I'm trying to make something like this:

http://sports.webshots.com/photo/121...44194919ClRBmi
http://sports.webshots.com/photo/121...44194919EvrnCe

and am not sure what sort of aluminum to use. The person who made
that descibers it as:

"I carefully and gradually bent them over my thigh. The material is
1/4" x 1.5" aluminum that I bought at a hardware store and the bases
are just two layers of 3/4" plywood laminated together. When I bent
them, I just eyeballed the curves and left the ends longer than I
needed, so I could adjust the shape."

I have the choice of buying 2024-T4 or 6061 T6 -- will either of these
work? What would be more durable?

Thanks in advance for any advice.

JT

"John Forrest Tomlinson" wrote in message
...
I'm trying to make something like this:

http://sports.webshots.com/photo/121...44194919ClRBmi
http://sports.webshots.com/photo/121...44194919EvrnCe

and am not sure what sort of aluminum to use. The person who made
that descibers it as:

"I carefully and gradually bent them over my thigh. The material is
1/4" x 1.5" aluminum that I bought at a hardware store and the bases
are just two layers of 3/4" plywood laminated together. When I bent
them, I just eyeballed the curves and left the ends longer than I
needed, so I could adjust the shape."

I have the choice of buying 2024-T4 or 6061 T6 -- will either of these
work? What would be more durable?

Thanks in advance for any advice.

JT

2024 is roughly twice as strong as 6061, but it doesn't bend well. Just
eyeballing that job, I wouldn't trust 2024 for the application.

Either one is probably a lot stronger than you need. By the looks of the
other photos, the task is limited more by spring flexure than by strength.
And the springiness (Young's modulus) of both grades of aluminum is the
same.

BTW, bending even 6061 over your thigh may give you more trouble than you
think. Whatever that guy bought at a hardware store was not likely to be
either 6061 or 2024. It probably was 5052 or 3003, or maybe even one of the
1100-series grades. All of them are a lot weaker than 6061.

--
Ed Huntress

On Tue, 17 Feb 2009 21:48:28 -0500, "Ed Huntress"
wrote:


"John Forrest Tomlinson" wrote in message
.. .
I'm trying to make something like this:

http://sports.webshots.com/photo/121...44194919ClRBmi
http://sports.webshots.com/photo/121...44194919EvrnCe

and am not sure what sort of aluminum to use. The person who made
that descibers it as:

"I carefully and gradually bent them over my thigh. The material is
1/4" x 1.5" aluminum that I bought at a hardware store and the bases
are just two layers of 3/4" plywood laminated together. When I bent
them, I just eyeballed the curves and left the ends longer than I
needed, so I could adjust the shape."

I have the choice of buying 2024-T4 or 6061 T6 -- will either of these
work? What would be more durable?

Thanks in advance for any advice.

JT

2024 is roughly twice as strong as 6061, but it doesn't bend well. Just
eyeballing that job, I wouldn't trust 2024 for the application.

Either one is probably a lot stronger than you need. By the looks of the
other photos, the task is limited more by spring flexure than by strength.
And the springiness (Young's modulus) of both grades of aluminum is the
same.

BTW, bending even 6061 over your thigh may give you more trouble than you
think. Whatever that guy bought at a hardware store was not likely to be
either 6061 or 2024. It probably was 5052 or 3003, or maybe even one of the
1100-series grades. All of them are a lot weaker than 6061.

Thanks! That's exactly the info I was looking for.

JT

On Wed, 18 Feb 2009 02:59:41 GMT, John Forrest Tomlinson
wrote:

On Tue, 17 Feb 2009 21:48:28 -0500, "Ed Huntress"
wrote:


"John Forrest Tomlinson" wrote in message
. ..
I'm trying to make something like this:

http://sports.webshots.com/photo/121...44194919ClRBmi
http://sports.webshots.com/photo/121...44194919EvrnCe

and am not sure what sort of aluminum to use. The person who made
that descibers it as:

"I carefully and gradually bent them over my thigh. The material is
1/4" x 1.5" aluminum that I bought at a hardware store and the bases
are just two layers of 3/4" plywood laminated together. When I bent
them, I just eyeballed the curves and left the ends longer than I
needed, so I could adjust the shape."

