Carbon Fiber 4 Dummies?



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W

Wile E.Coyote

Guest
Anyone know of any books or articles, on-line manuals etc. that show how to work with Carbon
Fiber...(for bike frames would be nice), but would settle for just learning the basics.
 
S

Skip

Guest
"Wile E.Coyote" <[email protected]> wrote in message
news:[email protected]...
> Anyone know of any books or articles, on-line manuals etc. that show how
to
> work with Carbon Fiber...(for bike frames would be nice), but would settle for just learning
> the basics.
>
I don't know of any a books about the process, but I can tell you I've been a factory that produced
Kestrel lookalike carbon fiber frames and the process wasn't pretty. I wouldn't want to work there
for even a day. yuch. Helped me appreciate steel frames.

skip
 

PaPa

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May 2, 2003
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There's very little difference between cf lay-ups and standard e-glass (fiberglass) lay-ups. Any current composties books/manuals will be valuable.
 
S

Steve McDonald

Guest
The most important basic about working with carbon fiber, is to leave it to those who have
professional quality protective masks. Dry carbon fiber (sometimes called graphite), when cut, gives
off some nasty little particles. Some of them are visible and may be filtered out by standard masks.
However, there are tiny bits that can't be seen, that fill the air and aren't removed by anything
but specialized masks. If you get them into your lungs, they may cause serious trouble. Not all the
long-term effects of these particles are yet known, but I decided years ago not to be a test dummy.

Carbon can give you more rigidity for an equal weight than most other materials. However, this
brittleness does not allow it to resist impacts and bending forces as well as other types of
fibers. It's something better suited to racing bikes that have a short service-life and
high-speed HPVs, than to practical street bicycles. A fiber called S-Glass is about twice as
strong as common fiberglass (E-Glass) and has similar layup characteristics. It's a good match
with epoxy resins and vinylester resins. My favorite for HPVs, Kayaks and other lightweight,
highly-loaded structures, is Dow Chemical's Derakane 8084, a special, rubberized vinylester.
Its cured molecular chains have 4 times the elongation potential and resistance to breaking as
common polyester resin and it also bonds 4 times as well. Contact Dow for information on the
industrial distributors of it, as it's only rarely found as an over-the-counter item. One of
its original purposes was to provide protective linings for pipelines that carry caustic fuels
and chemicals.

Dow also makes another type of vinylester resin, that is fire-resistant. It has a heavy
molecule, that is saturated with extra hydrogen atoms. These atoms fill in the "keyholes" that
would otherwise allow oxygen atoms to enter and combustion to occur at kindling temperature.
This resin is 20% heavier than standard types.

Steve McDonald
 
I

Ian Smith

Guest
On Thu, 8 May 2003 01:12:47, Steve McDonald <[email protected]> wrote:

> Carbon can give you more rigidity for an equal weight than most
> other materials. However, this brittleness does not allow it to resist

Stiffness is not synonymous with brittleness.

regards Ian SMith
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W

Wile E.Coyote

Guest
thanx I'll look into the alternative via Dow. "Steve McDonald" <[email protected]> wrote in
message news:[email protected]...
>
> The most important basic about working with carbon fiber, is to leave it to those who have
> professional quality protective masks. Dry carbon fiber (sometimes called graphite), when
> cut, gives off some nasty little particles. Some of them are visible and may be filtered out
> by standard masks. However, there are tiny bits that can't be seen, that fill the air and
> aren't removed by anything but specialized masks. If you get them into your lungs, they may
> cause serious trouble. Not all the long-term effects of these particles are yet known, but I
> decided years ago not to be a test dummy.
>
> Carbon can give you more rigidity for an equal weight than most other materials. However,
> this brittleness does not allow it to resist impacts and bending forces as well as other
> types of fibers. It's something better suited to racing bikes that have a short service-life
> and high-speed HPVs, than to practical street bicycles. A fiber called S-Glass is about twice
> as strong as common fiberglass (E-Glass) and has similar layup characteristics. It's a good
> match with epoxy resins and vinylester resins. My favorite for HPVs, Kayaks and other
> lightweight, highly-loaded structures, is Dow Chemical's Derakane 8084, a special, rubberized
> vinylester. Its cured molecular chains have 4 times the elongation potential and resistance
> to breaking as common polyester resin and it also bonds 4 times as well. Contact Dow for
> information on the industrial distributors of it, as it's only rarely found as an
> over-the-counter item. One of its original purposes was to provide protective linings for
> pipelines that carry caustic fuels and chemicals.
>
> Dow also makes another type of vinylester resin, that is fire-resistant. It has a heavy
> molecule, that is saturated with extra hydrogen atoms. These atoms fill in the "keyholes"
> that would otherwise allow oxygen atoms to enter and combustion to occur at kindling
> temperature. This resin is 20% heavier than standard types.
>
> Steve McDonald
 
J

Jeff Wills

Guest
"Wile E.Coyote" <[email protected]> wrote in message
news:<[email protected]>...
> Anyone know of any books or articles, on-line manuals etc. that show how to work with Carbon
> Fiber...(for bike frames would be nice), but would settle for just learning the basics.

