I have long been of the opinion that, if you have to rely on glue for
attaching something to aluminum, you should rethink your design.

I am changing my mind.

A little over a year ago, an artist friend of mine asked me to help her out.

She had been having photographs printed large (24"x32"), having them mounted
to a sheet of aluminum. and attaching a frame made of 1" sq alum tube to the
back to act as a stand off when hung on a wall.

The outfit she had been using in Milwaukee to do the work, got shut down on
an OSHA beef and she wanted me to do the final assembly.

She tells me she has that she has bought the special glue and dispenser that
they were using.

"Wait a minute!" I sez, "Aluminum and glue don't mix"

But somebody else has already done it and this isn't a life safety
application. So, I call an engineer at Lord Adhesives to ask him about
application techniques.

I ask him if I have to sand the metal, or etch, or use some special primer,
and he sez "No,".

"This stuff is specially designed to work with dirty metal. That's why it
works well on aluminum. You don't need any special surface prep. You don't
want chunks of dirt or dripping oil, but finger prints and light oxides are
not a problem."

Well it worked a treat.

Months later I have another aluminum job. This one needs me to rivet the
short edge of some 1/2"x 1.25" anodized alum glass channel to 6 ft long
1.75" anodized aluminum angles. The channels are attached perpendicular to
the angle and I used the adhesive to glue them temporarily to the angle
while I drilled the rivet holes.

There was only a 1/2"x1" glue surface on each one (2 per angle, 144 angles)
but despite rough handling not a single one got knocked off.

Last week I had another aluminum job.

A small museum without a lot of money, needs some stands made. After
talking the designer out of some grandiose ideas, I point to the aluminum
angle falloff from the other job, and say, "I can make you some out of that
real cheap.".

The design we ended up with was a bunch of simple, flat, angle frames about
16" square.

The corners were simple lap joints with a short piece of angle mounted in
the inside of the corners to act as a gusset.

I figured that I would glue it and rivet it like the other assembly. but,
when the glue was set, the joints were so strong that the rivets were a
waste if time.

I did some more research and this glue has a shear strength of 475 psi. That
means each glued corner has roughly the same strength as if it were put
together with 16 standard strength 1/8" solid alum rivets. I have a spare
frame here, that I have been sitting on and rocking back and forth. The
angle flexes, but no sign of glue failure.

Anyway, this stuff was Lord #406-19, a two part acrylic adhesive. It costs
about $13 bucks a tube and because of a 4-1 mix ratio you need a special
glue dispensing gun.

I am not affiliated with the company, just an impressed consumer.

Paul K. Dickman

"Paul K. Dickman" wrote in message
...
I have long been of the opinion that, if you have to rely on glue for
attaching something to aluminum, you should rethink your design.

I am changing my mind.

A little over a year ago, an artist friend of mine asked me to help her
out.

She had been having photographs printed large (24"x32"), having them
mounted
to a sheet of aluminum. and attaching a frame made of 1" sq alum tube to
the
back to act as a stand off when hung on a wall.

The outfit she had been using in Milwaukee to do the work, got shut down
on
an OSHA beef and she wanted me to do the final assembly.

She tells me she has that she has bought the special glue and dispenser
that
they were using.

"Wait a minute!" I sez, "Aluminum and glue don't mix"

But somebody else has already done it and this isn't a life safety
application. So, I call an engineer at Lord Adhesives to ask him about
application techniques.

I ask him if I have to sand the metal, or etch, or use some special
primer,
and he sez "No,".

"This stuff is specially designed to work with dirty metal. That's why it
works well on aluminum. You don't need any special surface prep. You don't
want chunks of dirt or dripping oil, but finger prints and light oxides
are
not a problem."

Well it worked a treat.

Months later I have another aluminum job. This one needs me to rivet the
short edge of some 1/2"x 1.25" anodized alum glass channel to 6 ft long
1.75" anodized aluminum angles. The channels are attached perpendicular to
the angle and I used the adhesive to glue them temporarily to the angle
while I drilled the rivet holes.

