I'm kinda thinking of making a model airplane muffler or two. These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong
(or nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On 2010-09-13, Tim Wescott wrote:
I'm kinda thinking of making a model airplane muffler or two. These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong
(or nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.


You can weld aluminum with O/A.

i

On Sep 12, 8:13*pm, Tim Wescott wrote:

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. *See some examples hehttp://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. *But it'll all be aluminum, so how
to join the pieces?



Tim Wescott
Wescott Design Serviceshttp://www.wescottdesign.com


Could you use machine screws to hold the header to the front machined
end? And then run a threaded rod through the tube to hold the
machined ends.

Or use lost wax casting to make it as one piece.

Dan

wrote:
On Sep 12, 8:13 pm, Tim Wescott wrote:

These things have a header that comes off of the engine, then goes
into
a tube-shaped expansion chamber. See some examples
hehttp://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined
header,
machined ends, and a section of tube. But it'll all be aluminum, so
how
to join the pieces?



Tim Wescott
Wescott Design Serviceshttp://www.wescottdesign.com


Could you use machine screws to hold the header to the front machined
end? And then run a threaded rod through the tube to hold the
machined ends.

Or use lost wax casting to make it as one piece.

Dan

That could be cast with a simple core . For that matter , if it's one that
has the inlet port at 90° to the main muffler , cast it as a solid , machine
the interior , cap the front with a threaded dome . Built an R/C boat once
upon a time . While I was saving up for the radio gear it "got broke" . Long
story ...

--
Snag
Hobby Caster

"Tim Wescott" wrote in message
...
I'm kinda thinking of making a model airplane muffler or two. These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong
(or nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.


I've used aluminum solder with success. The hard part is to keep the
base aluminum from forming an oxide coating before the solder flows.
I don't know what the solder metal is but my file tells me it is harder
than aluminum. I bought the rods at ace HW which were similar to
these.
http://www.plumbersurplus.com/Prod/B...u=313530363035
Art

"Tim Wescott" wrote in message
...
I'm kinda thinking of making a model airplane muffler or two. These days
the things are generally cast in one piece -- but that isn't going to work
for a one-off.

These things have a header that comes off of the engine, then goes into a
tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off. But
I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong (or
nearly so) as the parent material and that can be done on a welding bench
with a torch and a vise.

TIA.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

I have done just a little aluminum brazing. The tricky thing is that it
does not flow into gaps (unless there is a technique using flux I do not
know about). You scrape the surface with the rod and it will stick where
scraped. You can also deposit a blob and then spread it as you scrape with a
screwdriver or wire brush. You can tin both sides before assembling and
then press together while melting. Be very careful about melting the parts
themselves. The braze melting point is only slightly lower than the
aluminum.

--FWIW try making a model engine muffler using wood and epoxy; I've
seen it done and the accoustics are ...interesting.

--
"Steamboat Ed" Haas : Beauty times brains
Hacking the Trailing Edge! : is a constant..
www.nmpproducts.com
---Decks a-wash in a sea of words---

On Sep 12, 5:13*pm, Tim Wescott wrote:
I'm kinda thinking of making a model airplane muffler or two. *These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. *See some examples hehttp://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. *But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? *What sort of selection do I
have as far as difficulty vs. results goes? *Brands to look for? *Avoid?
* Places to get stuff? *I'd like something that's going to be as strong
(or nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.

--

Tim Wescott
Wescott Design Serviceshttp://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details athttp://www.wescottdesign.com/actfes/actfes.html

Hi, Tim.

JB Weld will easily take 650 degree F. Will change color, though.

Paul

Tim Wescott wrote:
I'm kinda thinking of making a model airplane muffler or two. These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong
(or nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.


I have welded a LOT of aluminum with O/A. Just need to use the same
allow for filler as you have for sheet stock. O/A was the preferred
method for joining a lot of aluminum items for years. Once you get it
down as a skill it's a LOT of fun. Plus with the O/A you can easily
remove stresses in the finished product.


--
Steve W.
(\___/)
(='.'=)
(")_(")

On 09/12/2010 08:05 PM, Steve W. wrote:
Tim Wescott wrote:
I'm kinda thinking of making a model airplane muffler or two. These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong
(or nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.


I have welded a LOT of aluminum with O/A. Just need to use the same
allow for filler as you have for sheet stock. O/A was the preferred
method for joining a lot of aluminum items for years. Once you get it
down as a skill it's a LOT of fun. Plus with the O/A you can easily
remove stresses in the finished product.