As always, Sheldon Brown's site is a good place to start:
http://www.sheldonbrown.com/rinard/carbon_fiber.htm

A couple guys from the Portland Streamliner Gang will have homebuilt carbon fiber bikes (frames and
fairings) at the races coming up this month : http://www.ohpv.org/pir2003/2003race.htm such as
http://www.arborrhythms.com/~ben/hpvpir/images/faired39.jpg (large image!)

Jeff
 
R

Robert Haston

Guest
One piece of advice I have is to avoid trying to make a whole frame with it. Carbon tubes are made
with very exacting methods (low void, no bubbles, etc.) you can't match. They will be stronger,
lighter, and prettier.

Furthermore, clamping carbon cloth lugs to tubes is a far far easier process than laying up a frame.
http://www.calfeedesign.com/construction.shtml shows you how they make their custom lugged carbon
bikes. You can experiment with PVC and fiberglass until you get it right.

As to recumbents, carbon would best be suited to low racers. Carbon's stiffness allows thinner tubes
(to go between your legs) and is better for monotube construction. Although if you want a frame to
flex, titanium is best, and steel is proven. For items that aren't stiffness driven, such as seats
and such, fiberglass is stronger than steel.

You can also use carbon as a way to join or reinforce aluminum. Look out for galvanic corrosion -
west system's etch kit should work well enough. This also applies to joining crank brackets, etc.

As to sanding carbon fiber. First design around having to sand. Second, trimming off the excess with
scissors or a knife when the resin is firm is far easier and safer then sanding it when it is hard.
Wear a mask and goggles rated for it, wet sand (under a constant spray or wash if possible) and do
it outside in an area where the fibers won't collect and blow around when dried.

All that being said, I've screwed around with aluminum and steel, and done fiberglass projects. If
you don't have someone who can weld bikes for a decent price, a DIY carbon would be my
recommendation.

"Wile E.Coyote" <[email protected]> wrote in message
news:[email protected]...
> Anyone know of any books or articles, on-line manuals etc. that show how
to
> work with Carbon Fiber...(for bike frames would be nice), but would settle for just learning
> the basics.
 
W

Wile E.Coyote

Guest
Sooo much info...thankyou I wasn't thinking about doing an entire frame in CF, only parts that would
have sweeping curves....too hard to fabricate in metal. I'd like to find out as much as I can and
have someone to do the work for me, I know what I am capable of doing solo and have empty tool
chests and xrays to prove it.
------------------------------
"Robert Haston" <[email protected]> wrote in message
news:[email protected]...
> One piece of advice I have is to avoid trying to make a whole frame with
it.
> Carbon tubes are made with very exacting methods (low void, no bubbles, etc.) you can't match.
> They will be stronger, lighter, and prettier.
>
> Furthermore, clamping carbon cloth lugs to tubes is a far far easier
process
> than laying up a frame. http://www.calfeedesign.com/construction.shtml shows you how they
> make their custom lugged carbon bikes. You can experiment with PVC and fiberglass until you
> get it right.
>
> As to recumbents, carbon would best be suited to low racers. Carbon's stiffness allows thinner
> tubes (to go between your legs) and is better for monotube construction. Although if you want a
> frame to flex, titanium is best, and steel is proven. For items that aren't stiffness driven, such
as
> seats and such, fiberglass is stronger than steel.
>
> You can also use carbon as a way to join or reinforce aluminum. Look out for galvanic corrosion -
> west system's etch kit should work well enough. This also applies to joining crank brackets, etc.
>
> As to sanding carbon fiber. First design around having to sand. Second, trimming off the excess
> with scissors or a knife when the resin is firm is far easier and safer then sanding it when it is
> hard. Wear a mask and goggles rated for it, wet sand (under a constant spray or wash if possible)
> and do it outside in an area where the fibers won't collect and blow around when dried.
>
> All that being said, I've screwed around with aluminum and steel, and done fiberglass projects. If
> you don't have someone who can weld bikes for a decent price, a DIY carbon would be my
> recommendation.
>
>
>
> "Wile E.Coyote" <[email protected]> wrote in message
> news:[email protected]...
> > Anyone know of any books or articles, on-line manuals etc. that show how
> to
> > work with Carbon Fiber...(for bike frames would be nice), but would
settle
> > for just learning the basics.
> >
>
 
R

Robert Haston

Guest
Actually, curves are easy to do in steel. Look at the M5 Shockproof's (my bike) rear swingarm.