I have the choice of buying 2024-T4 or 6061 T6 -- will either of these
work? What would be more durable?

Thanks in advance for any advice.

JT

2024 is roughly twice as strong as 6061, but it doesn't bend well. Just
eyeballing that job, I wouldn't trust 2024 for the application.

Either one is probably a lot stronger than you need. By the looks of the
other photos, the task is limited more by spring flexure than by strength.
And the springiness (Young's modulus) of both grades of aluminum is the
same.

BTW, bending even 6061 over your thigh may give you more trouble than you
think. Whatever that guy bought at a hardware store was not likely to be
either 6061 or 2024. It probably was 5052 or 3003, or maybe even one of the
1100-series grades. All of them are a lot weaker than 6061.

Thanks! That's exactly the info I was looking for.

JT

It's generally called "utility grade" or possibly "architectural"
aluminum. Non weldable(generally) and not heat treatable

wrote in message
...
On Wed, 18 Feb 2009 02:59:41 GMT, John Forrest Tomlinson
wrote:

On Tue, 17 Feb 2009 21:48:28 -0500, "Ed Huntress"
wrote:


"John Forrest Tomlinson" wrote in message
...
I'm trying to make something like this:

http://sports.webshots.com/photo/121...44194919ClRBmi
http://sports.webshots.com/photo/121...44194919EvrnCe

and am not sure what sort of aluminum to use. The person who made
that descibers it as:

"I carefully and gradually bent them over my thigh. The material is
1/4" x 1.5" aluminum that I bought at a hardware store and the bases
are just two layers of 3/4" plywood laminated together. When I bent
them, I just eyeballed the curves and left the ends longer than I
needed, so I could adjust the shape."

I have the choice of buying 2024-T4 or 6061 T6 -- will either of these
work? What would be more durable?

Thanks in advance for any advice.

JT

2024 is roughly twice as strong as 6061, but it doesn't bend well. Just
eyeballing that job, I wouldn't trust 2024 for the application.

Either one is probably a lot stronger than you need. By the looks of the
other photos, the task is limited more by spring flexure than by
strength.
And the springiness (Young's modulus) of both grades of aluminum is the
same.

BTW, bending even 6061 over your thigh may give you more trouble than you
think. Whatever that guy bought at a hardware store was not likely to be
either 6061 or 2024. It probably was 5052 or 3003, or maybe even one of
the
1100-series grades. All of them are a lot weaker than 6061.

Thanks! That's exactly the info I was looking for.

JT

It's generally called "utility grade" or possibly "architectural"
aluminum. Non weldable(generally) and not heat treatable

The decorative and architectural grades are often specialty grades in the
1000 series. They're very corrosion-resistant, bright, and relatively weak,
and they're often chosen for their extrudability (1050, 1060, 1100, rarely
1350, and custom alloys made for extrusion).

But you never know what you're getting in a hardware store. If it's 1100, it
is easily weldable. The same is true with 1060, if that's what you have.
Some of the custom architectural alloys can be more difficult.

--
Ed Huntress

"John Forrest Tomlinson" wrote in message
...
I'm trying to make something like this:

http://sports.webshots.com/photo/121...44194919ClRBmi
http://sports.webshots.com/photo/121...44194919EvrnCe

and am not sure what sort of aluminum to use. The person who made
that descibers it as:

"I carefully and gradually bent them over my thigh. The material is
1/4" x 1.5" aluminum that I bought at a hardware store and the bases
are just two layers of 3/4" plywood laminated together. When I bent
them, I just eyeballed the curves and left the ends longer than I
needed, so I could adjust the shape."

I have the choice of buying 2024-T4 or 6061 T6 -- will either of these
work? What would be more durable?

Thanks in advance for any advice.

JT

6063 aluminum is commonly used for extrusions and forms, and is likely the
alloy you'll encounter at a commercial outlet such as HD or such. It
bends fairly easily.

Aluminum in a T6 condition (such as 6061) isn't likely to bend without a
struggle, so if you find it's hard to bend, and you have a torch at your
disposal, smoke the aluminum with an acetylene flame, then heat it gently
until the soot ignites. Don't heat beyond, you'll be near the melting point.
I agree---avoid 2024.