Part of the reason I want to braze is because I have a lot of odds and
ends that aren't necessarily going to be easy-to-weld alloys, no matter
how nice they are to machine.

But I'll leave your suggestion in the back of my mind -- it's a good
one, and if there are such I can just stock up on alloys that are easy
to both weld and machine.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On 09/12/2010 05:57 PM, Snag wrote:
wrote:
On Sep 12, 8:13 pm, Tim wrote:

These things have a header that comes off of the engine, then goes
into
a tube-shaped expansion chamber. See some examples
hehttp://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined
header,
machined ends, and a section of tube. But it'll all be aluminum, so
how
to join the pieces?



Tim Wescott
Wescott Design Serviceshttp://www.wescottdesign.com


Could you use machine screws to hold the header to the front machined
end? And then run a threaded rod through the tube to hold the
machined ends.

Or use lost wax casting to make it as one piece.

Dan

That could be cast with a simple core . For that matter , if it's one that
has the inlet port at 90° to the main muffler , cast it as a solid , machine
the interior , cap the front with a threaded dome . Built an R/C boat once
upon a time . While I was saving up for the radio gear it "got broke" . Long
story ...

You would have to suggest that. And here I have a Vibration & Stratton
engine that's just crying out to be broken into bits and recycled as all
sorts of nifty stuff.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On Sun, 12 Sep 2010 22:19:57 -0700, Tim Wescott
wrote:

You would have to suggest that. And here I have a Vibration & Stratton
engine that's just crying out to be broken into bits and recycled as all
sorts of nifty stuff.

You meant to say "Briggs and ScrapEm" engine, right?

--
Not merely an absence of noise, Real Silence begins
when a reasonable being withdraws from the noise in
order to find peace and order in his inner sanctuary.
-- Peter Minard

On 09/13/2010 03:42 AM, Snag wrote:
Tim Wescott wrote:
On 09/12/2010 05:57 PM, Snag wrote:
wrote:
On Sep 12, 8:13 pm, Tim wrote:

These things have a header that comes off of the engine, then goes
into
a tube-shaped expansion chamber. See some examples
hehttp://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined
header,
machined ends, and a section of tube. But it'll all be aluminum, so
how
to join the pieces?



Tim Wescott
Wescott Design Serviceshttp://www.wescottdesign.com


Could you use machine screws to hold the header to the front
machined end? And then run a threaded rod through the tube to hold
the machined ends.

Or use lost wax casting to make it as one piece.

Dan

That could be cast with a simple core . For that matter , if it's
one that has the inlet port at 90° to the main muffler , cast it as
a solid , machine the interior , cap the front with a threaded dome
. Built an R/C boat once upon a time . While I was saving up for the
radio gear it "got broke" . Long story ...

You would have to suggest that. And here I have a Vibration&
Stratton engine that's just crying out to be broken into bits and
recycled as all sorts of nifty stuff.

--

Tim Wescott

I've got 5 car/truck rims awaiting cool weather ... when they will join
the rest of the wheelium , extrudium , and OldChevyHeadium as ingots .
Do you subscribe to any of the hobby casting email lists ?

No! No no no no no no no!

When I retire, maybe yes. But not now -- I have other things that are
higher in the priority list than starting my own backyard foundry.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On 09/13/2010 04:31 AM, Pete Keillor wrote:
On Sun, 12 Sep 2010 22:19:07 -0700, Tim
wrote:

On 09/12/2010 08:05 PM, Steve W. wrote:
Tim Wescott wrote:
I'm kinda thinking of making a model airplane muffler or two. These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong
(or nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.


I have welded a LOT of aluminum with O/A. Just need to use the same
allow for filler as you have for sheet stock. O/A was the preferred
method for joining a lot of aluminum items for years. Once you get it
down as a skill it's a LOT of fun. Plus with the O/A you can easily
remove stresses in the finished product.

Part of the reason I want to braze is because I have a lot of odds and
ends that aren't necessarily going to be easy-to-weld alloys, no matter
how nice they are to machine.

But I'll leave your suggestion in the back of my mind -- it's a good
one, and if there are such I can just stock up on alloys that are easy
to both weld and machine.