I must admit that a carbon seat built into the frame, or "spoon" frame is about the coolest looking
bike out there.

"Wile E.Coyote" <[email protected]> wrote in message
news:[email protected]...
> Sooo much info...thankyou I wasn't thinking about doing an entire frame in CF, only parts that
> would have sweeping curves....too hard to fabricate in metal. I'd like to find out as much as I
> can and have someone to do the work for me, I know what I am capable of doing solo and have empty
> tool chests and xrays to prove it.
> ------------------------------
> "Robert Haston" <[email protected]> wrote in message
> news:[email protected]...
> > One piece of advice I have is to avoid trying to make a whole frame with
> it.
> > Carbon tubes are made with very exacting methods (low void, no bubbles, etc.) you can't match.
> > They will be stronger, lighter, and prettier.
> >
> > Furthermore, clamping carbon cloth lugs to tubes is a far far easier
> process
> > than laying up a frame. http://www.calfeedesign.com/construction.shtml shows you how they make
> > their custom lugged carbon bikes. You can experiment with PVC and fiberglass until you get it
> > right.
> >
> > As to recumbents, carbon would best be suited to low racers. Carbon's stiffness allows thinner
> > tubes (to go between your legs) and is better
for
> > monotube construction. Although if you want a frame to flex, titanium
is
> > best, and steel is proven. For items that aren't stiffness driven, such
> as
> > seats and such, fiberglass is stronger than steel.
> >
> > You can also use carbon as a way to join or reinforce aluminum. Look
out
> > for galvanic corrosion - west system's etch kit should work well enough. This also applies to
> > joining crank brackets, etc.
> >
> > As to sanding carbon fiber. First design around having to sand.
Second,
> > trimming off the excess with scissors or a knife when the resin is firm
is
> > far easier and safer then sanding it when it is hard. Wear a mask and goggles rated for it, wet
> > sand (under a constant spray
or
> > wash if possible) and do it outside in an area where the fibers won't collect and blow around
> > when dried.
> >
> > All that being said, I've screwed around with aluminum and steel, and
done
> > fiberglass projects. If you don't have someone who can weld bikes for a decent price, a DIY
> > carbon would be my recommendation.
> >
> >
> >
> > "Wile E.Coyote" <[email protected]> wrote in message
> > news:[email protected]...
> > > Anyone know of any books or articles, on-line manuals etc. that show
how
> > to
> > > work with Carbon Fiber...(for bike frames would be nice), but would
> settle
> > > for just learning the basics.
> > >
> > >
> >
> >
 
M

Michael Perry

Guest
"Wile E.Coyote" <[email protected]> wrote in message
news:<[email protected]>...
> Sooo much info...thankyou I wasn't thinking about doing an entire frame in CF, only parts that
> would have sweeping curves....too hard to fabricate in metal. I'd like to find out as much as I
> can and have someone to do the work for me, I know what I am capable of doing solo and have empty
> tool chests and xrays to prove it.

You might also want to check out http://www.rqriley.com/xr2.html and see if they have any details as
to how they build their frames. The GH is carbon fiber, home built.
 
M

Mikael Seierup

Guest
"Steve McDonald" skrev...
>
> Ian Smith wrote:
>
> Stiffness is not synonomous with brittleness.
> ____________________________________
>
> Perhaps you can define the words "stiff" and "brittle" and indicate how either of the words
> wouldn't describe some of the characteristics of a carbon-fiber/resin product.

Aren't bikes made of carbon/kevlar anyway to get around that problem? Neither my bike nor the
tailfairing seems stiff or brittle to me.

M.
 
W

Wile E.Coyote

Guest
Curious Is CF brittle in very cold weather...has it been tested at say -25 C? Really don't
know...which is why I'm asking.
----------------------------
"Mikael Seierup" <[email protected]> wrote in message
news:[email protected]...
>
> "Steve McDonald" skrev...
> >
> > Ian Smith wrote:
> >
> > Stiffness is not synonomous with brittleness.
> > ____________________________________
> >
> > Perhaps you can define the words "stiff" and "brittle" and indicate how either of the words
> > wouldn't describe some of the characteristics of a carbon-fiber/resin product.
>
> Aren't bikes made of carbon/kevlar anyway to get around that problem? Neither my bike nor the
> tailfairing seems stiff or brittle to me.
>
> M.
 
