to be a secondary issue...

Richard

I meant while the part was in service. If an engine mount was brazed, and there was an engine fire, would the braze
joint fail (come apart) where a welded one would hold?




Dunno, Mongo.

I guess it would depend on how hot for how long.

But remember that it takes an acetylene flame to braze in the first
place.

If if gets that hot in the engine room, whether the mount welds hold or
not is probably going to be a secondary issue...

Richard

Its just gotta last long enough for me to get it on the ground ;-)

Blueskies wrote:
I meant while the part was in service. If an engine mount was brazed, and there was an engine fire, would the braze
joint fail (come apart) where a welded one would hold?



Dunno, Mongo.

I guess it would depend on how hot for how long.

But remember that it takes an acetylene flame to braze in the first
place.

If if gets that hot in the engine room, whether the mount welds hold or
not is probably going to be a secondary issue...

Richard

Its just gotta last long enough for me to get it on the ground ;-)




Getting it on the ground is no problem, gravity will help you with that
task, now doing it in a survivable manner, that is the trick.

George

"George" wrote in message . net...
Blueskies wrote:
I meant while the part was in service. If an engine mount was brazed, and there was an engine fire, would the braze
joint fail (come apart) where a welded one would hold?



Dunno, Mongo.

I guess it would depend on how hot for how long.

But remember that it takes an acetylene flame to braze in the first
place.

If if gets that hot in the engine room, whether the mount welds hold or
not is probably going to be a secondary issue...

Richard

Its just gotta last long enough for me to get it on the ground ;-)




Getting it on the ground is no problem, gravity will help you with that task, now doing it in a survivable manner,
that is the trick.

George

Reminds me of the guy with the souped up O-200 formula racer. The engine was putting out great power at something like
3200 rpm, till it threw a prop blade at something like 2000' agl... Shook real bad and tore the engine off the mount,
but the safety cable kept it from coming loose from the airframe, so he was able to get it back on the ground "in a
survivable manner". If it had broken completely loose the CG would have been way off and that would have been the end of
it...

Same thing with a fire in flight. I would at least want the engine to hang on for a while to give me a fighting
chance...

On Wed, 02 Jan 2008 13:22:24 GMT, "Blueskies"
wrote:


"Richard Riley" wrote in message ...
On Fri, 28 Dec 2007 19:46:57 -0800 (PST), "
wrote:

On Dec 28, 2:57 pm, wright1902glider wrote:
the author
seems to think that 4130 cro-mo steel can't be welded with an oxy-
acetylene torch.
--------------------------------------------------------------------------------

Pure bull****. Indeed, for the stresses encountered in bicycles
(which is what he's talking about) there are any number of BRAZING
compounds that yield joints stronger than than normalized 4130.

O/A does just fine airframes... and for bike frames.

If brazing gives stronger joints that normalized 4130, why aren't we
brazing airframes?

(I'm not saying it's an incorrect statement - I know better than to
disagree with VD on something like this. I just figure there must be
a reason, like the brazing compounds are more expensive.)


Won't withstand high temperatures?

Will withstand temperatures higher than anything attatched to the
airframe will ever withstand.

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