I assume you've ruled out mousse can mufflers, or the equivalent Bud
beer bottle mufflers?
http://www.rcuniverse.com/forum/m_73...tm.htm#7419797

The engine in question is .19 cubic inch, not 1.9.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On Mon, 13 Sep 2010 11:36:04 -0500, Pete Keillor
wrote:

On Mon, 13 Sep 2010 09:15:54 -0700, Tim Wescott
wrote:

On 09/13/2010 04:31 AM, Pete Keillor wrote:
On Sun, 12 Sep 2010 22:19:07 -0700, Tim
wrote:

On 09/12/2010 08:05 PM, Steve W. wrote:
Tim Wescott wrote:
I'm kinda thinking of making a model airplane muffler or two. These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong
(or nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.


I have welded a LOT of aluminum with O/A. Just need to use the same
allow for filler as you have for sheet stock. O/A was the preferred
method for joining a lot of aluminum items for years. Once you get it
down as a skill it's a LOT of fun. Plus with the O/A you can easily
remove stresses in the finished product.

Part of the reason I want to braze is because I have a lot of odds and
ends that aren't necessarily going to be easy-to-weld alloys, no matter
how nice they are to machine.

But I'll leave your suggestion in the back of my mind -- it's a good
one, and if there are such I can just stock up on alloys that are easy
to both weld and machine.

I assume you've ruled out mousse can mufflers, or the equivalent Bud
beer bottle mufflers?
http://www.rcuniverse.com/forum/m_73...tm.htm#7419797

The engine in question is .19 cubic inch, not 1.9.

Ahh, then about like one of those 5hr energy drinks.
How about reworking a CO2 cartridge?

On 09/13/2010 05:32 PM, wrote:
On Mon, 13 Sep 2010 11:36:04 -0500, Pete Keillor
wrote:

On Mon, 13 Sep 2010 09:15:54 -0700, Tim
wrote:

On 09/13/2010 04:31 AM, Pete Keillor wrote:
On Sun, 12 Sep 2010 22:19:07 -0700, Tim
wrote:

On 09/12/2010 08:05 PM, Steve W. wrote:
Tim Wescott wrote:
I'm kinda thinking of making a model airplane muffler or two. These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong
(or nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.


I have welded a LOT of aluminum with O/A. Just need to use the same
allow for filler as you have for sheet stock. O/A was the preferred
method for joining a lot of aluminum items for years. Once you get it
down as a skill it's a LOT of fun. Plus with the O/A you can easily
remove stresses in the finished product.

Part of the reason I want to braze is because I have a lot of odds and
ends that aren't necessarily going to be easy-to-weld alloys, no matter
how nice they are to machine.

But I'll leave your suggestion in the back of my mind -- it's a good
one, and if there are such I can just stock up on alloys that are easy
to both weld and machine.

I assume you've ruled out mousse can mufflers, or the equivalent Bud
beer bottle mufflers?
http://www.rcuniverse.com/forum/m_73...tm.htm#7419797

The engine in question is .19 cubic inch, not 1.9.

Ahh, then about like one of those 5hr energy drinks.
How about reworking a CO2 cartridge?

Weight. Not a bad idea, otherwise.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On Mon, 13 Sep 2010 17:42:08 -0500, "RogerN"
wrote:


"Steve W." wrote in message
...
RogerN wrote:
I have welded a LOT of aluminum with O/A. Just need to use the same
allow for filler as you have for sheet stock. O/A was the preferred
method for joining a lot of aluminum items for years. Once you get it
down as a skill it's a LOT of fun. Plus with the O/A you can easily
remove stresses in the finished product.


--
Steve W.
(\___/)
(='.'=)
(")_(")


Isn't there a flux you use with O/A on aluminum? Our local hardware
store
used to stock it years ago IIRC but today they just have brazing and
soldering flux.

RogerN



Yes. I have a couple depending on what the material is. Aufhauser Flux10
and Flux14 plus there is some Forney AlumAflux as well. May have some
real old powder stuff as well.

Aluminum is an interesting material to weld. Too cold and it doesn't
weld, too hot and you get a puddle at your feet!

--
Steve W.

I think my flux was probably by Forney, that's the brand of welding stuff
the hardware store sold. I welded aluminum once using a carbon arc torch on
my AC electric welder. It worked but I didn't do it enough to get skilled,
just got a couple of pieces to stick together.