The heating process mentioned will anneal the aluminum, allowing it to be
bent easier. You will not be able to restore the T6 condition, so if you
want the part to be rigid, this isn't a good idea.

Harold

"Harold and Susan Vordos" wrote in message
.. .

"John Forrest Tomlinson" wrote in message
...
I'm trying to make something like this:

http://sports.webshots.com/photo/121...44194919ClRBmi
http://sports.webshots.com/photo/121...44194919EvrnCe

and am not sure what sort of aluminum to use. The person who made
that descibers it as:

"I carefully and gradually bent them over my thigh. The material is
1/4" x 1.5" aluminum that I bought at a hardware store and the bases
are just two layers of 3/4" plywood laminated together. When I bent
them, I just eyeballed the curves and left the ends longer than I
needed, so I could adjust the shape."

I have the choice of buying 2024-T4 or 6061 T6 -- will either of these
work? What would be more durable?

Thanks in advance for any advice.

JT

6063 aluminum is commonly used for extrusions and forms, and is likely the
alloy you'll encounter at a commercial outlet such as HD or such. It
bends fairly easily.

Aluminum in a T6 condition (such as 6061) isn't likely to bend without a
struggle, so if you find it's hard to bend, and you have a torch at your
disposal, smoke the aluminum with an acetylene flame, then heat it gently
until the soot ignites. Don't heat beyond, you'll be near the melting
point. I agree---avoid 2024.

The heating process mentioned will anneal the aluminum, allowing it to be
bent easier. You will not be able to restore the T6 condition, so if
you want the part to be rigid, this isn't a good idea.

Harold

Oh, boy, we're going to confuse John good, now. Yes, there's a good chance
that what he'd find in that kind of section is 6063. The 1000-series alloys
used for smaller decorative extrusions and trim aren't commonly available in
the form of a 1/4"-thick strap; that's more likely to be among the odds and
ends made for structural architectural use -- window and door frames,
mostly, and railings or pipes made for hand railings and such, which are
primarily 6063. It's possible that's all that might be available in the
rather long pieces he needs for this project.

That is, if he were buying it from a consumer retail source. Since he says
that his choices are 2024-T4 or 6061-T6, he's likely getting it directly or
indirectly from an aluminum service center. So, between those two, I'd go
with 6061.

I didn't think about the fact that he's stuck with material that's in the T6
condition -- 40 ksi yield -- which would be more than a little difficult to
bend over one's thigh. g That would be like bending mild steel. He'll
probably need the torch (775 deg. F for full anneal) or a simple bending
jig.

--
Ed Huntress

On Wed, 18 Feb 2009 03:06:07 -0500, "Ed Huntress"
wrote:

Oh, boy, we're going to confuse John good, now. Yes, there's a good chance
that what he'd find in that kind of section is 6063. The 1000-series alloys
used for smaller decorative extrusions and trim aren't commonly available in
the form of a 1/4"-thick strap; that's more likely to be among the odds and
ends made for structural architectural use -- window and door frames,
mostly, and railings or pipes made for hand railings and such, which are
primarily 6063. It's possible that's all that might be available in the
rather long pieces he needs for this project.

That is, if he were buying it from a consumer retail source. Since he says
that his choices are 2024-T4 or 6061-T6, he's likely getting it directly or
indirectly from an aluminum service center. So, between those two, I'd go
with 6061.

Thanks everyone.

The 6061 T6 is fairly cheap online (onlinemetals.com), so I might try
that and if it doesn't work I can live with it.

But I might first look around for 6063 or something more easily bent
at a big hardware store .

JT

On Wed, 18 Feb 2009 10:31:00 GMT, John Forrest Tomlinson
wrote:

On Wed, 18 Feb 2009 03:06:07 -0500, "Ed Huntress"
wrote:

Oh, boy, we're going to confuse John good, now. Yes, there's a good chance
that what he'd find in that kind of section is 6063. The 1000-series alloys
used for smaller decorative extrusions and trim aren't commonly available in
the form of a 1/4"-thick strap; that's more likely to be among the odds and
ends made for structural architectural use -- window and door frames,
mostly, and railings or pipes made for hand railings and such, which are
primarily 6063. It's possible that's all that might be available in the
rather long pieces he needs for this project.