I

Ian Smith

Guest
On Tue, 13 May 2003 02:30:03, Steve McDonald <[email protected]> wrote:
>
> Ian Smith wrote:
>
> Stiffness is not synonomous with brittleness.
> ____________________________________
>
> Perhaps you can define the words "stiff" and "brittle"

They are general words in general useage which have specific meanings. Stiffness is a property
relating how much strain occurs for a given stress (if you like, how much it deflects fro a given
load, with a given configuration). Brittleness is the inverse of toughness and is a measure of how
how likely it is to fracture.

Since you appear to be American, I will quote Mr Webster: "easily broken, cracked or snapped ...
especially under very slight bending". Since I am English, I will quote Shorter Oxford: "liable to
break; easily broken, fragile"

Stiff materials are not necesarily brittle.

Brittle materials are not necesarily stiff.

> My own usage of "stiff" would apply to something that resisted bending and "brittle" would
> describe something that would not only be stiff, but would tend to shatter if bent or impacted.

Of course you're welcome to make up your own meanings to words, but they do not appear to match
general usage.

Your meaning for 'brittle' appears to be that the material does not exhibit plasticity before
fracture. It may be immensely tough (ie not at all brittle, not easy to fracture) and not exhibit
plasticity.

CFRP is not necesarily brittle. A fairly standard grade used in my own industry is pultruded strips
with E around 150 to 165 kN/mm2. Elongation at break is around 0.017. That's a large strain for
engineering materials (mild steel, for example, yields at about 0.001, concrete can start to crush
at about 0.0035). It certainly isn't easily broken under very slight bending.

regards, Ian SMith
--
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|o o|
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T

Tom Sherman

Guest
Ian Smith wrote:
>
> On Tue, 13 May 2003 02:30:03, Steve McDonald <[email protected]> wrote:
> >
> > Ian Smith wrote:
> >
> > Stiffness is not synonomous with brittleness.
> > ____________________________________
> >
> > Perhaps you can define the words "stiff" and "brittle"
>
> They are general words in general useage which have specific meanings. Stiffness is a property
> relating how much strain occurs for a given stress (if you like, how much it deflects fro a given
> load, with a given configuration). Brittleness is the inverse of toughness and is a measure of how
> how likely it is to fracture....

A brittle material fractures without gross local yielding, while a ductile material will
exhibit a considerable amount of plastic deformation before fracture occurs. Brittle is the
opposite of ductile.

The resistance to crack propagation is fracture toughness. Ductile materials generally have greater
fracture toughness, but there is not necessarily a direct correlation between ductility and fracture
toughness.

Tom Sherman - Various HPV's Quad Cities USA (Illinois side)
 
I

Ian Smith

Guest
On Tue, 13 May 2003, Steve McDonald <[email protected]> wrote:
>
> The evaluation of carbon-fiber products, as with those made of any reinforcing fiber, has to
> include the performance specs of the plastic or resin component of the fiber-reinforced
> product (FRP) to be pertinent to any application

Yes, and as I stated, my example was for a pultruded strip - ie, was the performance of the
composite, fibers and resin. Saying I have to take account of what I have already taken account of
(and told you that I was doing so) doesn't move discussion forward much.

> has much value to an engineer. Often, the characteristics of each component as a separate
> material, can't accurately be used as predictors of their combined performance.

I wasn't talking about individual components, I gave you an example of a composite, and I stated
that was what I was doing (it's about a 70% fibre fraction, and I think it's an epoxy matrix, as
it happens)

regards, Ian SMith
--
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|o o|
|/ \|
 
I

Ian Smith

Guest
On Wed, 14 May 2003 00:49:37 -0500, Tom Sherman <[email protected]> wrote:
>
> Ian Smith wrote:
> >
> > On Tue, 13 May 2003 02:30:03, Steve McDonald <[email protected]> wrote:
> > >
> > > Ian Smith wrote:
> > >
> > > Stiffness is not synonomous with brittleness.
> > > ____________________________________
> > >
> > > Perhaps you can define the words "stiff" and "brittle"
> >
> > given configuration). Brittleness is the inverse of toughness and is a measure of how how likely
> > it is to fracture....
>
> A brittle material fractures without gross local yielding, while a ductile material will exhibit
> a considerable amount of plastic deformation before fracture occurs. Brittle is the opposite of
> ductile.