I like how the TIG works compared to my other experiences. The aluminum
gets a bright clean molten puddle. My other aluminum welding experience is
that the aluminum gets molten inside of a skin that is not molten, kind of
have to poke the rod through the skin and weld the aluminum underneath.
Note I haven't tried anything other than TIG since learning about cleaning
with the SS wire brush and alcohol, I'm sure a good cleaning would help the
results with oxy/acetylene or carbon arc.

RogerN

Flux is necessary for welding ally with torch -- or carbon arc.

On Mon, 13 Sep 2010 20:32:10 -0400, wrote:

On Mon, 13 Sep 2010 11:36:04 -0500, Pete Keillor
wrote:

On Mon, 13 Sep 2010 09:15:54 -0700, Tim Wescott
wrote:

On 09/13/2010 04:31 AM, Pete Keillor wrote:
On Sun, 12 Sep 2010 22:19:07 -0700, Tim
wrote:

On 09/12/2010 08:05 PM, Steve W. wrote:
Tim Wescott wrote:
I'm kinda thinking of making a model airplane muffler or two. These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong
(or nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.


I have welded a LOT of aluminum with O/A. Just need to use the same
allow for filler as you have for sheet stock. O/A was the preferred
method for joining a lot of aluminum items for years. Once you get it
down as a skill it's a LOT of fun. Plus with the O/A you can easily
remove stresses in the finished product.

Part of the reason I want to braze is because I have a lot of odds and
ends that aren't necessarily going to be easy-to-weld alloys, no matter
how nice they are to machine.

But I'll leave your suggestion in the back of my mind -- it's a good
one, and if there are such I can just stock up on alloys that are easy
to both weld and machine.

I assume you've ruled out mousse can mufflers, or the equivalent Bud
beer bottle mufflers?
http://www.rcuniverse.com/forum/m_73...tm.htm#7419797

The engine in question is .19 cubic inch, not 1.9.

Ahh, then about like one of those 5hr energy drinks.
How about reworking a CO2 cartridge?


I guess I'd have to ask "why aluminum". Back in the day we used to
build expansion chamber exhausts with very thin brass sheet, soft
soldered. for both .29 and .19 cu.in. engines. Granted these were for
control line speed but still ....

Cheers,

John D. Slocomb
(jdslocombatgmail)

On 09/14/2010 04:19 AM, J. D. Slocomb wrote:
On Mon, 13 Sep 2010 20:32:10 -0400, wrote:

On Mon, 13 Sep 2010 11:36:04 -0500, Pete Keillor
wrote:

On Mon, 13 Sep 2010 09:15:54 -0700, Tim
wrote:

On 09/13/2010 04:31 AM, Pete Keillor wrote:
On Sun, 12 Sep 2010 22:19:07 -0700, Tim
wrote:

On 09/12/2010 08:05 PM, Steve W. wrote:
Tim Wescott wrote:
I'm kinda thinking of making a model airplane muffler or two. These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong
(or nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.


I have welded a LOT of aluminum with O/A. Just need to use the same
allow for filler as you have for sheet stock. O/A was the preferred
method for joining a lot of aluminum items for years. Once you get it
down as a skill it's a LOT of fun. Plus with the O/A you can easily
remove stresses in the finished product.

Part of the reason I want to braze is because I have a lot of odds and
ends that aren't necessarily going to be easy-to-weld alloys, no matter
how nice they are to machine.

But I'll leave your suggestion in the back of my mind -- it's a good
one, and if there are such I can just stock up on alloys that are easy
to both weld and machine.

I assume you've ruled out mousse can mufflers, or the equivalent Bud
beer bottle mufflers?
http://www.rcuniverse.com/forum/m_73...tm.htm#7419797

The engine in question is .19 cubic inch, not 1.9.

Ahh, then about like one of those 5hr energy drinks.
How about reworking a CO2 cartridge?


I guess I'd have to ask "why aluminum".

Uh, because that's what you get with a new motor these days?

Gee, that seems like such a solid reason...

Back in the day we used to
build expansion chamber exhausts with very thin brass sheet, soft
soldered. for both .29 and .19 cu.in. engines. Granted these were for
control line speed but still ....

I'll consider that. Aluminum looks niftier, though.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On 09/13/2010 09:14 PM, Don Foreman wrote:
On Mon, 13 Sep 2010 17:42:08 -0500,
wrote:


"Steve wrote in message
...
RogerN wrote:
I have welded a LOT of aluminum with O/A. Just need to use the same
allow for filler as you have for sheet stock. O/A was the preferred
method for joining a lot of aluminum items for years. Once you get it
down as a skill it's a LOT of fun. Plus with the O/A you can easily
remove stresses in the finished product.