That is, if he were buying it from a consumer retail source. Since he says
that his choices are 2024-T4 or 6061-T6, he's likely getting it directly or
indirectly from an aluminum service center. So, between those two, I'd go
with 6061.

Thanks everyone.

The 6061 T6 is fairly cheap online (onlinemetals.com), so I might try
that and if it doesn't work I can live with it.

But I might first look around for 6063 or something more easily bent
at a big hardware store .

It's the T6 part that'll getcha - the stuff that is pre-tempered.
Beg, borrow, Garage Sale, steal or (Gasp!) buy an oxy-acetylene torch
rig to heat up the aluminum and take the temper out of it before you
bend, and you'll be good to go. If you don't, you'll see it cracking
at the bend right before your eyes.

You could use a Propane or MAPP torch, but you can't use the soot
and burn trick as easily. Might have to get the Tempstik paint marker
that changes color when it reaches the target temperature - mark the
front side and heat the back side with the torch while watching the
mark for the change.

WARNING - the temperature spread from 'annealed' to 'melted' isn't
very much on aluminum. Too much heat, and you have a shiny puddle.

The 'B' Acetylene and 50 CF Oxygen cylinders are the smallest
practical size for around the home shop, when you balance purchase
price and refill price with how much work they will do on a fill.

Forget the little "tote torches" that take the 10 cubic foot Oxygen
and 'MC' Acetylene. They work for brazing up refrigeration lines, but
the bottles are too small to do any Real Work - you can't use large
tips because there is a withdrawal rate limit on the Acetylene bottle
of 1/7 capacity per hour or you start sucking out the Acetone. And
just when the work starts getting warm, the tanks go empty.

-- Bruce --

On Wed, 18 Feb 2009 08:27:22 -0800, Bruce L. Bergman
wrote:



It's the T6 part that'll getcha - the stuff that is pre-tempered.
Beg, borrow, Garage Sale, steal or (Gasp!) buy an oxy-acetylene torch
rig to heat up the aluminum and take the temper out of it before you
bend, and you'll be good to go. If you don't, you'll see it cracking
at the bend right before your eyes.

As long as the bend radius is greater than 3/4" or so there won't be
any cracking in 6061-T6. The bend radius in the photo in the original
post was much larger.

--
Ned Simmons

"Ned Simmons" wrote in message
...
On Wed, 18 Feb 2009 08:27:22 -0800, Bruce L. Bergman
wrote:



It's the T6 part that'll getcha - the stuff that is pre-tempered.
Beg, borrow, Garage Sale, steal or (Gasp!) buy an oxy-acetylene torch
rig to heat up the aluminum and take the temper out of it before you
bend, and you'll be good to go. If you don't, you'll see it cracking
at the bend right before your eyes.

As long as the bend radius is greater than 3/4" or so there won't be
any cracking in 6061-T6. The bend radius in the photo in the original
post was much larger.

--
Ned Simmons

Yeah, but he isn't going to bend 1/4" stock at 40 ksi yield over his thigh,
either, unless he has steel thighs. He'd need some kind of jig.

Also, given the way aluminum anneals, annealing it with a torch in a way
that's sufficiently uniform to get a smooth bend, to match the tip of the
ski, is problematic unless he has some experience torch-annealing the stuff.
If he has to work with T6, I'd make a wooden bending jig for the job.

--
Ed Huntress

On Wed, 18 Feb 2009 13:07:31 -0500, "Ed Huntress"
wrote:


"Ned Simmons" wrote in message
.. .
On Wed, 18 Feb 2009 08:27:22 -0800, Bruce L. Bergman
wrote:



It's the T6 part that'll getcha - the stuff that is pre-tempered.
Beg, borrow, Garage Sale, steal or (Gasp!) buy an oxy-acetylene torch
rig to heat up the aluminum and take the temper out of it before you
bend, and you'll be good to go. If you don't, you'll see it cracking
at the bend right before your eyes.