There was only a 1/2"x1" glue surface on each one (2 per angle, 144
angles)
but despite rough handling not a single one got knocked off.

Last week I had another aluminum job.

A small museum without a lot of money, needs some stands made. After
talking the designer out of some grandiose ideas, I point to the aluminum
angle falloff from the other job, and say, "I can make you some out of
that
real cheap.".

The design we ended up with was a bunch of simple, flat, angle frames
about
16" square.

The corners were simple lap joints with a short piece of angle mounted in
the inside of the corners to act as a gusset.

I figured that I would glue it and rivet it like the other assembly. but,
when the glue was set, the joints were so strong that the rivets were a
waste if time.

I did some more research and this glue has a shear strength of 475 psi.
That
means each glued corner has roughly the same strength as if it were put
together with 16 standard strength 1/8" solid alum rivets. I have a spare
frame here, that I have been sitting on and rocking back and forth. The
angle flexes, but no sign of glue failure.

Anyway, this stuff was Lord #406-19, a two part acrylic adhesive. It costs
about $13 bucks a tube and because of a 4-1 mix ratio you need a special
glue dispensing gun.

I am not affiliated with the company, just an impressed consumer.

Paul K. Dickman

I watched Modern Marvels last night. A program I had recorded sometime ago
about adhesives. They showed this really miraculous 3M adhesive tape for any
metal to metal or other adhesion that would knock any number of rivets out
of the ballpark. Something something 8 --- need to sharpen the brain.

Very cool!

On Sep 29, 5:46 pm, "Wayne Lundberg"
wrote:
"Paul K. Dickman" wrote in ...

I have long been of the opinion that, if you have to rely on glue for
attaching something to aluminum, you should rethink your design.

I am changing my mind.

A little over a year ago, an artist friend of mine asked me to help her
out.

She had been having photographs printed large (24"x32"), having them
mounted
to a sheet of aluminum. and attaching a frame made of 1" sq alum tube to
the
back to act as a stand off when hung on a wall.

The outfit she had been using in Milwaukee to do the work, got shut down
on
an OSHA beef and she wanted me to do the final assembly.

She tells me she has that she has bought the special glue and dispenser
that
they were using.

"Wait a minute!" I sez, "Aluminum and glue don't mix"

But somebody else has already done it and this isn't a life safety
application. So, I call an engineer at Lord Adhesives to ask him about
application techniques.

I ask him if I have to sand the metal, or etch, or use some special
primer,
and he sez "No,".

"This stuff is specially designed to work with dirty metal. That's why it
works well on aluminum. You don't need any special surface prep. You don't
want chunks of dirt or dripping oil, but finger prints and light oxides
are
not a problem."

Well it worked a treat.

Months later I have another aluminum job. This one needs me to rivet the
short edge of some 1/2"x 1.25" anodized alum glass channel to 6 ft long
1.75" anodized aluminum angles. The channels are attached perpendicular to
the angle and I used the adhesive to glue them temporarily to the angle
while I drilled the rivet holes.

There was only a 1/2"x1" glue surface on each one (2 per angle, 144
angles)
but despite rough handling not a single one got knocked off.

Last week I had another aluminum job.

A small museum without a lot of money, needs some stands made. After
talking the designer out of some grandiose ideas, I point to the aluminum
angle falloff from the other job, and say, "I can make you some out of
that
real cheap.".

The design we ended up with was a bunch of simple, flat, angle frames
about
16" square.

The corners were simple lap joints with a short piece of angle mounted in
the inside of the corners to act as a gusset.

I figured that I would glue it and rivet it like the other assembly. but,
when the glue was set, the joints were so strong that the rivets were a
waste if time.

I did some more research and this glue has a shear strength of 475 psi.
That
means each glued corner has roughly the same strength as if it were put
together with 16 standard strength 1/8" solid alum rivets. I have a spare
frame here, that I have been sitting on and rocking back and forth. The
angle flexes, but no sign of glue failure.