--
Steve W.
(\___/)
(='.'=)
(")_(")


Isn't there a flux you use with O/A on aluminum? Our local hardware
store
used to stock it years ago IIRC but today they just have brazing and
soldering flux.

RogerN



Yes. I have a couple depending on what the material is. Aufhauser Flux10
and Flux14 plus there is some Forney AlumAflux as well. May have some
real old powder stuff as well.

Aluminum is an interesting material to weld. Too cold and it doesn't
weld, too hot and you get a puddle at your feet!

--
Steve W.

I think my flux was probably by Forney, that's the brand of welding stuff
the hardware store sold. I welded aluminum once using a carbon arc torch on
my AC electric welder. It worked but I didn't do it enough to get skilled,
just got a couple of pieces to stick together.

I like how the TIG works compared to my other experiences. The aluminum
gets a bright clean molten puddle. My other aluminum welding experience is
that the aluminum gets molten inside of a skin that is not molten, kind of
have to poke the rod through the skin and weld the aluminum underneath.
Note I haven't tried anything other than TIG since learning about cleaning
with the SS wire brush and alcohol, I'm sure a good cleaning would help the
results with oxy/acetylene or carbon arc.

RogerN
(Damn my news provider for dropping messages)

My understanding is that aluminum oxidizes so readily that _any_ process
that isn't shielded is going to have that oxide layer.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On Tue, 14 Sep 2010 07:28:01 -0700, Tim Wescott
wrote:

On 09/13/2010 09:14 PM, Don Foreman wrote:
On Mon, 13 Sep 2010 17:42:08 -0500,
wrote:


"Steve wrote in message
...
RogerN wrote:
I have welded a LOT of aluminum with O/A. Just need to use the same
allow for filler as you have for sheet stock. O/A was the preferred
method for joining a lot of aluminum items for years. Once you get it
down as a skill it's a LOT of fun. Plus with the O/A you can easily
remove stresses in the finished product.


--
Steve W.
(\___/)
(='.'=)
(")_(")


Isn't there a flux you use with O/A on aluminum? Our local hardware
store
used to stock it years ago IIRC but today they just have brazing and
soldering flux.

RogerN



Yes. I have a couple depending on what the material is. Aufhauser Flux10
and Flux14 plus there is some Forney AlumAflux as well. May have some
real old powder stuff as well.

Aluminum is an interesting material to weld. Too cold and it doesn't
weld, too hot and you get a puddle at your feet!

--
Steve W.

I think my flux was probably by Forney, that's the brand of welding stuff
the hardware store sold. I welded aluminum once using a carbon arc torch on
my AC electric welder. It worked but I didn't do it enough to get skilled,
just got a couple of pieces to stick together.

I like how the TIG works compared to my other experiences. The aluminum
gets a bright clean molten puddle. My other aluminum welding experience is
that the aluminum gets molten inside of a skin that is not molten, kind of
have to poke the rod through the skin and weld the aluminum underneath.
Note I haven't tried anything other than TIG since learning about cleaning
with the SS wire brush and alcohol, I'm sure a good cleaning would help the
results with oxy/acetylene or carbon arc.

RogerN
(Damn my news provider for dropping messages)

My understanding is that aluminum oxidizes so readily that _any_ process
that isn't shielded is going to have that oxide layer.

That's why flux is necessary.

On 09/12/2010 05:13 PM, Tim Wescott wrote:
I'm kinda thinking of making a model airplane muffler or two. These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong (or
nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.


Update: the local welding shop has an aluminum soldering kit and
aluminum brazing flux, but was out of aluminum brazing rod. They had
some zinc-alloy rod that may or may not have worked with the aluminum
brazing flux, in a size way bigger than my job.

So I got the soldering kit.

I'm going to see how well the soldering process works -- if it seems
almost but not quite strong enough then I'll try brazing, if it works a
charm I won't change.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On Tue, 14 Sep 2010 14:06:46 -0700, Tim Wescott
wrote:

On 09/12/2010 05:13 PM, Tim Wescott wrote:
I'm kinda thinking of making a model airplane muffler or two. These
days the things are generally cast in one piece -- but that isn't going
to work for a one-off.