As long as the bend radius is greater than 3/4" or so there won't be
any cracking in 6061-T6. The bend radius in the photo in the original
post was much larger.

--
Ned Simmons

Yeah, but he isn't going to bend 1/4" stock at 40 ksi yield over his thigh,
either, unless he has steel thighs. He'd need some kind of jig.


1/4 x 1-1/2 will bend at 625 lb-in. A 30" length centered on your
thigh would bend with 40 pounds applied to the ends, which doesn't
seem unreasonable for someone of average strength. Goalie pads might
help with the thigh bruises g.

--
Ned Simmons

Ed Huntress wrote:
"Ned Simmons" wrote in message
...

On Wed, 18 Feb 2009 08:27:22 -0800, Bruce L. Bergman
wrote:



It's the T6 part that'll getcha - the stuff that is pre-tempered.
Beg, borrow, Garage Sale, steal or (Gasp!) buy an oxy-acetylene torch
rig to heat up the aluminum and take the temper out of it before you
bend, and you'll be good to go. If you don't, you'll see it cracking
at the bend right before your eyes.

As long as the bend radius is greater than 3/4" or so there won't be
any cracking in 6061-T6. The bend radius in the photo in the original
post was much larger.

--
Ned Simmons


Yeah, but he isn't going to bend 1/4" stock at 40 ksi yield over his thigh,
either, unless he has steel thighs. He'd need some kind of jig.

Also, given the way aluminum anneals, annealing it with a torch in a way
that's sufficiently uniform to get a smooth bend, to match the tip of the
ski, is problematic unless he has some experience torch-annealing the stuff.
If he has to work with T6, I'd make a wooden bending jig for the job.

--
Ed Huntress



I've bent 2" x 3/8" 60??-T6 (6062 in the UK maybe as common alloys can
vary from country to country) around a chipboard former at about 5"
radius. I used some 2" square box section about 6' long to get the
leverage to bend it through 90 degrees, main thing was that the spring
back meant bending through about 120 degrees and the resultant bend
radius was about 6". It was determined by try and error. Annealing the
alloy would make it much more specific where the bend was done and much
less force required. I wouldn't have thought that a portable waxing
table would require that close a bend to support the skis. Been so many
years since I waxed cross country skis at the site that I can't remember
what we used to hold them.

On Wed, 18 Feb 2009 06:54:58 GMT, "Harold and Susan Vordos"
wrote:


"John Forrest Tomlinson" wrote in message
.. .
I'm trying to make something like this:

http://sports.webshots.com/photo/121...44194919ClRBmi
http://sports.webshots.com/photo/121...44194919EvrnCe

and am not sure what sort of aluminum to use. The person who made
that descibers it as:

"I carefully and gradually bent them over my thigh. The material is
1/4" x 1.5" aluminum that I bought at a hardware store and the bases
are just two layers of 3/4" plywood laminated together. When I bent
them, I just eyeballed the curves and left the ends longer than I
needed, so I could adjust the shape."

I have the choice of buying 2024-T4 or 6061 T6 -- will either of these
work? What would be more durable?

Thanks in advance for any advice.

JT

6063 aluminum is commonly used for extrusions and forms, and is likely the
alloy you'll encounter at a commercial outlet such as HD or such. It
bends fairly easily.

Aluminum in a T6 condition (such as 6061) isn't likely to bend without a
struggle, so if you find it's hard to bend, and you have a torch at your
disposal, smoke the aluminum with an acetylene flame, then heat it gently
until the soot ignites. Don't heat beyond, you'll be near the melting point.
I agree---avoid 2024.

The heating process mentioned will anneal the aluminum, allowing it to be
bent easier. You will not be able to restore the T6 condition, so if you
want the part to be rigid, this isn't a good idea.

Harold

T6 is an "aged" condition, and in about 6 months or less, the aluminum
is bact very close to T6.

Bruce L. Bergman wrote:
John Forrest Tomlinson wrote:

The 6061 T6 is fairly cheap online (onlinemetals.com), so I might try
that and if it doesn't work I can live with it.

But I might first look around for 6063 or something more easily bent
at a big hardware store .