Not in my opinion, brittle is the oppositte of tough. I guess me, Merriam-Webster and Oxford
dictionaries will just have to agree to all disagree with you.

Anyway, even with your definition, stiffness is not synonymous with brittleness, which was my
original assertion, or are you going to claim there are no stiff materials that exhibit ductility?

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|
 
T

Tom Sherman

Guest
Ian Smith wrote:
>
> On Wed, 14 May 2003 00:49:37 -0500, Tom Sherman <[email protected]> wrote:
> >
> > Ian Smith wrote:
> > >
> > > On Tue, 13 May 2003 02:30:03, Steve McDonald <[email protected]> wrote:
> > > >
> > > > Ian Smith wrote:
> > > >
> > > > Stiffness is not synonomous with brittleness.
> > > > ____________________________________
> > > >
> > > > Perhaps you can define the words "stiff" and "brittle"
> > >
> > > given configuration). Brittleness is the inverse of toughness and is a measure of how how
> > > likely it is to fracture....
> >
> > A brittle material fractures without gross local yielding, while a ductile material will
> > exhibit a considerable amount of plastic deformation before fracture occurs. Brittle is the
> > opposite of ductile.
>
> Not in my opinion, brittle is the oppositte of tough. I guess me, Merriam-Webster and Oxford
> dictionaries will just have to agree to all disagree with you.
>
> Anyway, even with your definition, stiffness is not synonymous with brittleness, which was my
> original assertion, or are you going to claim there are no stiff materials that exhibit ductility?

My definitions are those used by metallurgists, mechanical engineers, and materials
engineers/scientists. [1]

Stiffness is a vague term, as it is not clear whether it refers to the intrinsic material property
or that of a structural member. The intrinsic measure of material stiffness is the elastic, or
Young's modulus. The stiffness of a structural member will depend on the Young's modulus and the
moment of inertia about the axis of bending. These are measured in the elastic range of the
material/member, so there is no relationship between stiffness and brittleness/ductility.

[1] I used to teach laboratory testing methods for a properties of engineering materials class, so I
do happen to be familiar with the tests used to determine yield and ultimate strength
(compressive and tensile), ductility, hardness, elastic modulus, shear modulus, modulus of
rupture, fracture toughness, notch sensitivity and creep.

Tom Sherman - Various HPV's Quad Cities USA (Illinois side)
 
I

Ian Smith

Guest
On Thu, 15 May 2003 01:12:53 -0500, Tom Sherman <[email protected]> wrote:
>
> Ian Smith wrote:
> >
> > On Wed, 14 May 2003 00:49:37 -0500, Tom Sherman <[email protected]> wrote:
> > >
> > > Ian Smith wrote:
> > > >
> > > > On Tue, 13 May 2003 02:30:03, Steve McDonald <[email protected]> wrote:
> > > > >
> > > > > Ian Smith wrote:
> > > > >
> > > > > Stiffness is not synonomous with brittleness.
> > > > > ____________________________________
> > > > >
> > > > > Perhaps you can define the words "stiff" and "brittle"
> > > >
> > > > given configuration). Brittleness is the inverse of toughness and is a measure of how how
> > > > likely it is to fracture....
> > >
> > > A brittle material fractures without gross local yielding, while a ductile material will
> > > exhibit a considerable amount of plastic deformation before fracture occurs. Brittle is the
> > > opposite of ductile.
> >
> > Not in my opinion, brittle is the oppositte of tough. I guess me, Merriam-Webster and Oxford
> > dictionaries will just have to agree to all disagree with you.
> >
> > Anyway, even with your definition, stiffness is not synonymous with brittleness, which was my
> > original assertion, or are you going to claim there are no stiff materials that exhibit
> > ductility?
>
> Stiffness is a vague term, as it is not clear whether it refers to the intrinsic material
> property or that of a structural member.

When we're exclusively discussing materials (as we have been) it is perfectly clear which we are
referring to. Structural members have not been brought up by anyone until now, when you apparently
decide to try and confuse the issue.

> measured in the elastic range of the material/member, so there is no relationship between
> stiffness and brittleness/ductility.

Absolutele, so my statement "stiffness is not synonymous with brittleness" was 100% correct. Thank
you for your (eventual) agreement.

regards, Ian SMith
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|o o|
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H

Harv

Guest
snip

> notch sensitivity and creep.
>
> Tom Sherman - Various HPV's Quad Cities USA (Illinois side)

So in this case, you're not talking about Flabbio wearing an Izod shirt?
 
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