These things have a header that comes off of the engine, then goes into
a tube-shaped expansion chamber. See some examples he
http://www.mecoa.com/kb/aero/aircraft.htm

I'm thinking that I can fabricate one of these with a machined header,
machined ends, and a section of tube. But it'll all be aluminum, so how
to join the pieces?

I'm assuming that JB weld won't take the heat and will just fall off.
But I'm ready to be corrected.

I don't have a TIG welder, or I'd just select TIGable materials and be
happy.

I do have an oxy-acetylene set, and I certainly know how to solder.

So -- will aluminum brazing work on this? What sort of selection do I
have as far as difficulty vs. results goes? Brands to look for? Avoid?
Places to get stuff? I'd like something that's going to be as strong (or
nearly so) as the parent material and that can be done on a welding
bench with a torch and a vise.

TIA.


Update: the local welding shop has an aluminum soldering kit and
aluminum brazing flux, but was out of aluminum brazing rod. They had
some zinc-alloy rod that may or may not have worked with the aluminum
brazing flux, in a size way bigger than my job.

So I got the soldering kit.

I'm going to see how well the soldering process works -- if it seems
almost but not quite strong enough then I'll try brazing, if it works a
charm I won't change.
I've got about 3 lbs of AluSol sitting in the garage - flux cored
solder for aluminum.

"Tim Wescott" wrote in message
...


Update: the local welding shop has an aluminum soldering kit and
aluminum brazing flux, but was out of aluminum brazing rod. They had
some zinc-alloy rod that may or may not have worked with the aluminum
brazing flux, in a size way bigger than my job.

So I got the soldering kit.

I'm going to see how well the soldering process works -- if it seems
almost but not quite strong enough then I'll try brazing, if it works a
charm I won't change.

--

Tim Wescott

As you have an OA torch it seems to me that if you use a reducing
flame the aluminum will have less of an opportunity to form an oxide
coating and may solder easier. Expert opinion anyone?
Art

On 09/14/2010 06:08 PM, Artemus wrote:
"Tim wrote in message
...


Update: the local welding shop has an aluminum soldering kit and
aluminum brazing flux, but was out of aluminum brazing rod. They had
some zinc-alloy rod that may or may not have worked with the aluminum
brazing flux, in a size way bigger than my job.

So I got the soldering kit.

I'm going to see how well the soldering process works -- if it seems
almost but not quite strong enough then I'll try brazing, if it works a
charm I won't change.

--

Tim Wescott

As you have an OA torch it seems to me that if you use a reducing
flame the aluminum will have less of an opportunity to form an oxide
coating and may solder easier. Expert opinion anyone?

AFAIK that would only slow things down. Keep in mind that aluminum is
so electronegative that it'll reduce rust back to iron, and produce
enough heat in the process to melt the iron to steel (think "thermite
welding"). I don't know if it can reduce CO or CO2, but I wouldn't be
surprised.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On Tue, 14 Sep 2010 14:34:57 -0700, Tim Wescott
wrote:

On 09/14/2010 02:30 PM, Rich Grise wrote:
On Sun, 12 Sep 2010 17:13:41 -0700, Tim Wescott wrote:

I'm not a machinist or a weldor, so I'd make something that could
be simply bolted together.

[C'mon, Rich. You're at least a wannabe machinist if you're here on
Wreck.Metalheads.]


That's Plan B.

But brazed or soldered looks cooler, and should be lighter.

Yeah, screw "functional". Just make it -look- cool!

--
Not merely an absence of noise, Real Silence begins
when a reasonable being withdraws from the noise in
order to find peace and order in his inner sanctuary.
-- Peter Minard

On 09/14/2010 09:03 PM, Paul Hovnanian P.E. wrote:
Tim Wescott wrote:

On 09/14/2010 06:08 PM, Artemus wrote:
"Tim wrote in message
...


Update: the local welding shop has an aluminum soldering kit and
aluminum brazing flux, but was out of aluminum brazing rod. They had
some zinc-alloy rod that may or may not have worked with the aluminum
brazing flux, in a size way bigger than my job.

So I got the soldering kit.

I'm going to see how well the soldering process works -- if it seems
almost but not quite strong enough then I'll try brazing, if it works a
charm I won't change.

--

Tim Wescott

As you have an OA torch it seems to me that if you use a reducing
flame the aluminum will have less of an opportunity to form an oxide
coating and may solder easier. Expert opinion anyone?