Anyway, this stuff was Lord #406-19, a two part acrylic adhesive. It costs
about $13 bucks a tube and because of a 4-1 mix ratio you need a special
glue dispensing gun.

I am not affiliated with the company, just an impressed consumer.

Paul K. Dickman

I watched Modern Marvels last night. A program I had recorded sometime ago
about adhesives. They showed this really miraculous 3M adhesive tape for any
metal to metal or other adhesion that would knock any number of rivets out
of the ballpark. Something something 8 --- need to sharpen the brain.

Very cool!

Airliners are glued together, specifically wings.

Epoxy cement on clean aluminum has a tensile strength of 4,000 PSI.:
LePages 24 hr cure, hardware store, type stuff.

Would I trust my life on a home-baked glue joint? Probably
not....well, maybe if properly tested.

Wolfgang

wrote:


Airliners are glued together, specifically wings.

Epoxy cement on clean aluminum has a tensile strength of 4,000 PSI.:
LePages 24 hr cure, hardware store, type stuff.

Would I trust my life on a home-baked glue joint? Probably
not....well, maybe if properly tested.

Wolfgang



My BS meter is pegged!

On Sep 29, 11:08 pm, cavelamb himself wrote:
wrote:

Airliners are glued together, specifically wings.

Epoxy cement on clean aluminum has a tensile strength of 4,000 PSI.:
LePages 24 hr cure, hardware store, type stuff.

Would I trust my life on a home-baked glue joint? Probably
not....well, maybe if properly tested.

Wolfgang

My BS meter is pegged!

Well, oh wise one, why don't you educate us ignorant folks with your
deep insight in the fabrication of airliners and the application of
epoxy adhesive!!

Wolfgang

wrote:

On Sep 29, 11:08 pm, cavelamb himself wrote:

wrote:


Airliners are glued together, specifically wings.

Epoxy cement on clean aluminum has a tensile strength of 4,000 PSI.:
LePages 24 hr cure, hardware store, type stuff.

Would I trust my life on a home-baked glue joint? Probably
not....well, maybe if properly tested.

Wolfgang

My BS meter is pegged!


Well, oh wise one, why don't you educate us ignorant folks with your
deep insight in the fabrication of airliners and the application of
epoxy adhesive!!

Wolfgang


No.

Don't think I'll take that bait, Wolfie.

Research it yer own bad self...


Richard

On Sat, 29 Sep 2007 22:09:22 -0700, wrote:

On Sep 29, 11:08 pm, cavelamb himself wrote:
wrote:

Airliners are glued together, specifically wings.

Epoxy cement on clean aluminum has a tensile strength of 4,000 PSI.:
LePages 24 hr cure, hardware store, type stuff.

Would I trust my life on a home-baked glue joint? Probably
not....well, maybe if properly tested.

Wolfgang

My BS meter is pegged!

Well, oh wise one, why don't you educate us ignorant folks with your
deep insight in the fabrication of airliners and the application of
epoxy adhesive!!

Wolfgang

unless you are glueing in an inert atmosphere after removing all
surface oxide you are actually just gluing to the oxide layer.
how strong is that oxide bonded to the underlying aluminium?

Stealth Pilot

On Sep 29, 5:59 pm, wrote:
On Sep 29, 5:46 pm, "Wayne Lundberg"
wrote:



"Paul K. Dickman" wrote in ...

I have long been of the opinion that, if you have to rely on glue for
attaching something to aluminum, you should rethink your design.

I am changing my mind.

A little over a year ago, an artist friend of mine asked me to help her
out.

She had been having photographs printed large (24"x32"), having them
mounted
to a sheet of aluminum. and attaching a frame made of 1" sq alum tube to
the
back to act as a stand off when hung on a wall.

The outfit she had been using in Milwaukee to do the work, got shut down
on
an OSHA beef and she wanted me to do the final assembly.

She tells me she has that she has bought the special glue and dispenser
that
they were using.