It's the T6 part that'll getcha - the stuff that is pre-tempered.
Beg, borrow, Garage Sale, steal or (Gasp!) buy an oxy-acetylene torch
rig to heat up the aluminum and take the temper out of it before you
bend, and you'll be good to go. If you don't, you'll see it cracking
at the bend right before your eyes.

You could use a Propane or MAPP torch, but you can't use the soot
and burn trick as easily. Might have to get the Tempstik paint marker
that changes color when it reaches the target temperature - mark the
front side and heat the back side with the torch while watching the
mark for the change.

WARNING - the temperature spread from 'annealed' to 'melted' isn't
very much on aluminum. Too much heat, and you have a shiny puddle.

The 'B' Acetylene and 50 CF Oxygen cylinders are the smallest
practical size for around the home shop, when you balance purchase
price and refill price with how much work they will do on a fill.

Forget the little "tote torches" that take the 10 cubic foot Oxygen
and 'MC' Acetylene. They work for brazing up refrigeration lines, but
the bottles are too small to do any Real Work - you can't use large
tips because there is a withdrawal rate limit on the Acetylene bottle
of 1/7 capacity per hour or you start sucking out the Acetone. And
just when the work starts getting warm, the tanks go empty.

-- Bruce --

Take a part used bar of ordinary white hand soap (a new bar is a little
too hard, you could moisten it and leave it to the next day) and streak
the surface of the aluminium. Heat from the other side with any sort of
gas torch or even a gas hob. When the soap smear goes a good brown
colour, its done and you quench it in water. If you let it go black,
you overheated it, but you've still got a little margin before it turns
into a nasty puddle.

Been there, done it with minimal tools, made up an internal sleeve to
pop rivet in place to repair a racing dinghy mast that's still in use 5
years later.
We did get the broken outer tube welded as well, but it was rather
'daubed' and didn't look like it would have carried the load alone. We
waited a month before putting it in service as we didn't have the
facilities to artificially age a long tube.


If you *can* reheat it to 350 degrees F (175 degrees C) and hold it
there for 6 hours, you'll age it most of the way back towards T6
condition. As it was annealed pretty crudely and definitely wasn't
held at the proper solution treatment temperature for the correct length
of time it isn't going to be quite as good, so you might only attain T4
equivalent but for a non-critical application it'll do fine. Dont over
heat it, better to err slightly under rather than over.

Even holding it at about 100 degrees C for about 24 hours would be
beneficial and *anyone* can arrange to do that in a water bath or steam
chest.

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:

wrote in message
...
On Wed, 18 Feb 2009 06:54:58 GMT, "Harold and Susan Vordos"
wrote:


"John Forrest Tomlinson" wrote in message
. ..
I'm trying to make something like this:

http://sports.webshots.com/photo/121...44194919ClRBmi
http://sports.webshots.com/photo/121...44194919EvrnCe

and am not sure what sort of aluminum to use. The person who made
that descibers it as:

"I carefully and gradually bent them over my thigh. The material is
1/4" x 1.5" aluminum that I bought at a hardware store and the bases
are just two layers of 3/4" plywood laminated together. When I bent
them, I just eyeballed the curves and left the ends longer than I
needed, so I could adjust the shape."

I have the choice of buying 2024-T4 or 6061 T6 -- will either of these
work? What would be more durable?

Thanks in advance for any advice.

JT

6063 aluminum is commonly used for extrusions and forms, and is likely the
alloy you'll encounter at a commercial outlet such as HD or such. It
bends fairly easily.

Aluminum in a T6 condition (such as 6061) isn't likely to bend without a
struggle, so if you find it's hard to bend, and you have a torch at your
disposal, smoke the aluminum with an acetylene flame, then heat it gently
until the soot ignites. Don't heat beyond, you'll be near the melting
point.
I agree---avoid 2024.

The heating process mentioned will anneal the aluminum, allowing it to be
bent easier. You will not be able to restore the T6 condition, so if
you
want the part to be rigid, this isn't a good idea.

Harold

T6 is an "aged" condition, and in about 6 months or less, the aluminum
is bact very close to T6.

No, it won't. Only if it is solution annealed first will it return.

Harold