AFAIK that would only slow things down. Keep in mind that aluminum is
so electronegative that it'll reduce rust back to iron, and produce
enough heat in the process to melt the iron to steel (think "thermite
welding"). I don't know if it can reduce CO or CO2, but I wouldn't be
surprised.

Aluminum can be gas welded. Its tricky. You have to get the right kind
of flux nd the correct filer rod for the alloy you're working with.
Preparation is important, as is adjusting the flame correctly. But it is
do-able.

If I were going out and buying new material for this project I'd
probably do just that. But cost _is_ an object, and I have boxes full
of surplus parts from a former employer that are all nicely machinable
aluminum in unknown alloys (well, probably 6061 and some 2xxx alloy or
another). Since I have no clue about the weldability if the various
bits, and I'm not interested in spending money on a bunch of new bits,
soldering or brazing is the process of choice.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On 09/15/2010 07:23 AM, Larry Jaques wrote:
On Tue, 14 Sep 2010 14:34:57 -0700, Tim
wrote:

On 09/14/2010 02:30 PM, Rich Grise wrote:
On Sun, 12 Sep 2010 17:13:41 -0700, Tim Wescott wrote:

I'm not a machinist or a weldor, so I'd make something that could
be simply bolted together.

[C'mon, Rich. You're at least a wannabe machinist if you're here on
Wreck.Metalheads.]


That's Plan B.

But brazed or soldered looks cooler, and should be lighter.

Yeah, screw "functional". Just make it -look- cool!

It's gotta look cool _and_ work. Beauty comes from functionality: if it
works, it is, by definition, beautiful. If it works _and_ it's well
made it's beautifuller. If it doesn't work worth a damn then all the
artsy-fartsy critics in the world can rave over it, but it's still an
ugly piece of @#$%.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

"Tim Wescott" wrote in message
news

As you have an OA torch it seems to me that if you use a reducing
flame the aluminum will have less of an opportunity to form an oxide
coating and may solder easier. Expert opinion anyone?

AFAIK that would only slow things down. Keep in mind that aluminum is
so electronegative that it'll reduce rust back to iron, and produce
enough heat in the process to melt the iron to steel (think "thermite
welding"). I don't know if it can reduce CO or CO2, but I wouldn't be
surprised.

--

Tim Wescott

That's a good point. I don't know either but it would be easy and quick
to test.
Art

On Wed, 15 Sep 2010 14:27:24 -0700, "Artemus"
wrote:


"Tim Wescott" wrote in message
news

As you have an OA torch it seems to me that if you use a reducing
flame the aluminum will have less of an opportunity to form an oxide
coating and may solder easier. Expert opinion anyone?

AFAIK that would only slow things down. Keep in mind that aluminum is
so electronegative that it'll reduce rust back to iron, and produce
enough heat in the process to melt the iron to steel (think "thermite
welding"). I don't know if it can reduce CO or CO2, but I wouldn't be
surprised.

--

Tim Wescott

That's a good point. I don't know either but it would be easy and quick
to test.
Art

The zinc type alubraze rods work pretty good - I've used "3.4.1
ideal rod" from amrelle Sales in Whitby Ontario to make canoe racks,
bicycle racks tor the back of my camper trailer and a bunch of other
stuff and have never had a joint failure.

On 09/15/2010 04:27 PM, Paul Hovnanian P.E. wrote:
Tim Wescott wrote:

On 09/14/2010 09:03 PM, Paul Hovnanian P.E. wrote:
Tim Wescott wrote:

On 09/14/2010 06:08 PM, Artemus wrote:
"Tim wrote in message
...


Update: the local welding shop has an aluminum soldering kit and
aluminum brazing flux, but was out of aluminum brazing rod. They had
some zinc-alloy rod that may or may not have worked with the aluminum
brazing flux, in a size way bigger than my job.

So I got the soldering kit.

I'm going to see how well the soldering process works -- if it seems
almost but not quite strong enough then I'll try brazing, if it works a
charm I won't change.

--

Tim Wescott

As you have an OA torch it seems to me that if you use a reducing
flame the aluminum will have less of an opportunity to form an oxide
coating and may solder easier. Expert opinion anyone?

AFAIK that would only slow things down. Keep in mind that aluminum is
so electronegative that it'll reduce rust back to iron, and produce
enough heat in the process to melt the iron to steel (think "thermite
welding"). I don't know if it can reduce CO or CO2, but I wouldn't be
surprised.