"Wait a minute!" I sez, "Aluminum and glue don't mix"

But somebody else has already done it and this isn't a life safety
application. So, I call an engineer at Lord Adhesives to ask him about
application techniques.

I ask him if I have to sand the metal, or etch, or use some special
primer,
and he sez "No,".

"This stuff is specially designed to work with dirty metal. That's why it
works well on aluminum. You don't need any special surface prep. You don't
want chunks of dirt or dripping oil, but finger prints and light oxides
are
not a problem."

Well it worked a treat.

Months later I have another aluminum job. This one needs me to rivet the
short edge of some 1/2"x 1.25" anodized alum glass channel to 6 ft long
1.75" anodized aluminum angles. The channels are attached perpendicular to
the angle and I used the adhesive to glue them temporarily to the angle
while I drilled the rivet holes.

There was only a 1/2"x1" glue surface on each one (2 per angle, 144
angles)
but despite rough handling not a single one got knocked off.

Last week I had another aluminum job.

A small museum without a lot of money, needs some stands made. After
talking the designer out of some grandiose ideas, I point to the aluminum
angle falloff from the other job, and say, "I can make you some out of
that
real cheap.".

The design we ended up with was a bunch of simple, flat, angle frames
about
16" square.

The corners were simple lap joints with a short piece of angle mounted in
the inside of the corners to act as a gusset.

I figured that I would glue it and rivet it like the other assembly. but,
when the glue was set, the joints were so strong that the rivets were a
waste if time.

I did some more research and this glue has a shear strength of 475 psi.
That
means each glued corner has roughly the same strength as if it were put
together with 16 standard strength 1/8" solid alum rivets. I have a spare
frame here, that I have been sitting on and rocking back and forth. The
angle flexes, but no sign of glue failure.

Anyway, this stuff was Lord #406-19, a two part acrylic adhesive. It costs
about $13 bucks a tube and because of a 4-1 mix ratio you need a special
glue dispensing gun.

I am not affiliated with the company, just an impressed consumer.

Paul K. Dickman

I watched Modern Marvels last night. A program I had recorded sometime ago
about adhesives. They showed this really miraculous 3M adhesive tape for any
metal to metal or other adhesion that would knock any number of rivets out
of the ballpark. Something something 8 --- need to sharpen the brain.

Very cool!

Airliners are glued together, specifically wings.

Epoxy cement on clean aluminum has a tensile strength of 4,000 PSI.:
LePages 24 hr cure, hardware store, type stuff.

Would I trust my life on a home-baked glue joint? Probably
not....well, maybe if properly tested.

Wolfgang

I was building a homebuilt that had a number of aluminum fittings
bonded into the epoxy-glass structure. I had to sell it when my wife
found out what the engine was going to cost, but I did get to ride in
and fly another of the same design. As in any gluing operation,
cleanliness is next to godliness :-)

wrote in message
ups.com...

Airliners are glued together, specifically wings.

The cite for this, I gotta see. If you're speaking of Airbus, I can't
argue, but I've got many years of building Boeing widebodies, and your use
of the term "glue" is highly misleading.
Boeing's wings are bolted and riveted together, and the surfaces between
the parts are usually sealed (fay surface sealing) and that sealing does
contribute to some degree the strength of the joint, but it's not used in
the stress calculations. So, if in a joint there is both rivets and a
sealant, can you say it's been "glued?"

"Carl McIver" wrote in message
...
wrote in message
ups.com...

Airliners are glued together, specifically wings.

The cite for this, I gotta see. If you're speaking of Airbus, I can't
argue, but I've got many years of building Boeing widebodies, and your use
of the term "glue" is highly misleading.
Boeing's wings are bolted and riveted together, and the surfaces
between the parts are usually sealed (fay surface sealing) and that
sealing does contribute to some degree the strength of the joint, but it's
not used in the stress calculations. So, if in a joint there is both
rivets and a sealant, can you say it's been "glued?"