Aluminum can be gas welded. Its tricky. You have to get the right kind
of flux nd the correct filer rod for the alloy you're working with.
Preparation is important, as is adjusting the flame correctly. But it is
do-able.

If I were going out and buying new material for this project I'd
probably do just that. But cost _is_ an object, and I have boxes full
of surplus parts from a former employer that are all nicely machinable
aluminum in unknown alloys (well, probably 6061 and some 2xxx alloy or
another). Since I have no clue about the weldability if the various
bits, and I'm not interested in spending money on a bunch of new bits,
soldering or brazing is the process of choice.

That makes sense. The strength welding will get you probably isn't
needed in your application. You might want to check on the max temp.
your assembly will see and compare that to the soldering or brazing
process you are using.

Having burnt myself numerous times on glow engines I can attest that
they often get to 'Ouch', but rarely do they get to '@#$%ing Ouch'.
Mufflers will go up to 'shiny spot'.

This is silver solder, which if I'm not mistaken melts way up there
around 'browned spot' if not 'burnt black'. So I think I'm OK.

At any rate, we'll test it when we get it on the engine :-).

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On Wed, 15 Sep 2010 16:27:54 -0700, "Paul Hovnanian P.E."
wrote:

Tim Wescott wrote:

On 09/14/2010 09:03 PM, Paul Hovnanian P.E. wrote:
Tim Wescott wrote:

On 09/14/2010 06:08 PM, Artemus wrote:
"Tim wrote in message
...


Update: the local welding shop has an aluminum soldering kit and
aluminum brazing flux, but was out of aluminum brazing rod. They had
some zinc-alloy rod that may or may not have worked with the aluminum
brazing flux, in a size way bigger than my job.

So I got the soldering kit.

I'm going to see how well the soldering process works -- if it seems
almost but not quite strong enough then I'll try brazing, if it works a
charm I won't change.

--

Tim Wescott

As you have an OA torch it seems to me that if you use a reducing
flame the aluminum will have less of an opportunity to form an oxide
coating and may solder easier. Expert opinion anyone?

AFAIK that would only slow things down. Keep in mind that aluminum is
so electronegative that it'll reduce rust back to iron, and produce
enough heat in the process to melt the iron to steel (think "thermite
welding"). I don't know if it can reduce CO or CO2, but I wouldn't be
surprised.

Aluminum can be gas welded. Its tricky. You have to get the right kind
of flux nd the correct filer rod for the alloy you're working with.
Preparation is important, as is adjusting the flame correctly. But it is
do-able.

If I were going out and buying new material for this project I'd
probably do just that. But cost _is_ an object, and I have boxes full
of surplus parts from a former employer that are all nicely machinable
aluminum in unknown alloys (well, probably 6061 and some 2xxx alloy or
another). Since I have no clue about the weldability if the various
bits, and I'm not interested in spending money on a bunch of new bits,
soldering or brazing is the process of choice.

That makes sense. The strength welding will get you probably isn't
needed in your application. You might want to check on the max temp.
your assembly will see and compare that to the soldering or brazing
process you are using.
Melt temp on the 3.4.1 Ideal rod is 715 to 735 F

On Wed, 15 Sep 2010 08:44:21 -0700, Tim Wescott
wrote:

On 09/15/2010 07:23 AM, Larry Jaques wrote:
On Tue, 14 Sep 2010 14:34:57 -0700, Tim
wrote:

On 09/14/2010 02:30 PM, Rich Grise wrote:
On Sun, 12 Sep 2010 17:13:41 -0700, Tim Wescott wrote:

I'm not a machinist or a weldor, so I'd make something that could
be simply bolted together.

[C'mon, Rich. You're at least a wannabe machinist if you're here on
Wreck.Metalheads.]


That's Plan B.

But brazed or soldered looks cooler, and should be lighter.

Yeah, screw "functional". Just make it -look- cool!

It's gotta look cool _and_ work. Beauty comes from functionality: if it
works, it is, by definition, beautiful. If it works _and_ it's well
made it's beautifuller. If it doesn't work worth a damn then all the
artsy-fartsy critics in the world can rave over it, but it's still an
ugly piece of @#$%.

I wholeheartedly agree.

--
Not merely an absence of noise, Real Silence begins
when a reasonable being withdraws from the noise in
order to find peace and order in his inner sanctuary.
-- Peter Minard