It usually is, Carl. The rivets, as they're used in rivet-bonding, are not
distributed as they would be in a joint that was riveted for maximum shear
strength. There usually are far fewer rivets than would be required to
provide much shear strength, and they're mostly located at the edges of the
sheets, in a line (more or less), which is not the way to gain maximum
strength.

High-strength adhesives in general have very high shear strength but poor
peel and cleavage strength. The rivets are there to keep the edges of the
aluminum from separating and loading the glue line in either peel or
cleavage.

I don't know specifically about Boeing but most commercial aircraft have
been rivet-bonded for more than two decades.

--
Ed Huntress

Ed Huntress wrote:

"Carl McIver" wrote in message
...

wrote in message
roups.com...

Airliners are glued together, specifically wings.

The cite for this, I gotta see. If you're speaking of Airbus, I can't
argue, but I've got many years of building Boeing widebodies, and your use
of the term "glue" is highly misleading.
Boeing's wings are bolted and riveted together, and the surfaces
between the parts are usually sealed (fay surface sealing) and that
sealing does contribute to some degree the strength of the joint, but it's
not used in the stress calculations. So, if in a joint there is both
rivets and a sealant, can you say it's been "glued?"


It usually is, Carl. The rivets, as they're used in rivet-bonding, are not
distributed as they would be in a joint that was riveted for maximum shear
strength. There usually are far fewer rivets than would be required to
provide much shear strength, and they're mostly located at the edges of the
sheets, in a line (more or less), which is not the way to gain maximum
strength.

High-strength adhesives in general have very high shear strength but poor
peel and cleavage strength. The rivets are there to keep the edges of the
aluminum from separating and loading the glue line in either peel or
cleavage.

I don't know specifically about Boeing but most commercial aircraft have
been rivet-bonded for more than two decades.

--
Ed Huntress



While there are aircraft that meet this description, Boeings are not
among them.

I believe you ae referring to the construction details more like on
Airbus aircraft.




Richard

Ed Huntress wrote:

High-strength adhesives in general have very high shear strength but poor
peel and cleavage strength. The rivets are there to keep the edges of the
aluminum from separating and loading the glue line in either peel or
cleavage.

That's the way it is.
Think of the rivet more to serve as a fixture while the glue is curing and
giving security for peel-off.


Nick
--
The lowcost-DRO:
http://www.yadro.de

Paul K. Dickman writes:

I did some more research and this glue has a shear strength of 475 psi.

The problem is that it doesn't fail in shear. More like peel.

Richard J Kinch wrote:

Paul K. Dickman writes:


I did some more research and this glue has a shear strength of 475 psi.


The problem is that it doesn't fail in shear. More like peel.

475 psi shear is pretty low...

"cavelamb himself" wrote in message
...
Richard J Kinch wrote:

Paul K. Dickman writes:


I did some more research and this glue has a shear strength of 475 psi.


The problem is that it doesn't fail in shear. More like peel.

475 psi shear is pretty low...

I'm sorry. I wasn't clear enough.

475psi wasn't the yield point. It was the UL rated strength for sign
applications, presumably derated with a suitable safety factor for loads
hung over the public way.

The yield point in lap shear is 2650 psi.
The peel strength is 25 pli.

Paul K. Dickman

On Sat, 29 Sep 2007 23:36:18 -0500, with neither quill nor qualm,
Richard J Kinch quickly quoth:

Paul K. Dickman writes:

I did some more research and this glue has a shear strength of 475 psi.

The problem is that it doesn't fail in shear. More like peel.

I've been using the industrial acrylic adhesive-backed velcro for my
glare guard product and it's simply amazing stuff; ten times as sticky
as the old stuff. The expensive stuff is surely ten times more stable
than this, too. I'm sold on acrylic adhesives. But on plane shells?
Shiver me timbers!

--
Exercise ferments the humors, casts them into their proper channels,
throws off redundancies, and helps nature in those secret distributions,
without which the body cannot subsist in its vigor, nor the soul act
with cheerfulness. -- Joseph Addison, The Spectator, July 12, 1711